Coyote Blog

On several occasions, I have discussed how much of the reported temperature increases worldwide in the last century are actually the results of adjustments to the actual gauge measurements.  These upward adjustments in the numbers by climate scientists actually dwarf measured increases.

Thanks to reader Scott Brooks, here is another such example except this time with measurement of sea level increases.  Dr. Nils-Axel Morner is the head of the Paleogeophysics and Geodynamics department at Stockholm University in Sweden.  He has studied sea-level changes for 35 years (emphasis added).

Another
way of looking at what is going on is the tide gauge. Tide gauging is
very complicated, because it gives different answers for wherever you
are in the world. But we have to rely on geology when we interpret it.
So, for example, those people in the IPCC [Intergovernmental Panel on
Climate Change], choose Hong Kong, which has six tide gauges, and they
choose the record of one, which gives 2.3 mm per year rise of sea
level. Every geologist knows that that is a subsiding area. It's the
compaction of sediment; it is the only record which you shouldn't use.
And if that figure [for sea level rise] is correct, then Holland would not be subsiding, it
would be uplifting.

And
that is just ridiculous. Not even ignorance could be responsible for a
thing like that. So tide gauges, you have to treat very, very
carefully. Now, back to satellite altimetry, which shows the water, not
just the coasts, but in the whole of the ocean. And you measure it by
satellite. From 1992 to 2002, [the graph of the sea level] was a
straight line, variability along a straight line, but absolutely no
trend whatsoever. We could see those spikes: a very rapid rise, but
then in half a year, they fall back again. But absolutely no trend, and
to have a sea-level rise, you need a trend.

Then,
in 2003, the same data set, which in their [IPCC's] publications, in
their website, was a straight line suddenly it changed, and showed a
very strong line of uplift, 2.3 mm per year, the same as from the tide
gauge. And that didn't look so nice. It looked as though they had
recorded something; but they hadn't recorded anything. It was the
original one which they had suddenly twisted up, because they entered a correction factor, which they took from the tide gauge. So it was not
a measured thing, but a figure introduced from outside. I accused them
of this at the Academy of Sciences in Moscow I said you have
introduced factors from outside; it's not a measurement. It looks like
it is measured from the satellite, but you don't say what really
happened. And they ans-wered, that we had to do it, because otherwise
we would not have gotten any trend!

That
is terrible! As a matter of fact, it is a falsification of the data
set. Why? Because they know the answer. And there you come to the
point: They know the answer; the rest of us, we are searching for the
answer. Because we are field geologists; they are computer scientists.
So all this talk that sea level is rising, this stems from the computer
modeling, not from observations. The observations don't find it!

I have
been the expert reviewer for the IPCC, both in 2000 and last year. The
first time I read it, I was exceptionally surprised. First of all, it
had 22 authors, but none of them  none were sea-level specialists. They
were given this mission, because they promised to answer the right
thing. Again, it was a computer issue. This is the typical thing: The meteorological community works with computers, simple computers.

Geologists
don't do that! We go out in the field and observe, and then we can try
to make a model with computerization; but it's not the first thing.

I am working on my next version of a layman's guide to skeptics arguments against catastrophic man-made global warming, which you can find here.

I was trying to think about what I wanted to do for my last post in my recent orgy of global warming writing.  My original attempt to outline the state of the climate skeptic's case ballooned into 80+ pages, so there may be many people who rationally just have no desire to tackle that much material.  So I decided for this last post to try to select the one argument I would use if I had only 60 seconds to make the climate skeptic's case. But how do you boil down 80 pages to a few simple statements?

I'm not that interested in the Sun or cosmic rays -- they are interesting topics, but its dumb to try to argue we overestimate our understanding of man's impact on climate only to counter with topics we understand even less.  One of the reasons I wrote the paper in the first place was because I thought recent skeptical documentaries spent too much time on this subject.  And I would not get into tree rings or ice cores or other historic proxy data, though there is a lot happening in these areas.  I wouldn't even delve into the hysterical treatment of skeptics by man-made climate advocates  -- these are ad hominem issues that are useful to understand in a more comprehensive view but don't make for strong stand-alone arguments.

Anyway, here goes, in a logic chain of 8 steps.

1. CO2 does indeed absorb reflected sunlight returning to space from earth, having a warming effect.  However, this effect is a diminishing return -- each successive increment of CO2 concentrations will have a much smaller effect on temperatures than the previous increment.  Eventually, CO2 becomes nearly saturated in its ability to absorb radiation.  The effect is much like painting a red room with white paint.  The first coat covers a lot of red but some still shows through.  Each additional coat will make the room progressively whiter, but each successive coat will have a less noticeable effects than the previous coat, until the room is just white and can't get any whiter.
2. In the 20th century, the UN IPCC claims Earth's surface temperatures have increased by about a 0.6 degree Celsius (though there are some good reasons to think that biases in the installation of temperature instruments have exaggerated this apparent increase).  To be simple (and generous), let's assume all this 0.6C increase is due to man-made greenhouse gasses.  Some may in fact have been due to natural effects, but some may also have been masked by man-made sulfate aerosols, so lets just call man-made warming to be 0.6C. 
3. Since the beginning of the industrial revolution, it is thought that man has increased atmospheric CO2 concentrations from 0.028% of the atmosphere to 0.038% of the atmosphere.  Since scientists often talk about the effect of a doubling of CO2, this historic rise in CO2 is 36% of a doubling.
4. Using simple math, we see that if temperatures have risen 0.6C due to 36% of a doubling, we might expect them to rise by 1.67C for a full doubling to 0.056% of the atmosphere.  But this assumes that the rise is linear -- and we already said (and no one denies) that it is in fact a diminishing return relationship.  Using a truer form of the curve, a 0.6C historic rise for 36% of a doubling implies a full doubling would raise temperatures by about 1.2C, or about 0.6C more than we have seen to date (see chart below).   This means that the magnitude of global warming in the next century might be about what we have seen (and apparently survived) since 1900.



5. Obviously, there is some kind of disconnect here.  The IPCC predicts temperature increases in the next century of 4-8 degrees C.  Big difference.  In fact, the IPCC predicts we will get a 0.5C rise in just 20 years, not 70-100.  Whereas we derived a climate sensitivity of 1.2 from empirical data, they arrive at numbers between 3 and 4 or even higher for sensitivity.  The chart below shows that to believe sensitivity is 3, we would have to have seen temperature rises due to man historically of 1.5C, which nobody believes. 

   

   So how do they get accelerating temperatures from what they admit to be a diminishing return relation between CO2 concentration and temperature? And for which there is no empirical evidence?  Answer:  Positive feedback.

6. Almost every process you can think of in nature operates by negative
   feedback.  Roll a ball, and eventually friction and wind resistance bring
   it to a stop.  Negative feedback is a ball in the bottom of a bowl; positive feedback is a ball perched precariously at the time of a mountain. Positive feedback
   breeds instability, and processes that operate by positive feedback are
   dangerous, and usually end up in extreme states -- these processes tend to
   "run away" like the ball rolling down the hill.  Nuclear fission, for example, is a positive feedback process.  We should be happy there are not more positive feedback
   processes on our planet.  Current man-made global warming theory, however, asserts that our climate is dominated by positive feedback.  The IPCC posits that a small increase in temperature from CO2 is multiplied 2,3,4 times or more by positive feedbacks like humidity and ice albedo.
7. There are three problems with these assumptions about positive feedback.  One, there is no empirical evidence at all that positive feedbacks in climate dominate negative feedbacks.   The 20th century temperature numbers we discussed above show no evidence of these feedbacks.  Two, the long-term temperature record demonstrates that positive feedbacks can't dominate, because past increases in temperature and CO2 have not run away.  And three, characterizations of stable natural processes as being dominated by positive feedback should offend the intuition and common sense of any scientist.
8. An expected 21st century increase of 0.5 or even 1 degree C does not justify the massive imposed government interventions that will be costly both in dollars and lost freedoms.  In particular, the developing world will be far better off hotter by a degree and richer than it would be cooler and poorer.  This is particularly true since sources like an Inconvenient Truth wildly exaggerate the negative effects of global warming.  There is no evidence tornadoes or hurricanes or disease or extinction are increasing as the world warms, and man-made warming advocates generally ignore any potential positive effects of warming.  As to rising sea levels, the IPCC predicts only a foot and a half of sea level rise even with 4 or more degrees of warming.  Sea level rise from a half to one degree of warming would be measured at most in inches.

OK, so that was more than 60 seconds.  But it is a lot less than 80 pages.  There is a lot of complexity behind every one of these statements.  If you are intrigued, or at least before you accuse me of missing something critical, see my longer paper on global warming skepticism first, where all these issues and much more (yes, including tree rings and cosmic rays) are discussed in more depth.

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

 For the first time since the Catholic Church
dominated western man's affairs, it has suddenly become a sin again to be
labeled a "skeptic."  For most of my lifetime, "skepticism" was considered
an essential element in the makeup of any good scientist (or journalist, for
that matter).   However, leading world figures are declaring
skepticism to be immoral.  Take one example, from this UPI
story:

A former chief of the U.N. World
Health Organization who also is a former prime minister of Norway and a medical
doctor has declared an end to the climate-change debate.

Dr. Gro Harlem Brundtland, one of U.N.
Secretary-General Ban Ki-moon's three new special envoys on climate change, also headed up the 1987 U.N. World
Commission on Environment and Development where the concept of sustainable
development was first floated.

"This discussion is behind us. It's
over," she told reporters. "The diagnosis is clear, the science is
unequivocal -- it's completely immoral, even, to question now, on the basis of
what we know, the reports that are out, to question the issue and to question
whether we need to move forward at a much stronger pace as humankind to address
the issues."

In its most extreme form, this approach has AGW supporters
labeling skeptics as equivalent to "holocaust deniers" and "tobacco
lawyers."  Efforts have been made in several quarters to decertify
climatologists or meteorologists who show any skepticism for AGW theory, making
public adherence to the theory a minimum qualification for publication and
professional standing.  Enormous efforts are made to squelch skeptical
speech.  Just as one example, the BBC has run a zillion shows and specials
sympathetic to AGW.  When Channel 4 ran one single show (called the
"Global Warming Swindle") which outlined parts of the skeptics' position, 37 scientists attempted to have it
suppressed by the government.

This is all the more incredible given that AGW theory has
only really been researched seriously and with any critical mass for about 20
years.  Anyone who has studied the history of science will understand what
incredible hubris it is to declare any new scientific theory, particularly one
that concerns the unbelievably chaotic climate, as "done" after just 20 years
work. 

Let me give two quick examples of just how unsettled the
science of climate change is.  Both of these will be reviewed in more
depth later in this paper, and both analyses figured prominently in the third
IPCC report (2001) as well as Al Gore's An Inconvenient Truth.  The
first is a 100,000 year temperature and CO2-level reconstruction from ice-core
data.  Anyone who saw Gore's movie will remember the data in one of his
Really Big Charts.  And it looks compelling "“ in fact, when I first saw
the chart five years ago, it was compelling to me.  It shows CO2 levels
and temperature moving in lock-step for 100,000 years.  When CO2 is up,
temperature is up and vice-versa, the clear implication being that CO2 seems to
be a key, maybe the key, driver of climate   However, since
that chart was first prepared, laboratory procedure has improved, and
scientists have found (and there is very little disagreement about this, even
among strong AGW supporters) that temperature increases occur on average 800
years before the CO2 starts to increase.  Huh.  There is a lot
of debate about what this means, but in the last five years, this formerly definitive
analysis is clearly no longer definitive, since it is hard to cause something
after the fact.

The other example is the very famous Mann hockey stick
chart, prominently featured in Gore's movie and a key part of the IPCC report
in 2001.  I will go into the details later, but since 2001 this analysis
has been effectively discredited, so much so it was almost entirely missing
from the fourth IPCC report in 2007.  In 2003 or so, Al Gore and many AGW
supporters would have called the Mann hockey stick chart the single most
important analysis "proving" AGW, and Gore treated it as such in his PowerPoint
deck and his movie.  Then, in 2007, it is repudiated and expunged from the
record.  Is this really what any reasonable person would call a "settled"
science?

It is a true perversion of the scientific process to find
that skepticism is no longer welcome or accepted in scientific debate.
Which is one reason that AGW is sometimes called a secular religion.
Because it is religion, not science, that burns skeptics at the stake.  Climate
Scientists Garth Paltridge wrote:

A colleague of mine put it rather
well. The IPCC, he said, has developed a highly successful immune system. Its
climate scientists have become the equivalent of white blood cells which rush
in overwhelming numbers to repel infection by ideas and results which do not
support the basic thesis that global warming is perhaps the greatest of the
modern threats to mankind.

Charges of Bias

A funny thing has happened in climate science to scientific inquiry:
the usual ethics of free discussion and fact-based criticism have been
discarded in favor of ad hominem attacks on critics of AGW theory.
The usual approach is to find some connection (even an imagined one) between
any researcher who raises the smallest doubts about AGW theory and an oil or
power company and then declare that the research is tainted by the bias of
these companies that have a strong economic reliance on fossil fuel combustion
(and thus the production of CO2).  A good example can be found in a Boston
Globe article on MIT's Alfred P. Sloan professor of meteorology Richard
Lindzen.  Mr. Lindzen has become the bete noir of AGW supporters,
since his skepticism is harder to dismiss given his scientific pedigree and his
co-lead author status on the first IPCC climate change report.

"We do not understand the natural internal
variability of climate change" is one of Lindzen's many heresies, along
with such zingers as `"the Arctic was as warm or warmer in 1940,"
"the evidence so far suggests that the Greenland ice sheet is actually
growing on average," and "Alpine glaciers have been retreating since
the early 19th century, and were advancing for several centuries before that.
Since about 1970, many of the glaciers have stopped retreating and some are now
advancing again. And, frankly, we don't know why."

When Lindzen published similar views in The Wall
Street Journal this spring, environmentalist Laurie David, the wife of comedian
Larry David, immediately branded him a "shill." She resurrected a
shopworn slur first directed against Lindzen by former Globe writer Ross
Gelbspan, who called Lindzen a "hood ornament" for the fossil fuels
industry in a 1995 article in Harper's Magazine....

For no apparent reason, the state of California,
Environmental Defense, and the Natural Resources Defense Council have dragged
Lindzen and about 15 other global- warming skeptics into a lawsuit over auto-
emissions standards. California et al. have asked the auto companies to cough
up any and all communications they have had with Lindzen and his colleagues,
whose research has been cited in court documents.

"We know that General Motors has been paying
for this fake science exactly as the tobacco companies did," says ED
attorney Jim Marston. If Marston has a scintilla of evidence that Lindzen has
been trafficking in fake science, he should present it to the MIT provost's
office. Otherwise, he should shut up.

"This is the criminalization of opposition to
global warming," says Lindzen, who adds he has never communicated with the
auto companies involved in the lawsuit.

While I have no doubt that corporations are heavily
influenced by their own economic interests, it is more of stretch to argue that
anyone who has ever taken money from them or had any connection with them would
purposely bias their research.  When I learned to debate, I was taught
that understanding biases was useful in knowing when to apply more or less
skepticism, but one still has to refute the opposing position by meaningful
critique of procedures or data.   For example, one might say "given
their strong desire to buttress the case for AGW, the researchers cherry-picked
only the most extreme data, which I will demonstrate by showing the data they
included and the data they chose to exclude."  However, many modern AGW
supporters believe that insinuating possible sources of bias is sufficient to
exempt one from having to actually critique their opponents' methods and
findings. 

This is particularly odd given that public funding for AGW
projects absolutely dwarfs any funding coming from private sources whose
incentive might be to disprove AGW.  In fact, just this year, President
Bush declared that the US Government alone spent more money on AGW research
than on AIDS research, and the US is actually late in the climate funding
game. 

Recently, Greenpeace criticized ExxonMobil for exercising
its free speech rights and giving
about $2 million to global warming skeptics. 

Still, the Greenpeace report is already receiving
scrutiny in Washington, where Rep. Brad Miller, a North Carolina Democrat, has
joined the environmentalist group in calling for Exxon to release its plans for
contributions during the current year.

"The support of climate skeptics, many of whom
have no real grounding in climate science, appears to be an effort to distort
public discussion about global warming," Miller said. "So long as
popular discussion could be about whether warming was occurring or not, so long
as doubt was widespread, consensus for action could be postponed."

Incredibly, at these spending rates, skeptics are getting outspent by AGW
supporters something like 1000:1 or more.  It is astounding that AGW
supporters, with such a huge funding and publication advantage, still feel
threatened by critics.

Climate research, once a sleepy academic backwater, is now a
multi-billion dollar industry.  This boom in spending is because of fears
of AGW, and should AGW theory be discredited, this funding will quickly dry
up.  So funding for climate researchers exists only as long as climate
researchers beat the drum that AGW is a large threat.   It strikes me
that this is at least as large an incentive for bias as that of any
Exxon-funded skeptic.   Here's another way to look at it:  If
AGW theory is proven correct, the likely political response might cut Shell's
revenues by 20-30%, at most.  If AGW theory is proven incorrect, then
university climate research funding might be cut by 100%.
  Directionally, all the incentives in academia are to inflate global
warming projections.  No one is going to make the news, or even continue
to get funding, if they argue that warming will only be a degree or two in the
next century.  The guys that get the fame and the grants are those pushing
the numbers higher and higher.

Certainly AGW supporters claim that academic researchers are
only concerned about the science and are not concerned about the funding
incentives.  This may be true (though a bit naïve, for anyone who has been
in a university environment and sought research funding), but if pro-AGW
researchers are not swayed by the funding, then it should be equally true that
AGW skeptics are not swayed by much smaller amounts of money flowing to
them.    Any argument that tries to claim that these situations
are somehow different just ends up being circular, i.e. "it's OK if our guys do
it because our guys are right."

One of the mistakes the IPCC process has systematically made
is to make the lead author's and reviewers of many of its report sections a
scientist whose research is mostly in that area.  While this makes a
certain sense, as these people will be expert in their particular area of
review, it presents them with a huge conflict of interest.  For example,
Michael Mann used his own historical temperature reconstructions as the lead
analysis in the section of the third IPCC report for which he was lead
author.  Clearly, one wouldn't expect him to be (nor was he) open to any
research or issues or criticisms aimed at his own work.  In the fourth
report, the new lead author who replaced Mann on this section (Biffra) did the
exact same thing Mann did "“ used his own work as centerpiece of the section,
and has refused to even consider criticisms about that work. 

Just to avoid future argument, I
will outline my potential biases.  I own a small recreation business which
depends on people traveling to beautiful, natural settings.  I lose
business when the climate changes (e.g. when lakes dry up next to my
facilities, which has happened to me).  I generally gain business when gas
prices increase, as they might under various anti-global warming mandates,
since my facilities tend to be short-drive weekend destinations rather than cross-country
destinations.  I grew up in Houston, Texas, so most of my family has
worked in the oil industry at one time or another, and I worked for the Great
Satan Exxon as my first job for three years out of college.  I am a
libertarian blogger at CoyoteBlog.com, and am suspicious of government
interventions but have historically supported emissions limits where they make
sense.  No one has contributed any money to me for this paper or for the
operation of my blog.

The Climate Trojan
Horse

To fully understand the passionate, almost dogmatic
dedication so many people have to AGW theory, it is a bit useful to look at a
little history.  After the fall of the Soviet Union in 1989, there were a
lot of Marxists, socialists, anti-corporatists and anti-capitalists who were
looking for a new way to package and reinvent themselves, given that the vast
majority of people (at least in the West) considered socialism failed and no
longer wanted to hear about it any more.  For a while, many of these folks
latched onto the anti-globalization cause.  Every interview I ever saw of
one of these anti-globalization guys was a real mess of disorganized beliefs,
but one could tell the movement was the new home for anyone who wanted to stop
the spread of capitalism and privately-owned business. 

Then, along came anthropogenic global warming.  Here
was a theory and movement that united many disparate interests:

• Socialists, communists, and Marxists
• Anti-capitalists
• Anti-consumerists
• Those opposed to large corporations
• Those opposed to global free trade
• Those opposed to economic development and growth, longing
       for simplicity
• "Buy local" movements
• People who just hate oil companies

Suddenly, here was a big tent for all of these causes.
I highly encourage you to view a global warming rally.  Don't just watch
the snippets on the evening news, those usually highlight the most reasonable
speakers at the rally.  Actually go and watch the whole event.  What
you will see is far more anti-corporate, anti-oil company, anti-capitalist
rhetoric than you will hear climate science and discussion.  The two
rallies I have seen with my own eyes were Marxist rallies under a climate
banner.  As an admittedly extreme example, I will refer you to the words of
Paul
Watson, Founder and President of Sea Shepherd Conservation Society, who
offers his group's vision.  While this particular vision pre-dated most
discussions of AGW, I hope you can see how AGW fear-mongering provides quite a
useful vehicle for groups of this type:

"We need to radically and
intelligently reduce human populations to fewer than one billion.... We need to
stop burning fossil fuels and utilize only wind, water, and solar power with
all generation of power coming from individual or small community units like
windmills, waterwheels, and solar panels. Sea transportation should be by
sail.... Air transportation should be by solar powered blimps when air
transportation is necessary. All consumption should be local. No food products
need to be transported over hundreds of miles to market. All commercial fishing
should be abolished. If local communities need to fish the fish should be
caught individually by hand. Preferably vegan and vegetarian diets can be
adopted.... We need to remove and destroy all fences and barriers that bar
wildlife from moving freely across the land.... We need to stop flying, stop
driving cars, and jetting around on marine recreational vehicles.... Who should
have children? Those who are responsible and completely dedicated to the
responsibility which is actually a very small percentage of humans...."

Of course what he doesn't say, but is an explicit outcome of
this vision, is that we can all go back to being dirt poor and having a life
expectancy of about 40 years.

The average person, say in America, wants little to do with
any of this.  But fear of AGW provides a way to engage everyone in the
movement.  Socialists of all stripes no longer have to spew Marxist
notions that turn most people off; now, they can talk the science of global
warming and hurricanes and massive floods and such, and, using fear, trample
the average guy into their socialist goals of stifling capitalism, growth, and
having the government take over the economy through this environmental
back-door.

The Need to
Exaggerate

One of the hardest parts of really trying to understand what is going on in
the AGW scientific debate is separating the scientists doing real science from
the political advocates, who sometimes carry quasi-scientific titles.  A
very, very small number of vocal climate scientists and a somewhat larger group
of what I would call advocates and bureaucrats really determine what you hear
in the media about AGW science.   A great example is the UN IPCC
reports.  Unless you have gone online and dug into the detailed reports
themselves, likely all you have seen from these reports is taken out of the
management summaries "for policy-makers".  These summaries are written by
bureaucrats and advocates, not so much by scientists, and tend to wildly
mis-characterize the true state of the science.   Careful language in
the heart of the reports expressing uncertainty and low understanding of
certain phenomena are cast aside in the summaries, in favor of a comforting
certainty and absolutes.  In earlier IPCC reports, this caused notable
disconnects between the summaries and the detailed science.  More
recently, the UN has "fixed" this problem by having their non-scientists write the
conclusions in the management summaries first, and then telling authors of the
individual sections of the report to conform their writing, and their science,
to the summary.  So, for the Fourth IPCC report, the summary was published
over a half year before the science!

As a result, while the IPCC reports claim to be the consensus of 5000
scientists, actually less than half would willingly sign their name to the
management summaries of their work that you see in the press.  The
management summaries and related press releases have become more political
advocacy than science, as UN bureaucrats use AGW-fear-mongering to increase
their prestige and power.  Generally, these summaries and press releases
are taken more seriously by the press than they are climate scientists.
You can get an insight on the IPCC process just by looking at how they select
their co-lead authors on certain sections.  A logical way to choose these
authors would be to find scientists who bring a different scientific perspective
"“ maybe a leading astronomer who studies the sun, maybe someone who studies
hurricanes, or perhaps even, gasp, a skeptic or two.  This is not how the
IPCC makes the selection.  Instead, they focus on including scientists,
often with limited experience or expertise, who bring geographic or ethnic
diversity to the panel.  Nothing better demonstrates that the IPCC is
first and foremost a political entity, and a scientific body second (at best).

If I seem too hard on the climate science community, then consider this quote
from National Center for Atmospheric Research (NOAA) climate researcher and
global warming action promoter, Steven Schneider:

We have to
offer up scary scenarios, make simplified, dramatic statements, and make little
mention of any doubts we have. Each of us has to decide what the right balance
is between being effective and being honest.

Is that how you learned science in high school "“ that lying
about the science was OK if it makes you more politically effective?  Der
Spiegel, a magazine historically sympathetic to the AGW cause, published
this analysis:

This doesn't mean that Gore should necessarily be
taken to task for his statements. He is a politician. But it is odd to hear
IPCC Chairman Pachauri, when asked what he thinks about Gore's film,
responding: "I liked it. It does emotionalize the debate, but it seems
that it has to do that." And when Pachauri comments on the publication of
the first SPM by saying, "I hope that this will shock the governments so
much that they take action," this doesn't exactly allay doubts as to his
objectivity. When Renate Christ, the secretary of the IPCC, is asked about her
opinion of reporting on climate change, she refers to articles that mention
"climate catastrophe" and calls them "rather refreshing." .
. .

The problem is that the IPCC is not a political
group whose goal is to exert pressure, but a scientific institution and panel
of experts. Its members ought to present their results and analyses
dispassionately, the way pathologists or psychiatrists do when serving as
expert witnesses in court, no matter how horrible the victim's injuries and how
deviant the perpetrator's psyche are.

I will end this section on an admittedly extreme example
of a headline taken from the Canadian, a "progressive" magazine up in
the Great White North.  In the great race to one-up other media outlets in
creating a panic, and not happy with just a few more hurricanes or some melted
icebergs, the Canadian has taken the prize.  Get ready for it"¦

"Over 4.5 Billion people could die
from Global Warming-related causes by 2012"

In case you are struggling with the math, that means that they believe
Global Warming could kill three quarters of the world's population in the next
five years.  And the media treats these people with total respect, and we
skeptics are considered loony?

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

The open comment thread for this paper can be found here. 

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

We have gotten well into this paper, and we still have not
discussed what is perhaps the most problematic aspect of AGW research:
the computer models.

If an economist came up with a computer model that he claimed could predict
the market value of every house in the world in the year 2106 within $1,000,
would you believe him?  No, you would say he was nuts -- there is way too
much uncertainty and complexity.  Climate, of course, is not the same as
housing prices.  It is in fact, much, much more complex and more difficult
to predict.  There is nothing wrong with trying to predict the complex and
chaotic.  But there is a certain sense of hubris in believing that one has
succeeded with the kind of 95% certainty figures used by the IPCC.

All climate forecasting models are created by a pretty insular and
incestuous climate science community that seems to compete to see who can come
up with the most dire forecast.  Certainly there are financial incentives
to be as aggressive as possible in forecasting climate change, since funding
dollars tend to get channeled to those who are the most dramatic.
The global warming community spends a lot of time with ad hominem attacks
on skeptics, usually accusing them of being in the pay of oil and power
companies, but they all know that their own funding in turn would dry up
rapidly if they were to show any bit of skepticism in their own work.

The details of these models is beyond the scope of this paper.
However, it is important to understand how they work in broad outlines.

The modelers begin with certain assumptions about climate that they build
into the model.  For example, the computers themselves don't somehow
decide if CO2 is a more important forcing on the climate than solar activity "“
the modelers, by the assumptions the feed into the model, decide these
things.  The models return the result that CO2 is the most important
driver of climate in the coming century because their programmers built them
with that assumption, not because the model somehow sorts through different
inputs and comes up with the key drivers on its own.

Because the models have been built to test man's possible impact on the
climate via greenhouse gas emissions, they begin with an econometric forecast
of world economic growth, and, based upon assumptions about fuel sources and
efficiencies, they convert this economic growth into emissions forecasts.
The models generally contain subroutines that calculate, again based upon a
variety of assumptions, how man-made CO2 plus other inputs will change the
atmospheric CO2 concentration.  Then, via assumptions about climate
sensitivity to CO2 and various feedback loops programmed in, the models will
create forecasts of temperatures, precipitation, etc.  These models,
depending on their complexity, will show regional variations in many of these
variables.  Finally, the models are tuned so that they better match
history, in theory making them more accurate for the future.

One should note that while the IPCC asked modelers to look at a series of
different cases, the only substantial difference between these cases is the
volume of CO2 and other greenhouse gasses produced.  In other words, the
only sensitivity the IPCC seriously modeled was on levels of CO2.  No
other contingency "“ e.g. potential variations in global temperature sensitivity
to CO2, solar output, land use "“ were considered.  This should give you an
idea of how hard-wired the anthropogenic causation is in the IPCC process.

In this section, I will begin by discussing the models' basic assumptions
about the climate.  I will then discuss the econometric forecasts they are
founded on, the assumptions about CO2 sensitivity and feedback processes, and
finally model tuning and their ability to match history.

The Dangers in Modeling Complex Systems

At any one time, thousands of people are being paid literally millions of
dollars on Wall Street to try to model the behavior of various stock indices
and commodity prices.  The total brain power and money power thrown over
the last 50 years at trying to build an accurate predictive model for financial
markets literally dwarfs, by a factor of 100 or more, the cumulative resources
spent to date on long-term climate modeling.  Financial markets are
incredibly complex, and they are driven by hundreds of variables.
Interest rates, corporate profits, loan default rates, mortgage refinance
rates, real estate prices, GDP growth, exchange rates, etc. all tend to drive
the behavior of financial markets.  And no one has cracked the code.
Sure, some people have built successful short-term trading models, but people
have mostly lost their shirts when they have tried to make long-term bets based
on computer financial models that beautifully matched history but failed to
accurately predict the future.

How is it possible that a model that accurately represents the past fails to
accurately predict the future?  Financial modelers, like climate modelers,
look to history in building their models.  Again, like climate modelers,
they rely both on theory (e.g. higher interest rates should generally mean
lower stock prices) as well as observed correlations in the historic data
set.  The problem they meet, the problem that every modeler meets but most
especially the climate modeler, is that while it is easy to use various
analysis tools to find correlations in the data, there is often nothing that
will tell you if there is really a causal relationship, and which way the
causality runs. For example, one might observe that interest rates and exchange
rates move together.  Are interest rate changes leading to exchange rate
adjustments, or vice versa?  Or, in fact, are they both caused by a third
variable?  Or is their observed correlation merely coincidence?

It was once observed that if an old AFL football team wins the Superbowl, a
bear market will ensue on Wall Street in the next year, while an NFL team
victory presaged a bull market.  As of 1997, this correlation held for 28
of the last 31 years, a far better prediction record than that of any Wall
Street analyst.  But of course this correlation was spurious, and in the
next 4 years it was wrong every time.  Had someone built a financial model
on this indicator, it would have looked great when he ran it against history,
but he would have lost his shirt using it. 

Want a better prediction record?  For seventeen straight US
presidential election cycles, from 1936 to 2000, the winner of the election was
accurately predicted by"¦the Washington Redskins.  In particular, if the
Redskins won their last home game before the election, the party that occupies
the White House holds it in the election.  Otherwise, if the Redskins
lose, the opposition party wins.  Seventeen in a row!  R-squared of
one!  Success against odds of 131,072:1 of guessing all 17 right.
But of course, the input was spurious, and in 2004, soon after this
relationship made the rounds of the Internet, the algorithm failed.

This is why we spent so much time in the previous chapter on evaluating
historic correlations between CO2 and temperature.  Because the models are
built on an assumption that not only is temperature strongly correlated with
CO2, but that temperature is historically highly stable without this outside
anthropogenic forcing.  If there are problems with this assumed causation,
which we saw there are, then there in turn are major inherent problems with the
models themselves.   As climate scientist Syun-Ichi Akasofu of the
International Arctic Research Center at University of Alaska Fairbanks wrote:

The computers are "taught" that the temperature
rise during the last hundred years is due mostly to the greenhouse effect. If
the truth is that only about 10% of the present warming is caused by the
greenhouse effect, the computer code must be rewritten

Do Model Outputs Constitute Scientific Proof?

Remember what I said earlier:  The models produce the result that there
will be a lot of anthropogenic global warming in the future because they are
programmed to reach this result.  In the media, the models are used as a
sort of scientific money laundering scheme.  In money laundering, cash
from illegal origins (such as smuggling narcotics) is fed into a business that
then repays the money back to the criminal as a salary or consulting fee or
some other type of seemingly legitimate transaction.  The money he gets
back is exactly the same money, but instead of just appearing out of nowhere, it
now has a paper-trail and appears more legitimate.  The money has been
laundered.

In the same way, assumptions of dubious quality or certainty that presuppose
AGW beyond the bounds of anything we have see historically are plugged into the
models, and, shazam, the models say that there will be a lot of anthropogenic
global warming.  These dubious assumptions, which are pulled out of thin
air, are laundered by being passed through these complex black boxes we call
climate models and suddenly the results are somehow scientific proof of
AGW.  The quality hasn't changed, but the paper trail looks better, at
least in the press.  The assumptions begin as guesses of dubious quality
and come out laundered at "settled science."  Climate
Scientists Garth Paltridge wrote:

It needs to be understood that any reasonable
simulation even of present climate requires computer models to be tuned. They contain
parameters (that is, pieces of input information) whose numerical values are
selected primarily to give the right answer about today's climate rather than
because of some actual measurement. This was particularly so in the
mid-eighties. The problem with tuning is that it makes any prediction of
conditions different from those of the present far less believable. Even today
the disease of "tuneable parameters" is still rampant in climate
models, although fairly well hidden and not much spoken of in polite society.
The scientifically-inclined reader might try sometime asking a climate
researcher just how many such parameters there are in his or her latest model.
The reader will find there are apparently lots of reasons why such a question
is ridiculous, or if not ridiculous then irrelevant, and if not irrelevant then
unimportant. Certainly the enquirer will come away having been made to feel
foolish.

Econometrics and
CO2 Forecasts

The IPCC has never been able to choose a particular climate model it thinks
is best.  Instead, it aggregates ten or twelve of them and averages their
results, hoping that if there are errors in the climate models, they will
average out somehow (forgetting that systematic errors don't average out, as we
discussed earlier in the context of historic temperature
reconstructions).  The one thing the IPCC does do to bring some order to
all this is to establish baseline econometric and emissions scenarios for all
the teams to feed into the front end of their models.  That way, for a given
forecast case, they know variation in model output is due to differing
climate-related assumptions rather than differing economic assumptions.

But a funny thing happens when one tries to make an economic growth forecast
for 100-year periods, as the IPCC has: Very small changes in assumptions make
enormous differences.  Here is a simple example.  An economy that
grows by 3% per year will be 19x larger in 100 years.  However, if that
economy were to grow instead by 4% rather than 3%, it will be 51x larger in 100
years.  So a change in the growth rate by one percentage point yields a
final size nearly 2.7 times larger.   The same is true with
forecasting CO2 growth "“ a very small change in assumptions can lead to very
large differences in absolute production.

After release of the 3^rd IPCC report in 2001, researchers Ian
Castles, formerly the head of Australia's national office of statistics, and
David Henderson of the Westminster Business School and formerly the chief
economist of the OECD, decided to scrutinize
the IPCC's economic assumptions.  They found that the IPCC had made a
fundamental mistake in crafting their econometrics, one that caused all of
their economic growth estimates (and therefore estimates of CO2 production) to
be grossly overestimated.  Based on the IPCC assumptions, South Africa
ends up with a GDP per capita far in excess of the United States by the year
2100.  Incredibly, the IPCC numbers imply that Algeria, Argentina, Libya,
Turkey, and North Korea will all pass the US in per capita income by the end of
the century.

Beyond making it clear that there is an element of the absurd in the IPCC's
economic forecasting approach, these errors tend to inflate CO2 forecasts in
two ways.  First, CO2 forecasts are raised because, in the models, larger
economies produce more CO2.  Second, though, the models assume different
rates for CO2 production per unit of GDP for each country.  Most of the
countries the IPCC shows growing so fast "“ Algeria, South Africa, Libya, North
Korea, etc. "“ have lower than average CO2 efficiencies (i.e. higher than
average CO2 production per unit of GDP), so excess growth assumptions in these
countries has a disproportionate impact on projected CO2 emissions.  By
the way, it would be interesting to see if the IPCC is using marginal rather
than average rates.  For example, France has a very low average rate of
CO2 per unit of GDP because of its nukes, but its marginal growth is met mostly
with fossil fuels.

I can't say whether these same mistakes exist in the 2007 4^th
Assessment.  However, since the IPCC flatly rejected Castles and
Henderson's critique, it is likely the same methodology was used in 2007 as in
2001.  For example, here are the CO2 emissions forecasts from the 4^th
assessment "“ notice most all of them have a step-change increase in slope
between history and the future.  Just look at the jump across the dotted
line in lead case A1B, and several are even steeper.

So what does this mean?  Remember, small changes in growth rate make
big differences in end values.  For example, below are the IPCC fourth
assessment results for CO2 concentration.  If CO2 concentrations were to
increase at about the same rate as they are today, we would expect an end value
in 2100 of between 520 and 570 ppm, as opposed to the IPCC numbers below where
the projection mean is over 800 in 2100.  The difference is in large part
in the economic growth forecasts. 

Since it is not at all clear that the IPCC has improved its forecasting
methodology over the past years, it is instructive as one final exercise to go
back to the 1995 emissions scenarios in the 2^nd assessment.
Though the scale is hard to read, one thing is clear "“ only 10 years later we
are well below most of the forecasts, including the lead forecast is92a (this
over-forecasting has nothing to do with Kyoto, the treaty's impact has been
negligible, as will be discussed later).  One can be assured that if the
forecasts are already overstated after 10 years, they will be grossly
overstated in 100.

Climate Sensitivity
and the Role of Positive Feedbacks

As discussed earlier, climate sensitivity generally refers to the expected
reaction of global temperatures to a arbitrary change in atmospheric CO2
concentration.  In normal usage, it is usually stated as degrees Celsius
of global warming from a doubling in CO2 concentrations from pre-industrial
levels (approx 280 ppm to 560 ppm).  The IPCC and most AGW supporters put
this number at about 3.5 to 4.0 degrees C. 

But wait "“ earlier I said the number was probably more like 1.0C, and that
it was a diminishing return.  Why the difference?  Well, it has to do
with something called feedback effects.

Before I get into these, let's think about a climate sensitivity of 4
degrees C, just from a historical standpoint.  According to the IPCC, CO2
has increased by about 100ppm since 1880, which is about 36% of the way to a
doubling.  Over this same time period, global temperatures have increased
about 0.7C. Since not even the most aggressive AGW supporter will attribute all
of this rise to CO2 levels, let's be generous and credit CO2 with 0.5C.
So if we are 36% of the way to a doubling, and giving CO2 credit for 0.5
degrees, this implies that the sensitivity is probably not more than 1.4
degrees C.  And we only get a number this high if we assume a linear
relationship "“ remember that CO2 and temperature are a diminishing return
relation (chart at right), so future CO2 has less impact on temperature than
past CO2, so 1.4 would be at the high end.  In fact, using the logarithmic
relationship we saw before, 0.5 degrees over 36% of the doubling would imply a
sensitivity around 1.0.  So, based on history, we might expect at worst
another 0.5C from warming over the next century. 

Most AGW supporters would argue that the observed sensitivity over the last
30 years has been suppressed by dimming/sulfate aerosols.  However, to get
a sensitivity of 4.0, one would have to assume that without dimming, actual
warming would have been about 2.0C.  This means that for the number 4.0 to
be right,

1. Absolutely nothing else other than CO2 has been causing warming in the
last 50 years AND

2. Sulfate aerosols had to have suppressed 75% of the warming, or about
1.5C, numbers far larger than I have seen anyone suggest.  Remember that
the IPCC classifies our understanding of this cooling effect, if any, as "low"

But in fact, even the IPCC itself admits that its models assume higher
sensitivity than the historically observed sensitivity.  According to the
fourth IPCC report, a number of studies have tried to get at the sensitivity
historically (going back to periods where SO2 does not cloud the picture).
  Basically, their methodology is not much different in concept than
the back of the envelope calculations I made above.

These are shown in a) below, which shows a probability distribution of what
sensitivity is (IPCC4 p. 798). Note many of the highest probability values of
these studies are between 1 and 2.  Also note that since CO2 content is,
as the IPCC has argued, higher than it has been in recorded history, any
sensitivities calculated on historical data should be high vs. the sensitivity
going forward.  Now, note that graph c) shows how a number of the climate
models calculate sensitivity.  You can see that their most likely values
are consistently higher than any of the historical studies from actual
data.  This means that the climate models are essentially throwing out
historical experience and assuming that sensitivity is 1.5 to 2 times higher
going forward, despite the fact a diminishing return relationship says it
should be lower.

Sensitivity, based on History

Sensitivity that is built into the models  (Sorry, I still have no idea
what "constrained by climatology" means, but the text of the report makes it clear
that these sensitivities popped out of climate models

So how do these models get to such high sensitivities?  The answer, as
I have mentioned, is positive feedback.

Let me take a minute to discuss positive feedbacks.  This is something
I know a fair amount about, since my specialization at school in mechanical
engineering was in control theory and feedback processes.  Negative
feedback means that when you disturb an object or system in some way, forces
tend to counteract this disturbance.  Positive feedback means that the
forces at work tend to reinforce or magnify a disturbance.

You can think of negative feedback as a ball sitting in the bottom of a
bowl.  Flick the ball in any direction, and the sides of the bowl,
gravity, and friction will tend to bring the ball back to rest in the center of
the bowl.  Positive feedback is a ball balanced on the pointy tip of a
mountain.  Flick the ball, and it will start rolling faster and faster
down the mountain, and end up a long way away from where it started with only a
small initial flick.

Almost every process you can think of in nature operates by negative
feedback.  Roll a ball, and eventually friction and wind resistance bring
it to a stop.  There is a good reason for this.  Positive feedback
breeds instability, and processes that operate by positive feedback are
dangerous, and usually end up in extreme states.  These processes tend to
"run away."   I can illustrate this with an example:
Nuclear fission is a positive feedback process.  A high energy neutron
causes the fission reaction, which produces multiple high energy neutrons that
can cause more fission.  It is a runaway process, and it is dangerous and
unstable.  We should be happy there are not more positive feedback
processes on our planet.

Since negative feedback processes are much more common, and since positive
feedback processes almost never yield a stable system, scientists assume that
processes they meet are negative feedback until proven otherwise.  Except
in climate, it seems, where everyone assumes positive feedback is common.

In global warming models, water vapor plays a key role as both a positive
and a negative feedback loop to climate change.  Water vapor is a far more
powerful greenhouse gas than CO2, so its potential strength as a feedback
mechanism is high.  Water comes into play because CO2 driven warming will
put more water vapor in the atmosphere, because greater heat will vaporize more
water.  If this extra vapor shows up as more humid clear air, then this in
turn will cause more warming as the extra water vapor absorbs more energy and
accelerates warming.  However, if this extra water vapor shows up as
clouds, the cloud cover will tend to reflect energy back into space and retard
temperature growth. 

Which will happen?  Well, nobody knows.  The IPCC4 report admits
to not even knowing the sign of water's impact (e.g whether water is a
net positive or negative feedback) in these processes.  And this is just
one example of the many, many feedback loops that scientists are able to posit
but not prove. And climate scientists are coming up with numerous other
positive feedback loops.  As
one author put it:

Regardless, climate models are made interesting by
the inclusion of "positive feedbacks" (multiplier effects) so that a
small temperature increment expected from increasing atmospheric carbon dioxide
invokes large increases in water vapor, which seem to produce exponential
rather than logarithmic temperature response in the models. It appears to have
become something of a game to see who can add in the most creative feedback
mechanisms to produce the scariest warming scenarios from their models but
there remains no evidence the planet includes any such effects or behaves in a
similar manner.

Note that the majority of the warming in these models appears to be from
these feedback processes.  Though it is hard to pick it out exactly,
section 8.6 of the fourth IPCC report seems to imply these positive feedback
processes increase temperature 2 degrees for every one degree from CO2.
This explains how these models get from a sensitivity of CO2 alone of about 1.0
to 1.5 degrees to a sensitivity of 3.5 or more degrees "“ it's all in the
positive feedback.

So, is it reasonable to assume these feedback loops?
First, none have really been proven empirically, which does not of course
necessarily make them wrong. .  In our daily lives, we generally deal
with negative feedback:  inertia, wind resistance, friction are all negative
feedback processes.  If one knew nothing else, and had to guess if a
natural process was governed by negative or positive feedback, Occam's razor
would say bet on negative.   Also, we will observe in the next
section that when the models with these feedbacks were first run against
history, they produced far more warming than we have actually seen (remember
the analysis we started this section with "“ post-industrial warming implies
1-1.5 degrees sensitivity, not four).

Perhaps most damning is to ask, if this really is such a heavily positive
feedback process, what stops it?  Remember the chart from earlier (show
again at the right), showing the long-term relationship of CO2 and
warming.  Also remember that the data shows, and even AGW supporters
acknowledge, that temperature rises led CO2 rises by about 800 years.
Their explanation is that "something" caused the temperature to start
upwards.  This higher temperature, as it warmed the oceans, caused CO2 to
outgas from the oceans to the atmosphere.  Then, this new CO2 caused the
warming to increase further.  In other words, outgassing CO2 from the
oceans was a positive feedback to the initial temperature perturbation.
In turn, the IPCC argues there are various other positive feedbacks that
multiply the effect of the additional warming from the CO2.  This is
positive feedback layered on positive feedback.  It would be like barely
touching the accelerator and having the car start speeding out o f control.

So the question is, if global temperature is built on top of so many positive
feedbacks and multipliers, what stops temperature form rising once it
starts?  Why didn't the Earth become Venus in any of these events?
Because, for whatever else it means, the chart above is strong evidence that
temperature does not run away. 

I have seen two suggestions, neither of which is compelling.  The first
is that the oceans ran out of CO2 at some point.  But that makes no
sense.  We know that the oceans have far more CO2 than could ever be
liberated entirely to the atmosphere today, and besides,  the record above
seems to claim that CO2 in the atmosphere never really got above there it was
say in 1880.

The second suggestion is based on the diminishing return relationship of CO2
to temperature.  At some point, as I have emphasized many times, CO2's
ability to absorb infrared energy is saturated, and incremental quantities have
little effect.  But note in the IPCC chart above, CO2 on the long time
scale never gets as high as it is today.  If you argue that CO2's
absorption ability was saturated in earlier events, then you have to argue that
it is saturated today, and that incremental CO2 will have no further warming
effect, which AGW supporters are certainly NOT arguing.  Any theory based
on some unknown negative feedback has to deal with the same problem:  If
one argues that this negative feedback took over at the temperature peaks (in
black) doesn't one also have to argue that it should be taking over now at our
current temperature peak?  The pro-AGW argument seems to depend on an assumption
of negative feedbacks in the past that for some reason can't be expected to
operate now or in the future.  Why?

In fact, we really have not seen any evidence historically of these positive
feedback multipliers.  As I demonstrated at the beginning of this chapter,
even assigning as much as 0.5C of the 20^th century temperature
increase to CO2 only implies a sensitivity just over 1.0, which is about what
we would expect from CO2 alone with no feedbacks.  This is at the heart of
problems with AGW theory "“ There is no evidence that climate sensitivity to CO2
is anywhere near large enough to justify the scary scenarios spun by AGW
supporters nor to justify the draconian abatement policies they advocate.

My tendency is to conclude that in fact, positive feedbacks do not dominate
climate, just as they do not dominate any long-term stable system.  Yes,
certain effects can reasonably be said to amplify warming (ice albedo is
probably one of them) but there must exist negative feedbacks that tend to damp
out temperature movements.  Climate models will never be credible, and
will always overshoot, until they start building in these offsetting forcings.

Climate Models had
to be aggressively tweaked to match history

A funny thing happened when they first started running climate
models with high CO2 sensitivities in them against history:  The models
grossly over-predicted historic warming.  Again, remember our previous
analysis "“ historical warming implies a climate sensitivity between 1 and
1.5.  It is hard to make a model based on a 3.5 or higher sensitivity fit
that history.  So it is no surprise that one can see in the IPCC chart
below that the main model cases are already diverging in the first five years
of the forecast period from reality, just like the Superbowl predictors of the
stock market failed four years in a row.  If the models are already high
by 0.05 degree after five years, how much will they overshoot reality over 100
years?

In a large sense, this is why the global climate community has latched onto
the global dimming / aerosols hypothesis so quickly and so strongly.  The
possible presence of a man-made cooling element in the last half of the 20^th
century, even one that the IPCC fourth report ranks our understanding of as
"low," gives modelers a valuable way to explain why their models are
overstating history.  The aerosols hypothesis is valuable for two reasons:

· Since
SO2 is prevalent today, but is expected to go down in the future, it allows
modelers to forecast much higher warming and climate sensitivity in the future
than has been observed in the past.

· Our
very lack of understanding of the amount, if any, of such aerosol cooling is
actually an advantage, because it allows modelers to set the value of such
cooling at whatever value they need to make their models work

I know the last statement seems unfair, but in reading the IPCC and other
reports, it appears to me that aerosol cooling values are set in exactly this
way "“ as what we used to call a "plug" figure between actual temperatures and
model output.  While this may seem a chancy and fairly circular reasoning,
it makes sense for scientists because they trust their models.  They
really believe the outputs are correct, such that any deviation is not
attributed to their assumptions about CO2 or climate sensitivity, but to other
man-made effects.

But sulfates are not the only plug being used to try to make high
sensitivity models match a lower sensitivity past.  You can see this in
the diagram below from the fourth IPCC report.  This is their summary of
how their refined and tweaked models match history. 

The blue band is without anthropogenic effects.
The pink band is with anthropogenic effects, including warming CO2 and cooling
aerosols.  The black line is measured temperatures (smoothed out of
course).

You can see the pink band which represents the models with anthropogenic
effects really seems to be a lovely fit, which should make us all
nervous.  Climate is way too chaotic a beast to be able to model this
tightly.   In fact, given uncertainties and error bars on our
historical temperature measurements, climate scientists are probably trumpeting
a perfect fit here to the wrong data.  I am reminded again of a beautiful
model for presidential election results with a perfect multi-decadal fit based
on the outcome of NFL football games. 

But ignoring this suspiciously nice fit, take a look at the blue bar.
This is what the IPCC models think the climate would be doing without
anthropogenic effects (both warming CO2 and cooling sulfates, for
example).  With the peaked shape (which should actually be even more
pronounced if they had followed the mid-century temperature peak to its max)
they are saying there is some natural effect that is warming things until 1950
and then turns off and starts cooling, coincidently in the exact same year
that anthropogenic effects start taking off.  I challenge you to read
the IPCC assessment, all thousand or so pages, and find anywhere in that paper
where someone dares to say exactly what this natural effect was, or why it
turned off exactly in 1950. 

The reality is that this natural effect is another plug.  There is no
actual empirical data to back up the blue line (in fact, as we will see in the
alternate theories section, there is good empirical data that this blue band is
wrong).  Basically, climate scientists ran their models against history,
and found that even with their SO2 plug, they still didn't match well "“ they
were underestimating early century warming and over-estimating late century
warming.  Remember that the scientists believe their models and their
assumptions about a strong CO2 effect, so they have modeled the non-anthropogenic
effect by running their models, tuning them to historical actuals, and then
backing out the anthropogenic forcings to see what is left.  What is left,
the plug figure, is the blue line.

Already, the models used by the IPCC tend to overestimate past warming even
if all past warming is attributable to anthropogenic causes.  If
anthropogenic effects explain only a fraction of past warming, then the current
models are vastly overstated, good for stampeding the populous into otherwise
unpopular political control over the economy, but of diminished scientific
value.

The note I will leave you with is this:  Do not gain false confidence
in the global climate models when they show you charts that their outputs run
backwards closely match history.  This is an entirely circular argument,
because the models have been built, indeed forced, to match history, with
substantial plug figures added like SO2 effects and non-anthropogenic climate
trends, effects for which there are no empirical numbers.

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

The open comment thread for this paper can be found here. 

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

Solar Irradiance

If you walked into a room and found that it was too hot,
would you, as a first step:

1. Measure the air to find anomalies in the mix of gasses
2. Count the number of people in the room, to assess the effect
        of body heat on the room's temperature
3. Check the thermostat on the furnace

If you answered #3, sorry, but you can't join the
IPCC.  If you really want to irritate an AGW supporter, ask about the
sun.  To AGW supporters, only a Luddite would check the sun's output when
they could instead be obsessing over the increase in CO2 by 0.009% of the
atmosphere.

When they looked at the problem, the IPCC decided that over
the last 50 years, the sun has been irrelevant to warming.  Note that the
blue band in this chart (described in more detail in the last section), the
IPCC thinks that without man, the world would have cooled over the last 50
years:

Further, when they detailed different climate forcings, the
forcing from changing solar irradiance was a trivial rounding error (though
they had the good grace to mark their understanding of this as "low") meaning
the sun has very little effect vs. what the sun had in 1850 (in the Little Ice
Age!)

But it turns out, interestingly, that solar irradiance may be close to its
highest point in centuries.  Al Gore says that current global temperatures
are the highest they have been in 1000 years.  A new study by
the Institute of Astronomy in Zurich says that the "sun is more active now
than it has been at anytime in the previous 1,000 years."  Related?

Sunspots have been monitored on the Sun since 1610,
shortly after the invention of the telescope. They provide the longest-running direct
measurement of our star's activity.

The variation in sunspot numbers has revealed the
Sun's 11-year cycle of activity as well as other, longer-term changes.

In particular, it has been noted that between about
1645 and 1715, few sunspots were seen on the Sun's surface.

This period is called the Maunder Minimum after the
English astronomer who studied it.

It coincided with a spell of prolonged cold weather
often referred to as the "Little Ice Age". Solar scientists strongly
suspect there is a link between the two events - but the exact mechanism
remains elusive....

But the most striking feature, he says, is that
looking at the past 1,150 years the Sun has never been as active as it has been
during the past 60 years.

Over the past few hundred years, there has been a
steady increase in the numbers of sunspots, a trend that has accelerated in the
past century, just at the time when the Earth has been getting warmer.

The data suggests that changing solar activity is
influencing in some way the global climate causing the world to get warmer.

We can look at solar output over large time frames by
looking at the production of carbon-14 (less is produced in years of high solar
activity, and vice versa).  The analysis below used the ratio of oxygen
isotopes in the stalagmites to estimate the water temperature at the time they
were formed.  The result is an interesting correlation between solar
activity and a global temperature proxy over a long time-scale (Graph from Neff et al., 2001):

Over the last 1000 years, we see that (again using a
reversed scale of C14 as a proxy) solar activity is highly correlated with long
term temperature trends (I have used the pre-Mann chart, because while it may
over-emphasize the Medieval Warm Period, I still think such a period existed).

               
Solar Output
Anomaly                                                                      

              Temperature Anomaly

Look at the following reconstruction data by Judith Lean of
the Naval Research Library and charted from her data at NOAA by Junkscience.com
shows that interestingly, the sun's output does appear to be higher today than
they have been in many, perhaps hundreds of years

Would such increased activity be expected to result in
higher Earth temperatures?  I don't know, and there are some issues one
has to be careful with on this chart.  Most importantly the scaling:
While the shape of the curve looks a lot like the temperature trend over the
last 400 years, note that the entire variation from the low to the high point
is only about 0.25% "“ the scaling makes it look more dramatic.  Of course,
the same could be said for global temperature, where a half degree C
temperature increase on an absolute Kelvin scale would only be about 0.17%, so
an argument can be made that on a percentage basis, this change in irradiance
is about the same order of magnitude as our change in temperature.  A more
sophisticated comparison might say that since black body radiation is related
to absolute temperature to the fourth power, .25% increase in irradiance would
be expected to heat the Earth by .06%.

The chart on the above left compares the recent temperature
anomaly to solar irradiance, while the chart on the right compares it to CO2
concentrations.  Neither is a beautiful fit (and one may have to include
aerosols in either scenario to account for 1970's cooling) but solar irradiance
seems at least as good as that of CO2.  Remember, the IPCC shows
the world cooling due to solar effects during the same time the red solar
irradiance line is peaking. 

Recently Alexander et. al. in have done some very comprehensive
work relating solar irradiance and rainfall.  The study posits that one of
the reasons for less than perfect fit of sunspot and irradiance data with
temperature is that the Sun actually works on a 21 year cycle when the sunspot
cycle is combined with the cyclical wobble of the Suns motion through
space.  The study concluded:

The
Intergovernmental Panel on Climate Change (IPCC) (2001) dismisses the view that
solar activity has a meaningful influence on global climate. The basis for this
view is that variations in the receipt of solar activity are too small to
account for variations in the climatic responses. These variations were
determined from satellite and other observations. What the IPCC scientists
failed to appreciate is that changes in the level of solar radiation received
on earth are amenable to precise calculation. The variations are well in excess
of the IPCC value of +0,3 Wm"“2 quoted earlier.

One of the interesting things about solar output is that, if
it is really higher, we should see effects on other planets, not just on
Earth.  And, in fact, a lot of evidence has been pouring in over the last
5 years from astronomers (not climate guys) that the rest of the solar system
has been warming dramatically.

Take
Mars, for example.  Mar's ice caps have been melting and diminishing
since NASA's Mars Global Surveyor and Odyssey started to measure them around
2002. 

Changes in the red spot on Jupiter
seem to be a sign of warming temperatures.  And Neptunes moon Triton is
warming.  We have to be careful with how we draw conclusions on these
outer planets, since their "year" is so long, seasonal changes can last
decades. 

And
on Neptune:

As seen in Figure 1, Neptune has been getting
brighter since around 1980; furthermore, infrared measurements of the planet
since 1980 show that the planet has been warming steadily from 1980 to 2004. As
they say on Neptune, global warming has become an inconvenient truth. But with
no one to blame, Hammel and Lockwood explored how variations in the output of
the Sun might control variations in the brightness of Neptune.

Figure 1 (a) represents the corrected visible light from Neptune from 1950 to
2006; (b) shows the temperature anomalies of the Earth; (c) shows the total
solar irradiance as a percent variation by year; (d) shows the ultraviolet emission
from the Sun (Source: Hammel and Lockwood (2007)).

What would seem so simple statistically is
complicated by the degrees of freedom in the various time series which is
related to the serial correlation in the data (e.g., next year's value is
highly dependent on this year's value). Nonetheless, they find that the
correlation coefficient between solar irradiance and Neptune's brightness is
near 0.90 (1.00 is perfect). The same relationship is found between the Earth's
temperature anomalies and the solar output. Hammel and Lockwood note "In other
words, the Earth temperature values are as well correlated with solar
irradiance (r = 0.89) as they are with Neptune's blue brightness (|r| >
0.90), assuming a 10-year lag of the Neptune values." The temporal lag is
needed to account for the large mass of Neptune that would require years to
adjust to any changes in solar output.

Hammel and Lockwood conclude that "In summary, if
Neptune's atmosphere is indeed responding to some variation in solar activity
in a manner similar to that of the Earth albeit with a temporal lag" then
"Neptune may provide an independent (and extraterrestrial) locale for studies
of solar effects on planetary atmospheres."

More on the sun's
variance and climate change here.

Cosmic Rays

One of the problems with irradiance as a driver for climate
change is that though the changes seem to be fairly well correlated with the
temperature anomaly, many scientists think the magnitude is too small to
totally account for temperature changes.  It is ironic that AGW supporters
use this as a refutation of the sun's effect, since they have exactly the same
problem with CO2, and must posit huge positive feedback loops to justify their
forecasts. 

A second, newer theory has emerged as to a potential second
warming effect of solar output.  To understand it, we have to start with
clouds.  For those that don't live in a hot climate like I do here in
Phoenix, I will give everyone a bit of background "“ clouds cool things
off.  Ok, as with everything in climate, things are actually far more
complicated "“ high clouds can sometimes cause warming, and nighttime clouds can
actually slow cooling.  Never-the-less, in general, cloudcover cools things
off by blocking out and reflecting the sun's energy.

Clouds are in fact such a strong cooling force that is has
been estimated by several sources (Theodor Landscheidt, 1998) that having
clouds cover 1% more of the Earth's surface would cancel the heating effect of
a doubling of CO2.   In fact, it was one of my criticisms earlier
that AGW theory seems overly intent on finding positive feedback loops, while
not considering negative feedbacks seriously enough "“ one such potential
negative feedback is that on a warmer Earth, more water is evaporated into
clouds, in turn cooling things back off.

But recently, an interesting new theory on cloud formation
has emerged.  In short, it holds that cosmic rays, which are the high
energy particles that arrive at Earth from supernovas, spur cloud formation by
ionizing air molecules that act as seeds for water condensation and cloud
formation.  This sounds wild, but really no wilder than warming by a gas
(CO2) that makes up a near trivial portion of the atmosphere.  Like CO2 warming,
this effect has been observed in various laboratory chambers.  But is it
really a measurable driver of climate?

Henrik
Svensmark and Eigil Fris-Christensen looked at historic data on cloud cover
and cosmic ray incidence, from various measuring points.  Their data was
extended and refined by Shiva in 2005.

Cosmic rays
vs. CO2 detailed

So what changes cosmic ray flux to the Earth?  The
biggest influence is the sun.  When the sun's output is high, cosmic rays are
prevented from hitting the Earth, and vice versa.  So high solar activity
corresponds to low cosmic ray flux and therefore lower cloud formation and
higher temperatures. 

While the link between solar irradiance levels and warming
is pretty straight forward, the cosmic ray cloud formation proposition is still
in its infancy.  Those of us who criticize AGW supporters for running past
the evidence on CO2 should not make the same mistake on cosmic rays, and movies
such as The Global Warming Swindle have gone too far in portraying this
alternate theory as fact.

Man's Land Use

Recently, Roger Pielke has done a substantial amount of
research on a different type of anthropogenic forcing.  Specifically, he
has hypothesized that man's changing patterns of land use can be a substantial
driver of regional climate, including temperature and even more particularly,
precipitation.   For example, clearing relatively dry land and
replacing it with irrigated agriculture substantially changes to the local heat
balance,  not the least by increasing humidity.  Dr. Pielke explains
summarizes the consequences on his web site:

Humans are significantly altering
the global climate, but in a variety of diverse ways beyond the radiative
effect of carbon dioxide. The IPCC assessments have been too conservative in
recognizing the importance of these human climate forcings as they alter
regional and global climate. These assessments have also not communicated the
inability of the models to accurately forecast the spread of possibilities of
future climate. The forecasts, therefore, do not provide any skill in
quantifying the impact of different mitigation strategies on the actual climate
response
that would occur.

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

The open comment thread for this paper can be found here. 

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

As stated in the introduction, the purpose of this paper has
not been to provide a balanced portrayal of Anthropogenic Global Warming (AGW) theory; its purpose instead is to
provide a comprehensive overview of skeptic's concerns with AGW theory.
However, the issues raised here are not necessarily new, and AGW supporters
have attempted to address many of them. 

The New
Scientist, a fairly strong and reliable voice for advocacy of anthropogenic
global warming theory, recently published its response to what it calls 26
myths about global warming, many of these "myths" being correlated loosely with
skeptics concerns about AGW theory as outlined in this paper.  Walking
through their points seems a reasonable way to entertain a rebuttal to the
skeptic's position.  Each of these has a link to the New Scientist article
in question.  I have tried to summarize the position with a quote, shown
in italics.  My response to each then follows.

Before I get into these 20 myths, note that many of the key
skeptic's questions are neatly avoided.   While the magazine gives
itself certain softball questions, it does not attempt to take on skeptics
questions such as:

• Isn't warming from CO2 a diminishing return, such that each 10ppm of CO2
  has less warming effect than the last 10 ppm?
• Isn't warming from CO2 asymptotic, such that total warming from CO2 is
  capped?
• Isn't 2/3 or more of the future warming in IPCC forecasts due to
  positive feedback effects that tend to be rare in stable systems and that even
  the IPCC admits are poorly understood?
• Aren't there a lot of problems with ground-based temperature measurements?
• Aren't the historical proxies for temperature diverging from
  measurements, such that the IPCC actually dropped many of the recent proxy
  measurements to hide this result?

There are many others, but we can get at them tangentially
through dealing with the 20 "myths" below

"¢ Human
CO₂ emissions are too tiny to matter

So what's going on? It is true that human
emissions of CO₂ are small compared with natural sources. But the
fact that CO₂ levels have remained steady until very recently shows
that natural emissions are usually balanced by natural absorptions. Now
slightly more CO₂ must be entering the atmosphere than is being
soaked up by carbon "sinks".

Though I do know that some skeptics will claim that man can't be changing
world CO2 levels, I don't believe I even tried to make that claim in this paper.

The more salient point in
asking whether human CO2 emissions are too tiny to matter is to ask whether the
change in composition of the atmosphere of 0.009% by human activities is
substantial enough to affect world climate in any important way, particularly
when the portion being increased, CO2, is a relatively weak greenhouse gas vs.
other portions.

"¢ We
can't do anything about climate change

It is true that the action taken
so far, such as the Kyoto Protocol, will only have a marginal effect. The
protocol's authors have always described it as a first step. But even before it
came into effect in 2005, the protocol has triggered some profound thinking
among governments, corporations and citizens about their carbon footprint and
how to reduce it. Industrialized countries such as the UK are planning for
emissions reductions of 60% or more by mid-century.

This is a bit of a straw man.  Certainly to the extent
that man is causing climate change, men with enough will can do something about
it.  The question is whether the costs justify the avoided change "“ this
is a question that I have addressed sufficiently and won't revisit here.
However, I would like to comment on this:

We may find that once the
process has begun, the world loses its addiction to carbon fuels surprisingly quickly.
Natural scientists fear "tipping points" in the climate system. But there are
also tipping points in social, economic and political systems. Once under way,
things can happen fast"¦

This is a statement to which I both agree and disagree.  I am a technological
optimist, and so generally accept that world-changing technologies will
continue to spring from man's mind, and that the introduction of these changes
can be fast and their impact dramatic.  The only reason that I am a tad
skeptical about this statement is that the vast majority of strong AGW
adherents are technology pessimists, so it would be uncharacteristic for them
to take such a position.  Absent unimagined new technologies, change of
the type AGW supporters are hoping for is actually not a positive
feedback process as implied in this statement. Why is it that climate
scientists see so many positive feedback processes, when these are actually so
rare? In fact, most investment decisions, for example investments to reduce CO2
emissions, follow a diminishing return relationship.  Early investors
capture the low-hanging fruit, while each successive wave of investment offers
a lower return (here, in CO2 reduction) for each incremental dollar invested.

"¢ The
'hockey stick' graph has been proven wrong

Most researchers would agree that while the
original hockey stick can "“ and has "“ been improved in a number of ways, it was
not far off the mark. Most later temperature reconstructions fall within the
error bars of the original hockey stick. Some show far more variability leading
up to the 20^th century than the hockey stick, but none suggest that
it has been warmer at any time in the past 1000 years than in the last part of
the 20^th century.

No one statement by AGW supporters would do more to build my confidence in
their findings than to actually have someone say "the Mann hockey stick was a
deeply flawed analysis, and we have taken great pains to make sure the flaws identified
in Mann are not present in other historical reconstructions."  However,
when I see the statement above, I am left to wonder if any of the flaws in Mann
have actually been corrected in other works, or if systematic errors still
exist.  Since AGW supporters refuse to acknowledge flaws in Mann, it is
almost certain that these flaws still exist in the other analyses (therefore
making it unsurprising that new analyses show roughly the same results).
Remember that Mann was replaced by Biffra as lead author of this section of the
Fourth IPCC report, and it was Biffra who dropped 20-30 years of recent data
from his historical reconstruction when it did not show the result that he
wanted it to.

"¢ Chaotic
systems are not predictable

Getting reasonably accurate
predictions is a matter of choosing the right timescale: days in the case of
weather, decades in the case of climate.

Climate scientists sometimes
refer to the effects of chaos as intrinsic or unforced variability: the
unpredictable changes that arise from the dynamic interactions between the
oceans and atmosphere rather than being a result of "forcings" such
as changes in solar irradiance or greenhouse gases.

The crucial point is that
unforced variability occurs within a relatively narrow range. It is constrained
by the major factors influencing climate: it might make some winters bit a
warmer, for instance, but it cannot make winters warmer than summers

There are systems people who would both agree and disagree
with this statement.  The real study of chaotic systems is barely older
than the study of global warming, and most mathematicians would say that the
issue of long-term predictability of macro trends in chaotic systems is not
settled science.

However, one issue the statement overlooks is that even if
chaotic systems have some long-term order, at least when "viewed from a
distance," this does not mean that the drivers of those long-term trends can be
discerned by those of us standing in the chaos.  So while it may be
theoretically possible to predict long-scale climate changes, it may still be
impossible to discern the true drivers of these climate systems amidst the
chaos, making the long-term prediction problem moot.

Remember, no one has a thermometer that provides two readings "“ temperature
due to "natural" causes and temperature due to man-made forcings. 
The only argument one can make outside of a laboratory is to try to correlate
temperature changes to certain other variables, like CO2 level.  But in a
chaotic system, when thousands of variables may matter, and there are all kinds
of cross-dependencies between variables, definitively showing direct
correlation, much less causation, is very hard, possibly impossible. 
Remember, outside lab experiments, climate scientists main argument that CO2 is
causing current warming is "We have checked everything else it possibly could
be, and it wasn't those things, so it must be CO2."  In a chaotic system,
such a statement borders on hubris.

"¢ We
can't trust computer models of climate

Climate is average weather, and it can vary unpredictably
only within the limits set by major influences like the Sun and levels of
greenhouse gases in the atmosphere. We might not be able to say whether it will
rain at noon in a week's time, but we can be confident that the summers will be
hotter than winters for as long as the Earth's axis remains tilted.

The validity of models can be tested against
climate history. If they can predict the past (which the best models are pretty
good at) they are probably on the right track for predicting the future "“ and
indeed have successfully done so.

I hope that if you have learned anything from this paper, you already know
how to refute the statement above.  Climate models match history because
they have been tuned and tweaked and overridden to do so.  The fact that
they then can reproduce history is meaningless.  Even more, you should run
away quickly from anyone who makes this statement, because they are either
ignorant of what they are talking about or they are trying to sell you the
Brooklyn Bridge.

Finally, the claim is sometimes
made that if computer models were any good, people would be using them to
predict the stock market. Well, they are!

A lot of trading in the
financial markets is already carried out by computers. Many base their
decisions on fairly simple algorithms designed to exploit tiny profit margins,
but others rely on more sophisticated long-term models.

Sorry, but this is a facile and ignorant mis-interpretation of what
financial models are doing.  Yes, people are running long-term financial
models as part of a trading strategy, but these models feed into very
short-term trading decisions.  If you looked at the output from these long-term
models, you would see that they are changing constantly as new data flows
in.  There is an old joke about two campers who see a bear growling at
them.  One of them starts putting his tennis shoes on.  The other one
says to him "Why are you putting your shoes on?  You can't outrun that
bear."   His friend replied "I don't have to outrun the bear.  I
just have to outrun you."  Traders' long-term models work the same.
They don't actually expect them to be right, they just want them to be better,
based on current conditions, than other traders' models, then they can make
money.

"¢ They
predicted global cooling in the 1970s

Indeed they did"¦. However, Schneider soon
realised he had overestimated the cooling effect of aerosol pollution and
underestimated the effect of CO₂, meaning warming was more likely
than cooling in the long run"¦.

The calls for action to prevent further
human-induced global warming, by contrast, are based on an enormous body of
research by thousands of scientists over more than a century that has been
subjected to intense "“ and sometimes ferocious "“ scrutiny. According to the
latest IPCC report, it is more than
90% certain that the world is already warming as a result of human activity

We have already dealt with aerosols, and unlike many skeptics I have not
really held the 1970's global cooling panic against the climate
community.  The last paragraph is just circular.  Saying the IPCC is
90% sure does not answer the arguments about what skeptics feel the IPCC is
ignoring.

"¢ It's
been far warmer in the past, what's the big deal?

First of all, it is worth bearing in mind that
any data on global temperatures before about 150 years ago is an estimate, a
reconstruction based on second-hand evidence such as ice cores and isotopic
ratios. The evidence becomes sparser the further back we look, and its
interpretation often involves a set of assumptions. In other words, a fair
amount of guesswork.

This is hilarious.  What happened to their confidence in Mann and
1000-year temperature reconstructions just a few myths back?  But to
continue, the answer is basically yes, but:

The important question is what
is causing the current, rapid warming? We cannot dismiss it as natural
variation just because the planet has been warmer at various times in the past.
Many studies suggest it can only be explained by taking into account human
activity.

Nor does the fact that it has
been warmer in the past mean that future warming is nothing to worry about. The
sea level has been tens of metres higher during past warm periods, enough to
submerge most major cities around the world.

Here is why it matters "“ beyond the laboratory evidence of the greenhouse
effect, which tells us merely that there is an affect and not how strong it is,
the main evidence cited by AGW supporters for current warming being man-made is
to try to show that current warming is somehow unprecedented, and therefore
unlikely to be natural.  So it is odd here that AGW supporters simply
shrug their shoulders here and say that it is not important that current
warming be unprecedented.

"¢ It's
too cold where I live - warming will be great

This does not sound too bad, and for many people
it won't be. Wealthy individuals and countries will be able to adapt to most
short-term changes, whether it means buying an air conditioner or switching to
crops better suited to the changing climate. Rainfall will fall in
mid-latitudes but rise in high latitudes, and initially agricultural yields
will probably.  Some regions will suffer, though. Africa could be hardest
hit, with yields predicted to halve in some countries as early as 2020.

As global temperature climbs to 3°C above
present levels - which is likely
to happen before the end of this century if greenhouse emissions continue
unabated - the consequences will become increasingly severe. More than a third
of species face extinction. Agricultural yields will start to fall in many
parts of the world. Millions of people will be at risk from coastal flooding.
Heatwaves, droughts, floods and wildfires will take an ever greater toll.

I hope readers will accept that I am not exaggerating or constructing straw
men when I talk about the dire predictions by AGW supporters.  There is
nothing here that we have not dealt with earlier, except perhaps the
rainfall.  Of late, AGW supporters seem to have shifted to rainfall
(rather than sea level rise) as their lead scary topic.  Note, however,
that even the IPCC admits that it and all of its modelers really do not
understand (even a little bit) the effect of global warming on rainfall and
drought.  Logic says that with more water evaporated, while global warming
may cause now local draughts, overall rainfall should increase.  I would
bet any amount of money that lower economic growth due to aggressive CO2 abatement
will have a far more deleterious effect on worldwide agricultural yields than
global warming.

"¢ Global
warming is down to the Sun, not humans

So what role, if any, have solar fluctuations
had in recent temperature changes? While we can work out how Earth's orbit has
changed going back many millions of years, we have no first-hand record of the
changes in solar output associated with sunspots before the 20^th century.

It is true that sunspot records go back to the
17^th century, but sunspots actually block the Sun's radiation. It is
the smaller bright spots (faculae) that increase the Sun's output and these
were not recorded until more recently. The correlation between sunspots and
bright faculae is not perfect, so estimates of solar activity based on sunspot
records may be out by as much as 30%.

The other method of working out past solar
activity is to measure levels of carbon-14 and beryllium-10 in tree rings and
ice cores. These isotopes are formed when cosmic rays hit the atmosphere, and
higher sunspot activity is associated with increases in the solar wind that
deflect more galactic cosmic rays away from Earth. Yet again, though, the
correlation is not perfect. What is more, recent evidence suggests that the
deposition of beryllium-10 can
be affected by climate changes, making it even less reliable as a measure
of past solar activity.

This is again a pretty hilarious statement.  One could easily argue
that temperature and CO2 proxies have at least as much
uncertainty.  One wonders why AGW advocates do not seem as concerned about
the errors in the proxies they hold dear.  But anyway, to continue:

But even if solar forcing in the past was more
important than this estimate suggests, as some scientists think, there is no
correlation between solar activity and the strong warming during the past 40
years. Claims that this is the case have not stood up to scrutiny (pdf document).

Direct measurements of solar output since 1978
show a steady rise and fall over the 11-year sunspot cycle, but no upwards or downward trend .

Similarly, there is no trend in direct
measurements of the Sun's ultraviolet output and in cosmic rays. So for the
period for which we have direct, reliable records, the Earth has warmed
dramatically even though there has been no corresponding rise in any kind of
solar activity.

This is another you-study-my-study pissing match.  I am happy to admit
that our knowledge of the sun's changing impact on climate is poor, and that it
is hard to separate out this one effect in a chaotic system.  I refuse to
fall into the same scientific hubris as AGW supporters.  However, those
who think the sun has some contribution to warming are buttressed by the
knowledge that they are working with the main driver of climate, rather than a
secondary variable.

"¢ It's
all down to cosmic rays

There is no convincing evidence
that cosmic rays are a major factor determining cloud cover. The ionising of
air by cosmic rays will impart an electric charge to aerosols, which in theory
could encourage them to clump together to form particles large enough for cloud
droplets to form around, called "cloud condensation nuclei".

But cloud physicists say it has
yet to be shown that such clumping occurs. And even if it does, it seems
far-fetched to expect any great effect on the amount of clouds in the atmosphere.
Most of the atmosphere, even relatively clean marine air, has plenty of cloud
condensation nuclei already.

A series of attempts by
Svensmark to show an effect have come unstuck. Initially, Svensmark claimed
there was a correlation between cosmic ray intensity and satellite measurements
of total cloud cover since the 1980s "“ yet a correlation does not prove cause
and effect. It could equally well reflect changes in solar irradiance, which
inversely correlate with cosmic ray intensity.

I am starting to notice a trend here of making statements about competing
that could be applied equally well to AGW theory.  And what about all
those points they made above, reminding us over and over that CO2 greenhouse
theory works in the lab.  Now the lab is not good enough?

However, I would accept that the cosmic ray theory is pretty undeveloped and
not acceptably proven.  It has had a number of fits and starts.  Just
like CO2 greenhouse theory, the cosmic ray effect on climate can be reproduced
in the lab, but it is really hard to parse out its effects in the chaotic
climate.

"¢ CO₂
isn't the most important greenhouse gas

At some of these overlaps, the
atmosphere already absorbs 100% of radiation, meaning that adding more
greenhouse gases cannot increase absorption at these specific frequencies. For
other frequencies, only a small proportion is currently absorbed, so higher
levels of greenhouse gases do make a difference.

This means that when it comes to
the greenhouse effect, two plus two does not equal four.

Wow!  An AGW supporter actually said this in public.  This is to
our point that there is a diminishing return from incremental CO2 in the
atmosphere.  Of course, they say this in the context of trying to show why
water isn't as important as it might seem, but still, it's there

But the overall quantities of these other gases
are tiny. Even allowing for the relative strength of the effects, CO₂
is still responsible for two-thirds
of the additional warming caused by all the greenhouse gases emitted as a
result of human activity.

Water vapour will play a huge role in the
centuries to come, though. Climate models, backed by satellite
measurements, suggest that the amount of water vapour in the upper
troposphere (about 5 to 10 kilometres up) will double by the end of this
century as temperatures rise.

This will result in roughly twice as much
warming than if water vapour remained constant. Changes in clouds could lead to
even greater amplification of the warming or reduce it "“ there is great uncertainty
about this. What is certain is that, in the jargon of climate science, water
vapour is a feedback, but not a forcing.

Again, I am not getting into this, we covered it plenty in the paper.
When they say "CO2 is still responsible for two-thirds of the additional
warming" (and remember this is an output of their models, not any other
analysis)  what they really mean is that "our models that were programmed
to have CO2 drive the climate show that CO2 drives the climate."
Note that in a three paragraph answer about the effect of water vapor as
a climate feedback, only three words "“ "or reduce it" "“ acknowledge that it
might actually have a negative feedback effect, despite the fact that even the
IPCC includes cloud cover as a negative feedback.  They just don't want to
admit a negative feedback might even exist.

"¢ The
lower atmosphere is cooling, not warming

One study in Science
revealed errors in the way satellite data had been collected and interpreted.
For instance, the orbit of satellites gradually slows, which has to be taken
into account because it affects the time of day at which temperature recording
are taken. This problem was always recognised, but the corrections were given
the wrong sign (negative instead positive and vice versa).

A second study, also
in Science, looked at the weather balloon data. Measurements of the air
temperature during the day can be skewed if the instruments are heated by
sunlight. Over the years the makers of weather balloons had come up with better
methods of preventing or correcting for this effect, but because no one had
taken these improvements into account, the more accurate measurements appeared
to show daytime temperatures getting cooler.

The corrected temperature records show that
tropospheric temperatures are indeed rising at roughly the same rate as surface
temperatures. Or, as a 2006 report by the US Climate Change Science Program (pdf) puts
it: "For recent decades, all current atmospheric data sets now show
global-average warming that is similar to the surface warming." This one
appears settled.

There is still some ambiguity in the tropics,
where most measurements show the surface warming faster than the upper
troposphere, whereas the models predict faster warming of the atmosphere.
However, this is a minor discrepancy compared with cooling of the entire
troposphere and could just be due to the errors of margin inherent in both the
observations and the models.

First, observe absolutely ruthless efforts to apply corrections and
adjustments to any measurement that does not fit their theory, while blithely
accepting the surface temperature measurements that we showed can be really
unreliable.  Given the choice of focusing on managing satellite
temperatures up or surface temperature down, you can see which they
chose.   Second, note that this is another narrow one study
conclusion.  AGW supporters frequently cite single studies (conducted by
AGW supporters) that overturn skeptics arguments as having "settled" the
issue.  There are still many reasons to think that troposphere temperature
increases are less than surface increases.  Finally, even temperature
increases that were the same between the surface and the troposphere would be a
real problem for AGW theory.  The authors here act like this
surface-troposphere issue is a minor deal, but in fact if AGW theory is right,
the troposphere has to warm more, because that is where the extra heat
is being absorbed.  This is not at all settled. 

"¢ Antarctica
is getting cooler, not warmer, disproving global warming

It is clear that the Antarctic Peninsula, which juts
out from the mainland of Antarctica towards South America, has warmed
significantly. The continent's interior was thought to have warmed too, but in
2002 a new analysis of
records from 1966 to 2000 concluded that it has cooled overall"¦.

Climate models do not predict an evenly spread
warming of the whole planet: changes in wind patterns and ocean currents can
change the distribution of heat, leading to some parts warming much faster than
average, while others cool at first.

Agreed

"¢ The
oceans are cooling

Now the authors of the 2006 study have submitted a
correction (pdf format). It turns out that a fault in the software on some
of the floats led to some temperature measurements being associated with the
wrong depth.

Meanwhile, work by other teams suggests that the
past warmth of the oceans has been overestimated. The problem was due to
expendable sensors that are thrown overboard and take measurements as they
sink.

I never had heard the claim that the oceans were cooling, so it does not
surprise me that they are not.  However, it is again interesting the
amount of due diligence that AGW supporter put in to the correction of any
temperature measurement the might refute global warming, while blithely
accepting the atrocious condition and biases in ground-based temperature
measurement because, well, because these instruments are telling the story they
want to hear.

"¢ The
cooling after 1940 shows CO₂ does not cause warming

The mid-century cooling appears to have been
largely due to a high concentration of sulphate aerosols in the atmosphere,
emitted by industrial activities and volcanic
eruptions. Sulphate aerosols have a cooling effect on the climate because
they scatter light from the Sun, reflecting its
energy back out into space.

The rise in sulphate aerosols was largely due to
the increase in industrial activities at the end of the second world war. In
addition, the large eruption of Mount Agung in 1963 produced aerosols which cooled the
lower atmosphere by about 0.5°C, while solar activity levelled off after
increasing at the beginning of the century

I think I was pretty fair in discussing the aerosol cooling hypothesis in
this paper, though many would disagree with the above statement's certainty.

Climate models that take into account only
natural factors, such as solar activity and volcanic eruptions, do not
reproduce 20th century temperatures very well. If, however, the models include
human emissions, including greenhouse gases and aerosols, they accurately reproduce
the 1940 to 1970 dip in temperatures.

I hope readers who have made it this far can supply the refutation of this
point:  Wrong, wrong, wrong.  Climate models initially matched
history poorly.  Today they match well because they have been tweaked and
adjusted and forced to match.  They match because they are programmed to
match.  And, as we discussed, they match only because they make
ridiculously low assumptions for natural forcings, and assume all natural
forcings causing temperatures to rise in the first half of the century
magically reversed in 1950, though there is no good evidence for it. 

"¢ It
was warmer during the Medieval period, with vineyards in England

In the southern hemisphere, the picture is even
more mixed, with evidence of both warm and cool periods around this time. The
Medieval Warm Period may have been partly a regional phenomenon, with the
extremes reflecting a redistribution of heat around the planet rather than a
big overall rise in the average global temperature.

What is clear, both from the temperature
reconstructions and from independent evidence "“ such as the extent of the
recent melting of mountain glaciers "“ is that the planet has been warmer in the
past few decades than at any time during the medieval period. In fact, the
world may not have been so warm for 6000 or even 125,000 years (see Climate myths: It has been warmer in the past,
what's the big deal?).

What really matters, though, is not how warm it
is now, but how warm it is going to get in the future. Even the temperature
reconstructions that show the greatest variations in the past 1000 years suggest
up until the 1980s, average temperature changes remained within a narrow band
spanning 1ºC at most. Now we are climbing out of that band, and the latest IPCC report (pdf format) predicts a further rise of
0.5ºC by 2030 and a whopping 6.4ºC by 2100 in the worst case scenario.

We have covered this pretty well in this paper, so again I won't go back
into it, except to highlight a couple of things we can learn from this
statement.  First, note the hubris again "“ it is warmer today than in the
last 125,000 years.  I sure wish there was a way to bet on this "“ I would
have only a one in 125,000 chance of being wrong in betting against this
statement.  Second, note the use of the worst case scenarios.  For
2100, we don't get the best case or even the average case, we get the worst
case.  Can you name another branch of science where people do this?
Can you imagine, say, a group out to measure the speed of light.  They are
going to get some middle figure with an error band of some range.
Wouldn't you expect them to day that they found the speed of light to be
so-and-so, plus or minus an error of such-and-such size?  If they were
climate scientists, they would instead announce that they have found the speed
of light could be as large as Z, that being the highest possible figure in
their error band.

"¢ We
are simply recovering from the Little Ice Age

Yet while there is some evidence of cold
intervals in parts of the southern hemisphere during this time, they do not appear to
coincide with those in the northern hemisphere. Such findings suggest the Little
Ice Age may have been more of a regional phenomenon than a global one.

Solar radiation was probably lower at times
during this period, especially during a dip in solar activity called the
Maunder minimum around 1700, but models and temperature reconstructions suggest
this would have reduced average global temperatures by 0.4ºC at most.

The larger falls in temperature in Europe and
North American may have been due to changes in atmospheric circulation over the
North Atlantic, or in the Gulf Stream, or both, reducing heat transport from
the tropics (see Climate
change sceptics lose vital argument).

The warming after the so-called Little Ice Age
may reflect both an increase in solar activity and a redistribution of heat
around the planet. In particular, the increase in global temperature in the
first half of the 20^th century may have been largely due to an increase
in solar activity. The continued warming in recent decades, however, cannot be
explained by increases in solar radiation alone

Remember the graphs we showed earlier "“ the arctic proxies look like the
current warming is a straight linear increase from the 1700s to today.  In
fact, in the IPCC spaghetti graph showing all those historic reconstructions,
they all show a natural warming from the 18^th and 19^th
century through the 20^th.  Again, AGW supporters really need to
explain why they are so confident that this natural warming trend stopped in
1945 or so, exactly and coincidently at the exact same moment that man-made
forcings caused the world to continue to warm, coincidently at about the same
rate it was warming naturally earlier in the century.

"¢ Warming
will cause an ice age in Europe

Few scientists think there will
be a rapid shutdown of circulation. Most ocean models predict no more than a
slowdown, probably towards the end of the century. This could slow or even
reverse some of the warming due to human emissions of greenhouse gases, which
might even be welcome in an overheated Europe, but the continent is not likely
to get colder than it is at present.

A slowdown in circulation would
affect many parts of the world by disrupting global rainfall patterns. But
these effects will be insignificant compared with the much greater changes
global warming will cause

I already mentioned that this had been refuted pretty well

"¢ Ice
cores show CO₂ increases lag behind temperature rises, disproving
the link to global warming

It takes about 5000 years for an
ice age to end and, after the initial 800 year lag, temperature and CO₂
concentrations in the atmosphere rise together for a further 4200 years.

What seems to have happened at
the end of the recent ice ages is that some factor "“ most probably orbital
changes "“ caused a rise in temperature. This led to an increase in CO₂,
resulting in further warming that caused more CO₂ to be released and
so on: a positive feedback that amplified a small change in temperature. At
some point, the shrinking of the ice sheets further amplified the warming.

Models suggest that rising
greenhouse gases, including CO₂, explains about 40% of the warming
as the ice ages ended. The figure is uncertain because it depends on how the
extent of ice coverage changed over time, and there is no way to pin this down
precisely.

I was extremely happy to see that they at least tried to
address the issue I raised, ie is it really realistic to have a process
dominated by positive feedback, and if so, why doesn't it run away.  Their
answer:

Finally, if higher temperatures lead
to more CO₂ and more CO₂ leads to higher temperatures,
why doesn't this positive feedback lead to a runaway greenhouse effect? There
are various limiting factors that kick in, the most important being that
infrared radiation emitted by Earth increases exponentially with temperature,
so as long as some infrared can escape from the atmosphere, at some point heat
loss catches up with heat retention.

Which might make sense EXCEPT that they are claiming that
today's temperature and level of CO2 are higher than these historical levels,
so we are already higher than the level where they claim "heat loss catches up
with heat retention."  So either their answer is right, and there is a
strong compensating process which is not built into their models, or they are
wrong and they still need to explain what keeps a positive feedback dominated
process from running away.

"¢ Ice
cores show CO₂ rising as temperatures fell

There are some mismatches though. Besides lags
at the end of ice ages, cores taken from the ice overlying the famous
lake below Vostok in Antarctica seemed to show that about 120,000 years
ago, the temperature plummeted sharply while CO₂ levels remained high
for many thousands of years.

The question is whether this is real or just a
reflection of the problems with working out the age of the trapped air and with
deuterium as a temperature indicator. Many researchers are working on ways to
independently date the air and the ice, and to improve temperature
reconstructions based on relative deuterium content. One involves working out
what is called the deuterium excess by comparing the relative amounts of
deuterium and oxygen-18 in the ice.

The deuterium excess reflects the temperature at
the sea surface where the water that later fell as snow evaporated, rather than
the surface temperature where the snow fell. It helps to reveal whether
variations in the relative deuterium content of the ice are a result of water
coming from a different source region rather than changes in local temperature.

In 2001, researchers used the deuterium excess to correct for some of the
problems with the temperature record of the Vostok ice core. Their results produce
a much closer fit between temperature and CO₂ levels and reduces the
mismatch around 120,000 years ago to a few thousand years.

I did not really raise this issue, as even the most enthusiastic AGW
supporter does not tend to claim that CO2 drives all historic temperature
changes.  However, again, note the pattern "“ any historic data that does
not fit with AGW data typically is scrutinized and "corrected." 
Articles discussing flaws in methodology in gathering such data are quickly published.
Contrast this with the difficulty scientists have in questioning any data that
supports AGW theory.  As we saw earlier, the New Scientist still can't
bring itself to utter the words "the Mann hockey stick was flawed."
Neither could the IPCC, they just sort of dropped it, or buried it in the midst
of 12 others, without even saying why the analysis that was the centerpiece of
their last report was strangely missing.

"¢ Mars
and Pluto are warming too

The Sun's energy output has not increased since
direct measurements began in 1978. If increased solar output really was
responsible, we should be seeing warming on all the planets and their moons,
not just Mars and Pluto.

Our solar system has eight planets, three dwarf
planets and quite a few moons with at least a rudimentary atmosphere, and thus
a climate of sorts. Their climates will be affected by local factors such as
orbital variations, changes in reflectance (albedo) and even volcanic
eruptions, so it would not be surprising if several planets and moons turn out
to be warming at any one time.

I agree we have a lot to learn about this, and nothing at all is
settled.  However, we now have evidence from at least 5 other terrestrial bodies
that are warming at the same time the Earth is warming.  Why do AGW
supporters resist at least investigating further?

"¢ Many
leading scientists question climate change

Climate change sceptics sometimes claim that
many leading scientists question climate change. Well, it all depends on what
you mean by "many" and "leading". For instance, in April
2006, 60 "leading scientists" signed a letter urging Canada's
new prime minister to review his country's commitment to the Kyoto protocol.

This appears to be the biggest recent list of
sceptics. Yet many, if not most, of the 60 signatories are not actively engaged
in studying climate change: some are not scientists at all and at least 15 are
retired.

Compare that with the dozens of statements on
climate change from various scientific organisations around the world
representing tens of thousands of scientists, the consensus position
represented by the IPCC reports and the 11,000 signatories to a petition condemning the Bush administration's
stance on climate science.

I have carefully avoided the game of dueling scientific numbers.  As to
the claim that the skeptic list "are not actively engaged in studying
climate change: some are not scientists at all and at least 15 are retired" I
would be thrilled if AGW supporters held to this standard in making their own
numbers.  But, they manage to abandon this standard by the next paragraph,
when they claim the pro-AGW numbers, like the 11,000, are open to the same
criticism (since there are only 500-600 true climate scientists in the world,
vs. physicist, meteorologists, etc). 

"¢ It's
all a conspiracy

Now that there is a consensus, those whose
findings challenge the orthodoxy are always going have a tougher time
convincing their peers, as in any field of science. For this reason, there will
inevitably be pressure on scientists who challenge the consensus. But findings
or ideas that clash with the idea of human-induced global warming have not been
suppressed or ignored "“ far from it.

Journalists do have an interest in promoting
themselves (and their books), while their employers want to boost their
audience and sell advertising. Publicity helps with all these aims, but you get
far more publicity by challenging the mainstream view than by promoting it.
Which helps explain why so many sections of the media continue to publish or
broadcast the claims of deniers, regardless of their merit.

The notion of a "conspiracy" of course, is a useful straw man, implying
devious villains in the SPECTRE conference room planning the overthrow of the
world.   I won't argue the point again, except to encourage you to
watch the news with a critical eye, and decide for yourself.  However, just
to get you started, ask yourself if these events are signs of healthy, unbiased
science:

· A
group of AGW supporters are trying to get the British government to use force
to block the publication of a skeptical movie (the Global Warming Swindle)

· AGW
supporters in California have included skeptical scientists such as MIT's Dr.
Richard Lindzen as defendants in a law suit, asking that damages be paid by
people and companies whose public speech doesn't conform to AGW theory

· Many
AGW skeptics have been unable to get scientists who have published publicly
funded research to reveal their data and methodology for critique.
Freedom of Information Act (FOIA) requests have become a necessary tool of
climate skeptics.

· When
a group began photographing temperature measurement points to document the
shortcomings in historical surface temperature measurements, the NOAA pulled
the locations of its measurement stations off the Internet so that these US
citizens could no longer take pictures of and critique US government
installations.

· Scientists
who question AGW theory are equated by AGW supporters with Holocaust deniers.

"¢ Hurricane
Katrina was caused by global warming

More data is needed settle the issue. Some are
looking to natural records of past
hurricane activity in stalagmites, lake deposits and coral rubble. Others
are re-analysing existing databases. In February 2007, one such re-analysis
concluded that over the past two decades, hurricane intensity has increased
in the Atlantic but not in other parts of the world (pdf format).

Yet another complicating factor is that changes
in climate can also change the paths that tropical cyclones tend to take,
determining whether they remain over oceans or strike land.

What every one agrees on is that over the past
few decades there has been a huge rise in the number of people being killed or
injured by hurricanes, and in damage to infrastructure, and this trend looks
set to continue. The main reason for this, however, is that more and more
people are living and building in hurricane zones.

Most of these three paragraphs is entirely correct "“ there is no evidence
that hurricane numbers or intensity are effected by global warming, and if they
are, whether they are increased or decreased.  However, Hurricane Katrina
was most certainly NOT caused by global warming.  Why can't they just say
that?   It may have been made stronger or weaker.  Its course
may have been altered.   But it was not created by warming.  By
the way, the year after Katrina saw a much smaller than average Atlantic
hurricane season.

"¢ Higher
CO₂ levels will boost plant growth and food production

But it is extremely difficult to generalise
about the overall impact on plant growth. Numerous groups around the world have
been conducting experiments in which plots of land
are supplied with enhanced CO₂, while comparable nearby plots remain
at normal levels.

While these experiments typically have found
initial elevations in the rate of plant growth, these have tended to level off
within a few years. In most cases this has been found to be the result of some
other limiting factor, such as the availability of nitrogen or water.

So the answer is yes, but there is a diminishing return at some point.
Isn't that the same as can be said for the CO2 greenhouse effect?

Predicting the world's overall changes in food
production in response to elevated CO₂ is virtually impossible.
Global production is expected to rise until the increase in local average
temperatures exceeds 3°C, but then start to fall. In tropical and dry regions
increases of just 1 to 2°C are expected to lead to falls in production. In
marginal lands where water is the greatest constraint, which includes much of
the developing world but also regions such as the western US, the losses may
greatly exceed the gains.

Have you noticed yet that things that might hurt the AGW-interventionist's
case always seem "impossible to predict" while the climate is well within our
prediction capabilities?

As for food crops, the factors are more complex.
The crops most widely used in the world for food in many cases depend on
particular combinations of soil type, climate, moisture, weather patterns and
the infrastructure of equipment, experience and distribution systems. If the
climate warms so much that crops no longer thrive in their traditional settings,
farming of some crops may be able to shift to adjacent areas, but others may
not. Rich farmers and countries will be able to adapt more easily than poorer
ones.

I love the rich-poor language.  The leftish New Scientist simply can't
help itself.  But I will accept this statement, and go further:  This
is the reason that aggressive actions to reduce CO2 that reduce economic
growth, particularly in the developing world, may not make sense.  To the
extent that some climate change will occur no matter what, or is already
programmed by our past actions, then a richer world can deal with it better
than a poorer one.

"¢ Polar
bear numbers are increasing

Yet recently there have been
claims that polar bear populations are increasing. So what's going on? There
are thought to be between 20,000 and 25,000 polar bears in 19 population groups
around the Arctic. While polar bear numbers are increasing in two of these
populations, two others are definitely in decline. We don't really know how the
rest of the populations are faring, so the truth is that no one can say for
sure how overall numbers are changing.

Again, I love this.  We can know the global temperature
increase over a century to a tenth of a degree but it is impossible to count
polar bears.

A comprehensive review (pdf) by the US Fish and Wildlife Service
concluded that shrinking sea ice is the primary cause for the decline seen in
these populations, and it recently proposed listing
polar bears as threatened (pdf) under the Endangered Species Act. The
International Conservation Union projects the bears' numbers will drop by 30% by 2050
(pdf) due to continued loss of Arctic sea ice.

Note that down 30% (which coming from an environmental
advocacy ground has got to be considered the most extreme possible estimate) is
not "extinct."  The article fails to address at all the issue that polar
bears have survived through eras when Arctic sea ice melted completely in the
summers.  And there are many reasons for threats to polar bear numbers "“
most experts would say that hunting and threats to habitat are much more
important factors than global temperatures.

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

The open comment thread for this paper can be found here. 

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

As stated in the introduction, the purpose of this paper has
not been to provide a balanced portrayal of Anthropogenic Global Warming (AGW) theory; its purpose instead is to
provide a comprehensive overview of skeptic's concerns with AGW theory.
However, the issues raised here are not necessarily new, and AGW supporters
have attempted to address many of them. 

The New
Scientist, a fairly strong and reliable voice for advocacy of anthropogenic
global warming theory, recently published its response to what it calls 26
myths about global warming, many of these "myths" being correlated loosely with
skeptics concerns about AGW theory as outlined in this paper.  Walking
through their points seems a reasonable way to entertain a rebuttal to the
skeptic's position.  Each of these has a link to the New Scientist article
in question.  I have tried to summarize the position with a quote, shown
in italics.  My response to each then follows.

Before I get into these 20 myths, note that many of the key
skeptic's questions are neatly avoided.   While the magazine gives
itself certain softball questions, it does not attempt to take on skeptics
questions such as:

• Isn't warming from CO2 a diminishing return, such that each 10ppm of CO2
  has less warming effect than the last 10 ppm?
• Isn't warming from CO2 asymptotic, such that total warming from CO2 is
  capped?
• Isn't 2/3 or more of the future warming in IPCC forecasts due to
  positive feedback effects that tend to be rare in stable systems and that even
  the IPCC admits are poorly understood?
• Aren't there a lot of problems with ground-based temperature measurements?
• Aren't the historical proxies for temperature diverging from
  measurements, such that the IPCC actually dropped many of the recent proxy
  measurements to hide this result?

There are many others, but we can get at them tangentially
through dealing with the 20 "myths" below

"¢ Human
CO₂ emissions are too tiny to matter

So what's going on? It is true that human
emissions of CO₂ are small compared with natural sources. But the
fact that CO₂ levels have remained steady until very recently shows
that natural emissions are usually balanced by natural absorptions. Now
slightly more CO₂ must be entering the atmosphere than is being
soaked up by carbon "sinks".

Though I do know that some skeptics will claim that man can't be changing
world CO2 levels, I don't believe I even tried to make that claim in this paper.

The more salient point in
asking whether human CO2 emissions are too tiny to matter is to ask whether the
change in composition of the atmosphere of 0.009% by human activities is
substantial enough to affect world climate in any important way, particularly
when the portion being increased, CO2, is a relatively weak greenhouse gas vs.
other portions.

"¢ We
can't do anything about climate change

It is true that the action taken
so far, such as the Kyoto Protocol, will only have a marginal effect. The
protocol's authors have always described it as a first step. But even before it
came into effect in 2005, the protocol has triggered some profound thinking
among governments, corporations and citizens about their carbon footprint and
how to reduce it. Industrialized countries such as the UK are planning for
emissions reductions of 60% or more by mid-century.

This is a bit of a straw man.  Certainly to the extent
that man is causing climate change, men with enough will can do something about
it.  The question is whether the costs justify the avoided change "“ this
is a question that I have addressed sufficiently and won't revisit here.
However, I would like to comment on this:

We may find that once the
process has begun, the world loses its addiction to carbon fuels surprisingly quickly.
Natural scientists fear "tipping points" in the climate system. But there are
also tipping points in social, economic and political systems. Once under way,
things can happen fast"¦

This is a statement to which I both agree and disagree.  I am a technological
optimist, and so generally accept that world-changing technologies will
continue to spring from man's mind, and that the introduction of these changes
can be fast and their impact dramatic.  The only reason that I am a tad
skeptical about this statement is that the vast majority of strong AGW
adherents are technology pessimists, so it would be uncharacteristic for them
to take such a position.  Absent unimagined new technologies, change of
the type AGW supporters are hoping for is actually not a positive
feedback process as implied in this statement. Why is it that climate
scientists see so many positive feedback processes, when these are actually so
rare? In fact, most investment decisions, for example investments to reduce CO2
emissions, follow a diminishing return relationship.  Early investors
capture the low-hanging fruit, while each successive wave of investment offers
a lower return (here, in CO2 reduction) for each incremental dollar invested.

"¢ The
'hockey stick' graph has been proven wrong

Most researchers would agree that while the
original hockey stick can "“ and has "“ been improved in a number of ways, it was
not far off the mark. Most later temperature reconstructions fall within the
error bars of the original hockey stick. Some show far more variability leading
up to the 20^th century than the hockey stick, but none suggest that
it has been warmer at any time in the past 1000 years than in the last part of
the 20^th century.

No one statement by AGW supporters would do more to build my confidence in
their findings than to actually have someone say "the Mann hockey stick was a
deeply flawed analysis, and we have taken great pains to make sure the flaws identified
in Mann are not present in other historical reconstructions."  However,
when I see the statement above, I am left to wonder if any of the flaws in Mann
have actually been corrected in other works, or if systematic errors still
exist.  Since AGW supporters refuse to acknowledge flaws in Mann, it is
almost certain that these flaws still exist in the other analyses (therefore
making it unsurprising that new analyses show roughly the same results).
Remember that Mann was replaced by Biffra as lead author of this section of the
Fourth IPCC report, and it was Biffra who dropped 20-30 years of recent data
from his historical reconstruction when it did not show the result that he
wanted it to.

"¢ Chaotic
systems are not predictable

Getting reasonably accurate
predictions is a matter of choosing the right timescale: days in the case of
weather, decades in the case of climate.

Climate scientists sometimes
refer to the effects of chaos as intrinsic or unforced variability: the
unpredictable changes that arise from the dynamic interactions between the
oceans and atmosphere rather than being a result of "forcings" such
as changes in solar irradiance or greenhouse gases.

The crucial point is that
unforced variability occurs within a relatively narrow range. It is constrained
by the major factors influencing climate: it might make some winters bit a
warmer, for instance, but it cannot make winters warmer than summers

There are systems people who would both agree and disagree
with this statement.  The real study of chaotic systems is barely older
than the study of global warming, and most mathematicians would say that the
issue of long-term predictability of macro trends in chaotic systems is not
settled science.

However, one issue the statement overlooks is that even if
chaotic systems have some long-term order, at least when "viewed from a
distance," this does not mean that the drivers of those long-term trends can be
discerned by those of us standing in the chaos.  So while it may be
theoretically possible to predict long-scale climate changes, it may still be
impossible to discern the true drivers of these climate systems amidst the
chaos, making the long-term prediction problem moot.

Remember, no one has a thermometer that provides two readings "“ temperature
due to "natural" causes and temperature due to man-made forcings. 
The only argument one can make outside of a laboratory is to try to correlate
temperature changes to certain other variables, like CO2 level.  But in a
chaotic system, when thousands of variables may matter, and there are all kinds
of cross-dependencies between variables, definitively showing direct
correlation, much less causation, is very hard, possibly impossible. 
Remember, outside lab experiments, climate scientists main argument that CO2 is
causing current warming is "We have checked everything else it possibly could
be, and it wasn't those things, so it must be CO2."  In a chaotic system,
such a statement borders on hubris.

"¢ We
can't trust computer models of climate

Climate is average weather, and it can vary unpredictably
only within the limits set by major influences like the Sun and levels of
greenhouse gases in the atmosphere. We might not be able to say whether it will
rain at noon in a week's time, but we can be confident that the summers will be
hotter than winters for as long as the Earth's axis remains tilted.

The validity of models can be tested against
climate history. If they can predict the past (which the best models are pretty
good at) they are probably on the right track for predicting the future "“ and
indeed have successfully done so.

I hope that if you have learned anything from this paper, you already know
how to refute the statement above.  Climate models match history because
they have been tuned and tweaked and overridden to do so.  The fact that
they then can reproduce history is meaningless.  Even more, you should run
away quickly from anyone who makes this statement, because they are either
ignorant of what they are talking about or they are trying to sell you the
Brooklyn Bridge.

Finally, the claim is sometimes
made that if computer models were any good, people would be using them to
predict the stock market. Well, they are!

A lot of trading in the
financial markets is already carried out by computers. Many base their
decisions on fairly simple algorithms designed to exploit tiny profit margins,
but others rely on more sophisticated long-term models.

Sorry, but this is a facile and ignorant mis-interpretation of what
financial models are doing.  Yes, people are running long-term financial
models as part of a trading strategy, but these models feed into very
short-term trading decisions.  If you looked at the output from these long-term
models, you would see that they are changing constantly as new data flows
in.  There is an old joke about two campers who see a bear growling at
them.  One of them starts putting his tennis shoes on.  The other one
says to him "Why are you putting your shoes on?  You can't outrun that
bear."   His friend replied "I don't have to outrun the bear.  I
just have to outrun you."  Traders' long-term models work the same.
They don't actually expect them to be right, they just want them to be better,
based on current conditions, than other traders' models, then they can make
money.

"¢ They
predicted global cooling in the 1970s

Indeed they did"¦. However, Schneider soon
realised he had overestimated the cooling effect of aerosol pollution and
underestimated the effect of CO₂, meaning warming was more likely
than cooling in the long run"¦.

The calls for action to prevent further
human-induced global warming, by contrast, are based on an enormous body of
research by thousands of scientists over more than a century that has been
subjected to intense "“ and sometimes ferocious "“ scrutiny. According to the
latest IPCC report, it is more than
90% certain that the world is already warming as a result of human activity

We have already dealt with aerosols, and unlike many skeptics I have not
really held the 1970's global cooling panic against the climate
community.  The last paragraph is just circular.  Saying the IPCC is
90% sure does not answer the arguments about what skeptics feel the IPCC is
ignoring.

"¢ It's
been far warmer in the past, what's the big deal?

First of all, it is worth bearing in mind that
any data on global temperatures before about 150 years ago is an estimate, a
reconstruction based on second-hand evidence such as ice cores and isotopic
ratios. The evidence becomes sparser the further back we look, and its
interpretation often involves a set of assumptions. In other words, a fair
amount of guesswork.

This is hilarious.  What happened to their confidence in Mann and
1000-year temperature reconstructions just a few myths back?  But to
continue, the answer is basically yes, but:

The important question is what
is causing the current, rapid warming? We cannot dismiss it as natural
variation just because the planet has been warmer at various times in the past.
Many studies suggest it can only be explained by taking into account human
activity.

Nor does the fact that it has
been warmer in the past mean that future warming is nothing to worry about. The
sea level has been tens of metres higher during past warm periods, enough to
submerge most major cities around the world.

Here is why it matters "“ beyond the laboratory evidence of the greenhouse
effect, which tells us merely that there is an affect and not how strong it is,
the main evidence cited by AGW supporters for current warming being man-made is
to try to show that current warming is somehow unprecedented, and therefore
unlikely to be natural.  So it is odd here that AGW supporters simply
shrug their shoulders here and say that it is not important that current
warming be unprecedented.

"¢ It's
too cold where I live - warming will be great

This does not sound too bad, and for many people
it won't be. Wealthy individuals and countries will be able to adapt to most
short-term changes, whether it means buying an air conditioner or switching to
crops better suited to the changing climate. Rainfall will fall in
mid-latitudes but rise in high latitudes, and initially agricultural yields
will probably.  Some regions will suffer, though. Africa could be hardest
hit, with yields predicted to halve in some countries as early as 2020.

As global temperature climbs to 3°C above
present levels - which is likely
to happen before the end of this century if greenhouse emissions continue
unabated - the consequences will become increasingly severe. More than a third
of species face extinction. Agricultural yields will start to fall in many
parts of the world. Millions of people will be at risk from coastal flooding.
Heatwaves, droughts, floods and wildfires will take an ever greater toll.

I hope readers will accept that I am not exaggerating or constructing straw
men when I talk about the dire predictions by AGW supporters.  There is
nothing here that we have not dealt with earlier, except perhaps the
rainfall.  Of late, AGW supporters seem to have shifted to rainfall
(rather than sea level rise) as their lead scary topic.  Note, however,
that even the IPCC admits that it and all of its modelers really do not
understand (even a little bit) the effect of global warming on rainfall and
drought.  Logic says that with more water evaporated, while global warming
may cause now local draughts, overall rainfall should increase.  I would
bet any amount of money that lower economic growth due to aggressive CO2 abatement
will have a far more deleterious effect on worldwide agricultural yields than
global warming.

"¢ Global
warming is down to the Sun, not humans

So what role, if any, have solar fluctuations
had in recent temperature changes? While we can work out how Earth's orbit has
changed going back many millions of years, we have no first-hand record of the
changes in solar output associated with sunspots before the 20^th century.

It is true that sunspot records go back to the
17^th century, but sunspots actually block the Sun's radiation. It is
the smaller bright spots (faculae) that increase the Sun's output and these
were not recorded until more recently. The correlation between sunspots and
bright faculae is not perfect, so estimates of solar activity based on sunspot
records may be out by as much as 30%.

The other method of working out past solar
activity is to measure levels of carbon-14 and beryllium-10 in tree rings and
ice cores. These isotopes are formed when cosmic rays hit the atmosphere, and
higher sunspot activity is associated with increases in the solar wind that
deflect more galactic cosmic rays away from Earth. Yet again, though, the
correlation is not perfect. What is more, recent evidence suggests that the
deposition of beryllium-10 can
be affected by climate changes, making it even less reliable as a measure
of past solar activity.

This is again a pretty hilarious statement.  One could easily argue
that temperature and CO2 proxies have at least as much
uncertainty.  One wonders why AGW advocates do not seem as concerned about
the errors in the proxies they hold dear.  But anyway, to continue:

But even if solar forcing in the past was more
important than this estimate suggests, as some scientists think, there is no
correlation between solar activity and the strong warming during the past 40
years. Claims that this is the case have not stood up to scrutiny (pdf document).

Direct measurements of solar output since 1978
show a steady rise and fall over the 11-year sunspot cycle, but no upwards or downward trend .

Similarly, there is no trend in direct
measurements of the Sun's ultraviolet output and in cosmic rays. So for the
period for which we have direct, reliable records, the Earth has warmed
dramatically even though there has been no corresponding rise in any kind of
solar activity.

This is another you-study-my-study pissing match.  I am happy to admit
that our knowledge of the sun's changing impact on climate is poor, and that it
is hard to separate out this one effect in a chaotic system.  I refuse to
fall into the same scientific hubris as AGW supporters.  However, those
who think the sun has some contribution to warming are buttressed by the
knowledge that they are working with the main driver of climate, rather than a
secondary variable.

"¢ It's
all down to cosmic rays

There is no convincing evidence
that cosmic rays are a major factor determining cloud cover. The ionising of
air by cosmic rays will impart an electric charge to aerosols, which in theory
could encourage them to clump together to form particles large enough for cloud
droplets to form around, called "cloud condensation nuclei".

But cloud physicists say it has
yet to be shown that such clumping occurs. And even if it does, it seems
far-fetched to expect any great effect on the amount of clouds in the atmosphere.
Most of the atmosphere, even relatively clean marine air, has plenty of cloud
condensation nuclei already.

A series of attempts by
Svensmark to show an effect have come unstuck. Initially, Svensmark claimed
there was a correlation between cosmic ray intensity and satellite measurements
of total cloud cover since the 1980s "“ yet a correlation does not prove cause
and effect. It could equally well reflect changes in solar irradiance, which
inversely correlate with cosmic ray intensity.

I am starting to notice a trend here of making statements about competing
that could be applied equally well to AGW theory.  And what about all
those points they made above, reminding us over and over that CO2 greenhouse
theory works in the lab.  Now the lab is not good enough?

However, I would accept that the cosmic ray theory is pretty undeveloped and
not acceptably proven.  It has had a number of fits and starts.  Just
like CO2 greenhouse theory, the cosmic ray effect on climate can be reproduced
in the lab, but it is really hard to parse out its effects in the chaotic
climate.

"¢ CO₂
isn't the most important greenhouse gas

At some of these overlaps, the
atmosphere already absorbs 100% of radiation, meaning that adding more
greenhouse gases cannot increase absorption at these specific frequencies. For
other frequencies, only a small proportion is currently absorbed, so higher
levels of greenhouse gases do make a difference.

This means that when it comes to
the greenhouse effect, two plus two does not equal four.

Wow!  An AGW supporter actually said this in public.  This is to
our point that there is a diminishing return from incremental CO2 in the
atmosphere.  Of course, they say this in the context of trying to show why
water isn't as important as it might seem, but still, it's there

But the overall quantities of these other gases
are tiny. Even allowing for the relative strength of the effects, CO₂
is still responsible for two-thirds
of the additional warming caused by all the greenhouse gases emitted as a
result of human activity.

Water vapour will play a huge role in the
centuries to come, though. Climate models, backed by satellite
measurements, suggest that the amount of water vapour in the upper
troposphere (about 5 to 10 kilometres up) will double by the end of this
century as temperatures rise.

This will result in roughly twice as much
warming than if water vapour remained constant. Changes in clouds could lead to
even greater amplification of the warming or reduce it "“ there is great uncertainty
about this. What is certain is that, in the jargon of climate science, water
vapour is a feedback, but not a forcing.

Again, I am not getting into this, we covered it plenty in the paper.
When they say "CO2 is still responsible for two-thirds of the additional
warming" (and remember this is an output of their models, not any other
analysis)  what they really mean is that "our models that were programmed
to have CO2 drive the climate show that CO2 drives the climate."
Note that in a three paragraph answer about the effect of water vapor as
a climate feedback, only three words "“ "or reduce it" "“ acknowledge that it
might actually have a negative feedback effect, despite the fact that even the
IPCC includes cloud cover as a negative feedback.  They just don't want to
admit a negative feedback might even exist.

"¢ The
lower atmosphere is cooling, not warming

One study in Science
revealed errors in the way satellite data had been collected and interpreted.
For instance, the orbit of satellites gradually slows, which has to be taken
into account because it affects the time of day at which temperature recording
are taken. This problem was always recognised, but the corrections were given
the wrong sign (negative instead positive and vice versa).

A second study, also
in Science, looked at the weather balloon data. Measurements of the air
temperature during the day can be skewed if the instruments are heated by
sunlight. Over the years the makers of weather balloons had come up with better
methods of preventing or correcting for this effect, but because no one had
taken these improvements into account, the more accurate measurements appeared
to show daytime temperatures getting cooler.

The corrected temperature records show that
tropospheric temperatures are indeed rising at roughly the same rate as surface
temperatures. Or, as a 2006 report by the US Climate Change Science Program (pdf) puts
it: "For recent decades, all current atmospheric data sets now show
global-average warming that is similar to the surface warming." This one
appears settled.

There is still some ambiguity in the tropics,
where most measurements show the surface warming faster than the upper
troposphere, whereas the models predict faster warming of the atmosphere.
However, this is a minor discrepancy compared with cooling of the entire
troposphere and could just be due to the errors of margin inherent in both the
observations and the models.

First, observe absolutely ruthless efforts to apply corrections and
adjustments to any measurement that does not fit their theory, while blithely
accepting the surface temperature measurements that we showed can be really
unreliable.  Given the choice of focusing on managing satellite
temperatures up or surface temperature down, you can see which they
chose.   Second, note that this is another narrow one study
conclusion.  AGW supporters frequently cite single studies (conducted by
AGW supporters) that overturn skeptics arguments as having "settled" the
issue.  There are still many reasons to think that troposphere temperature
increases are less than surface increases.  Finally, even temperature
increases that were the same between the surface and the troposphere would be a
real problem for AGW theory.  The authors here act like this
surface-troposphere issue is a minor deal, but in fact if AGW theory is right,
the troposphere has to warm more, because that is where the extra heat
is being absorbed.  This is not at all settled. 

"¢ Antarctica
is getting cooler, not warmer, disproving global warming

It is clear that the Antarctic Peninsula, which juts
out from the mainland of Antarctica towards South America, has warmed
significantly. The continent's interior was thought to have warmed too, but in
2002 a new analysis of
records from 1966 to 2000 concluded that it has cooled overall"¦.

Climate models do not predict an evenly spread
warming of the whole planet: changes in wind patterns and ocean currents can
change the distribution of heat, leading to some parts warming much faster than
average, while others cool at first.

Agreed

"¢ The
oceans are cooling

Now the authors of the 2006 study have submitted a
correction (pdf format). It turns out that a fault in the software on some
of the floats led to some temperature measurements being associated with the
wrong depth.

Meanwhile, work by other teams suggests that the
past warmth of the oceans has been overestimated. The problem was due to
expendable sensors that are thrown overboard and take measurements as they
sink.

I never had heard the claim that the oceans were cooling, so it does not
surprise me that they are not.  However, it is again interesting the
amount of due diligence that AGW supporter put in to the correction of any
temperature measurement the might refute global warming, while blithely
accepting the atrocious condition and biases in ground-based temperature
measurement because, well, because these instruments are telling the story they
want to hear.

"¢ The
cooling after 1940 shows CO₂ does not cause warming

The mid-century cooling appears to have been
largely due to a high concentration of sulphate aerosols in the atmosphere,
emitted by industrial activities and volcanic
eruptions. Sulphate aerosols have a cooling effect on the climate because
they scatter light from the Sun, reflecting its
energy back out into space.

The rise in sulphate aerosols was largely due to
the increase in industrial activities at the end of the second world war. In
addition, the large eruption of Mount Agung in 1963 produced aerosols which cooled the
lower atmosphere by about 0.5°C, while solar activity levelled off after
increasing at the beginning of the century

I think I was pretty fair in discussing the aerosol cooling hypothesis in
this paper, though many would disagree with the above statement's certainty.

Climate models that take into account only
natural factors, such as solar activity and volcanic eruptions, do not
reproduce 20th century temperatures very well. If, however, the models include
human emissions, including greenhouse gases and aerosols, they accurately reproduce
the 1940 to 1970 dip in temperatures.

I hope readers who have made it this far can supply the refutation of this
point:  Wrong, wrong, wrong.  Climate models initially matched
history poorly.  Today they match well because they have been tweaked and
adjusted and forced to match.  They match because they are programmed to
match.  And, as we discussed, they match only because they make
ridiculously low assumptions for natural forcings, and assume all natural
forcings causing temperatures to rise in the first half of the century
magically reversed in 1950, though there is no good evidence for it. 

"¢ It
was warmer during the Medieval period, with vineyards in England

In the southern hemisphere, the picture is even
more mixed, with evidence of both warm and cool periods around this time. The
Medieval Warm Period may have been partly a regional phenomenon, with the
extremes reflecting a redistribution of heat around the planet rather than a
big overall rise in the average global temperature.

What is clear, both from the temperature
reconstructions and from independent evidence "“ such as the extent of the
recent melting of mountain glaciers "“ is that the planet has been warmer in the
past few decades than at any time during the medieval period. In fact, the
world may not have been so warm for 6000 or even 125,000 years (see Climate myths: It has been warmer in the past,
what's the big deal?).

What really matters, though, is not how warm it
is now, but how warm it is going to get in the future. Even the temperature
reconstructions that show the greatest variations in the past 1000 years suggest
up until the 1980s, average temperature changes remained within a narrow band
spanning 1ºC at most. Now we are climbing out of that band, and the latest IPCC report (pdf format) predicts a further rise of
0.5ºC by 2030 and a whopping 6.4ºC by 2100 in the worst case scenario.

We have covered this pretty well in this paper, so again I won't go back
into it, except to highlight a couple of things we can learn from this
statement.  First, note the hubris again "“ it is warmer today than in the
last 125,000 years.  I sure wish there was a way to bet on this "“ I would
have only a one in 125,000 chance of being wrong in betting against this
statement.  Second, note the use of the worst case scenarios.  For
2100, we don't get the best case or even the average case, we get the worst
case.  Can you name another branch of science where people do this?
Can you imagine, say, a group out to measure the speed of light.  They are
going to get some middle figure with an error band of some range.
Wouldn't you expect them to day that they found the speed of light to be
so-and-so, plus or minus an error of such-and-such size?  If they were
climate scientists, they would instead announce that they have found the speed
of light could be as large as Z, that being the highest possible figure in
their error band.

"¢ We
are simply recovering from the Little Ice Age

Yet while there is some evidence of cold
intervals in parts of the southern hemisphere during this time, they do not appear to
coincide with those in the northern hemisphere. Such findings suggest the Little
Ice Age may have been more of a regional phenomenon than a global one.

Solar radiation was probably lower at times
during this period, especially during a dip in solar activity called the
Maunder minimum around 1700, but models and temperature reconstructions suggest
this would have reduced average global temperatures by 0.4ºC at most.

The larger falls in temperature in Europe and
North American may have been due to changes in atmospheric circulation over the
North Atlantic, or in the Gulf Stream, or both, reducing heat transport from
the tropics (see Climate
change sceptics lose vital argument).

The warming after the so-called Little Ice Age
may reflect both an increase in solar activity and a redistribution of heat
around the planet. In particular, the increase in global temperature in the
first half of the 20^th century may have been largely due to an increase
in solar activity. The continued warming in recent decades, however, cannot be
explained by increases in solar radiation alone

Remember the graphs we showed earlier "“ the arctic proxies look like the
current warming is a straight linear increase from the 1700s to today.  In
fact, in the IPCC spaghetti graph showing all those historic reconstructions,
they all show a natural warming from the 18^th and 19^th
century through the 20^th.  Again, AGW supporters really need to
explain why they are so confident that this natural warming trend stopped in
1945 or so, exactly and coincidently at the exact same moment that man-made
forcings caused the world to continue to warm, coincidently at about the same
rate it was warming naturally earlier in the century.

"¢ Warming
will cause an ice age in Europe

Few scientists think there will
be a rapid shutdown of circulation. Most ocean models predict no more than a
slowdown, probably towards the end of the century. This could slow or even
reverse some of the warming due to human emissions of greenhouse gases, which
might even be welcome in an overheated Europe, but the continent is not likely
to get colder than it is at present.

A slowdown in circulation would
affect many parts of the world by disrupting global rainfall patterns. But
these effects will be insignificant compared with the much greater changes
global warming will cause

I already mentioned that this had been refuted pretty well

"¢ Ice
cores show CO₂ increases lag behind temperature rises, disproving
the link to global warming

It takes about 5000 years for an
ice age to end and, after the initial 800 year lag, temperature and CO₂
concentrations in the atmosphere rise together for a further 4200 years.

What seems to have happened at
the end of the recent ice ages is that some factor "“ most probably orbital
changes "“ caused a rise in temperature. This led to an increase in CO₂,
resulting in further warming that caused more CO₂ to be released and
so on: a positive feedback that amplified a small change in temperature. At
some point, the shrinking of the ice sheets further amplified the warming.

Models suggest that rising
greenhouse gases, including CO₂, explains about 40% of the warming
as the ice ages ended. The figure is uncertain because it depends on how the
extent of ice coverage changed over time, and there is no way to pin this down
precisely.

I was extremely happy to see that they at least tried to
address the issue I raised, ie is it really realistic to have a process
dominated by positive feedback, and if so, why doesn't it run away.  Their
answer:

Finally, if higher temperatures lead
to more CO₂ and more CO₂ leads to higher temperatures,
why doesn't this positive feedback lead to a runaway greenhouse effect? There
are various limiting factors that kick in, the most important being that
infrared radiation emitted by Earth increases exponentially with temperature,
so as long as some infrared can escape from the atmosphere, at some point heat
loss catches up with heat retention.

Which might make sense EXCEPT that they are claiming that
today's temperature and level of CO2 are higher than these historical levels,
so we are already higher than the level where they claim "heat loss catches up
with heat retention."  So either their answer is right, and there is a
strong compensating process which is not built into their models, or they are
wrong and they still need to explain what keeps a positive feedback dominated
process from running away.

"¢ Ice
cores show CO₂ rising as temperatures fell

There are some mismatches though. Besides lags
at the end of ice ages, cores taken from the ice overlying the famous
lake below Vostok in Antarctica seemed to show that about 120,000 years
ago, the temperature plummeted sharply while CO₂ levels remained high
for many thousands of years.

The question is whether this is real or just a
reflection of the problems with working out the age of the trapped air and with
deuterium as a temperature indicator. Many researchers are working on ways to
independently date the air and the ice, and to improve temperature
reconstructions based on relative deuterium content. One involves working out
what is called the deuterium excess by comparing the relative amounts of
deuterium and oxygen-18 in the ice.

The deuterium excess reflects the temperature at
the sea surface where the water that later fell as snow evaporated, rather than
the surface temperature where the snow fell. It helps to reveal whether
variations in the relative deuterium content of the ice are a result of water
coming from a different source region rather than changes in local temperature.

In 2001, researchers used the deuterium excess to correct for some of the
problems with the temperature record of the Vostok ice core. Their results produce
a much closer fit between temperature and CO₂ levels and reduces the
mismatch around 120,000 years ago to a few thousand years.

I did not really raise this issue, as even the most enthusiastic AGW
supporter does not tend to claim that CO2 drives all historic temperature
changes.  However, again, note the pattern "“ any historic data that does
not fit with AGW data typically is scrutinized and "corrected." 
Articles discussing flaws in methodology in gathering such data are quickly published.
Contrast this with the difficulty scientists have in questioning any data that
supports AGW theory.  As we saw earlier, the New Scientist still can't
bring itself to utter the words "the Mann hockey stick was flawed."
Neither could the IPCC, they just sort of dropped it, or buried it in the midst
of 12 others, without even saying why the analysis that was the centerpiece of
their last report was strangely missing.

"¢ Mars
and Pluto are warming too

The Sun's energy output has not increased since
direct measurements began in 1978. If increased solar output really was
responsible, we should be seeing warming on all the planets and their moons,
not just Mars and Pluto.

Our solar system has eight planets, three dwarf
planets and quite a few moons with at least a rudimentary atmosphere, and thus
a climate of sorts. Their climates will be affected by local factors such as
orbital variations, changes in reflectance (albedo) and even volcanic
eruptions, so it would not be surprising if several planets and moons turn out
to be warming at any one time.

I agree we have a lot to learn about this, and nothing at all is
settled.  However, we now have evidence from at least 5 other terrestrial bodies
that are warming at the same time the Earth is warming.  Why do AGW
supporters resist at least investigating further?

"¢ Many
leading scientists question climate change

Climate change sceptics sometimes claim that
many leading scientists question climate change. Well, it all depends on what
you mean by "many" and "leading". For instance, in April
2006, 60 "leading scientists" signed a letter urging Canada's
new prime minister to review his country's commitment to the Kyoto protocol.

This appears to be the biggest recent list of
sceptics. Yet many, if not most, of the 60 signatories are not actively engaged
in studying climate change: some are not scientists at all and at least 15 are
retired.

Compare that with the dozens of statements on
climate change from various scientific organisations around the world
representing tens of thousands of scientists, the consensus position
represented by the IPCC reports and the 11,000 signatories to a petition condemning the Bush administration's
stance on climate science.

I have carefully avoided the game of dueling scientific numbers.  As to
the claim that the skeptic list "are not actively engaged in studying
climate change: some are not scientists at all and at least 15 are retired" I
would be thrilled if AGW supporters held to this standard in making their own
numbers.  But, they manage to abandon this standard by the next paragraph,
when they claim the pro-AGW numbers, like the 11,000, are open to the same
criticism (since there are only 500-600 true climate scientists in the world,
vs. physicist, meteorologists, etc). 

"¢ It's
all a conspiracy

Now that there is a consensus, those whose
findings challenge the orthodoxy are always going have a tougher time
convincing their peers, as in any field of science. For this reason, there will
inevitably be pressure on scientists who challenge the consensus. But findings
or ideas that clash with the idea of human-induced global warming have not been
suppressed or ignored "“ far from it.

Journalists do have an interest in promoting
themselves (and their books), while their employers want to boost their
audience and sell advertising. Publicity helps with all these aims, but you get
far more publicity by challenging the mainstream view than by promoting it.
Which helps explain why so many sections of the media continue to publish or
broadcast the claims of deniers, regardless of their merit.

The notion of a "conspiracy" of course, is a useful straw man, implying
devious villains in the SPECTRE conference room planning the overthrow of the
world.   I won't argue the point again, except to encourage you to
watch the news with a critical eye, and decide for yourself.  However, just
to get you started, ask yourself if these events are signs of healthy, unbiased
science:

· A
group of AGW supporters are trying to get the British government to use force
to block the publication of a skeptical movie (the Global Warming Swindle)

· AGW
supporters in California have included skeptical scientists such as MIT's Dr.
Richard Lindzen as defendants in a law suit, asking that damages be paid by
people and companies whose public speech doesn't conform to AGW theory

· Many
AGW skeptics have been unable to get scientists who have published publicly
funded research to reveal their data and methodology for critique.
Freedom of Information Act (FOIA) requests have become a necessary tool of
climate skeptics.

· When
a group began photographing temperature measurement points to document the
shortcomings in historical surface temperature measurements, the NOAA pulled
the locations of its measurement stations off the Internet so that these US
citizens could no longer take pictures of and critique US government
installations.

· Scientists
who question AGW theory are equated by AGW supporters with Holocaust deniers.

"¢ Hurricane
Katrina was caused by global warming

More data is needed settle the issue. Some are
looking to natural records of past
hurricane activity in stalagmites, lake deposits and coral rubble. Others
are re-analysing existing databases. In February 2007, one such re-analysis
concluded that over the past two decades, hurricane intensity has increased
in the Atlantic but not in other parts of the world (pdf format).

Yet another complicating factor is that changes
in climate can also change the paths that tropical cyclones tend to take,
determining whether they remain over oceans or strike land.

What every one agrees on is that over the past
few decades there has been a huge rise in the number of people being killed or
injured by hurricanes, and in damage to infrastructure, and this trend looks
set to continue. The main reason for this, however, is that more and more
people are living and building in hurricane zones.

Most of these three paragraphs is entirely correct "“ there is no evidence
that hurricane numbers or intensity are effected by global warming, and if they
are, whether they are increased or decreased.  However, Hurricane Katrina
was most certainly NOT caused by global warming.  Why can't they just say
that?   It may have been made stronger or weaker.  Its course
may have been altered.   But it was not created by warming.  By
the way, the year after Katrina saw a much smaller than average Atlantic
hurricane season.

"¢ Higher
CO₂ levels will boost plant growth and food production

But it is extremely difficult to generalise
about the overall impact on plant growth. Numerous groups around the world have
been conducting experiments in which plots of land
are supplied with enhanced CO₂, while comparable nearby plots remain
at normal levels.

While these experiments typically have found
initial elevations in the rate of plant growth, these have tended to level off
within a few years. In most cases this has been found to be the result of some
other limiting factor, such as the availability of nitrogen or water.

So the answer is yes, but there is a diminishing return at some point.
Isn't that the same as can be said for the CO2 greenhouse effect?

Predicting the world's overall changes in food
production in response to elevated CO₂ is virtually impossible.
Global production is expected to rise until the increase in local average
temperatures exceeds 3°C, but then start to fall. In tropical and dry regions
increases of just 1 to 2°C are expected to lead to falls in production. In
marginal lands where water is the greatest constraint, which includes much of
the developing world but also regions such as the western US, the losses may
greatly exceed the gains.

Have you noticed yet that things that might hurt the AGW-interventionist's
case always seem "impossible to predict" while the climate is well within our
prediction capabilities?

As for food crops, the factors are more complex.
The crops most widely used in the world for food in many cases depend on
particular combinations of soil type, climate, moisture, weather patterns and
the infrastructure of equipment, experience and distribution systems. If the
climate warms so much that crops no longer thrive in their traditional settings,
farming of some crops may be able to shift to adjacent areas, but others may
not. Rich farmers and countries will be able to adapt more easily than poorer
ones.

I love the rich-poor language.  The leftish New Scientist simply can't
help itself.  But I will accept this statement, and go further:  This
is the reason that aggressive actions to reduce CO2 that reduce economic
growth, particularly in the developing world, may not make sense.  To the
extent that some climate change will occur no matter what, or is already
programmed by our past actions, then a richer world can deal with it better
than a poorer one.

"¢ Polar
bear numbers are increasing

Yet recently there have been
claims that polar bear populations are increasing. So what's going on? There
are thought to be between 20,000 and 25,000 polar bears in 19 population groups
around the Arctic. While polar bear numbers are increasing in two of these
populations, two others are definitely in decline. We don't really know how the
rest of the populations are faring, so the truth is that no one can say for
sure how overall numbers are changing.

Again, I love this.  We can know the global temperature
increase over a century to a tenth of a degree but it is impossible to count
polar bears.

A comprehensive review (pdf) by the US Fish and Wildlife Service
concluded that shrinking sea ice is the primary cause for the decline seen in
these populations, and it recently proposed listing
polar bears as threatened (pdf) under the Endangered Species Act. The
International Conservation Union projects the bears' numbers will drop by 30% by 2050
(pdf) due to continued loss of Arctic sea ice.

Note that down 30% (which coming from an environmental
advocacy ground has got to be considered the most extreme possible estimate) is
not "extinct."  The article fails to address at all the issue that polar
bears have survived through eras when Arctic sea ice melted completely in the
summers.  And there are many reasons for threats to polar bear numbers "“
most experts would say that hunting and threats to habitat are much more
important factors than global temperatures.

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here.  Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

The open comment thread for this paper can be found here. 

A while back, I discussed an effort by Anthony Watts to create a pictorial data base of the US Historical Climate Network, the 1000 or so temperature and weather sensors whose data are used in historical climate numbers, including IPCC and NOAA and GISS global warming data bases. 

Already, this effort has identified numerous egregious installations that call into question the quality of historical temperature measurement.  Note here and here and here and here.  The whole data base is at SurfaceStations.org and my humble contributions are here and here.  Was 2006 the second warmest of all time, or did 2006 have the most hot exhaust blowing on measurement instruments?

Roger Pielke, a climate scientist in Colorado, reports on an odd response by the NOAA to this effort:

Recently, Anthony Watts has established a website [www.surfacestations.org] to record these photographs. He has worked to assure that the photographs are obtained appropriately.

As a result of this effort, NOAA has removed location information
from their website as to where they are located. This information has
been available there for years.

There are a few USHCN stations at people's homes, so in some cases there may be privacy concerns, but most all of the ones I have seen are at public locations, from fire houses to ranger stations to water plants.  Pielke offers up a logical solution for where there are privacy issues:

"over 4 years ago there was a big push in the Cooperative Observer
program to make sure that all 7000+ sites across the country were
photodocumented. All 120 Data Acquisition Programs were equipped with
high quality digital cameras. Most took photos. However, at the higher
levels where they were developing the upload and archive system for the
photos the issue of observer privacy was raised and as best we can tell
the result was that those photos were not archived and certainly are
not available."

This is a very disturbing development, as individuals in NOAA's
leadership have used their authority to prevent the scientific
community and the public access to critical information that is being
used as part of establishing climate and energy policy in the United
States.

The solution to this issue is, of course, straightforward. Either
make the photographs where datasets are being used in research (i.e.
the HCN sites), available, or permit others to take them. Privacy
rules, such as not publishing the names and addresses of the observers,
should be made, however, the photographs themselves, viewing the site,
and views in the four orthogonal directions must be public. Volunteers
who are HCN Cooperative Observers need to either grant this permission
or not volunteer.

If you observe the state of climate science at all, you will know that any measurement (e.g. satellite or radiosonde temperature measurements) that conflict even the slightest with the main story line of anthropogenic global warming are subjected to intense and withering scrutiny.  Even the tiniest source of error or methodological sloppiness in these conflicting data sets cause global warming zealots to throw out the data as flawed.  It is instructive that perhaps the sloppiest data set of all is the surface climate measurement system they use primarily to support their case, and it is one they show absolutely no interest in scrutinizing, or letting anyone else scrutinize.

I am just finishing up my paper "A Skeptical Layman's Guide to Anthropogenic Global Warming," and one thing I encounter a lot with sources and websites that are strong supporters of Anthropogenic Global Warming (AGW) theory is that they will often say such-and-such argument by skeptics was just disproved by so-and-so. 

For example, skeptics often argue that historical temperature records do not correct enough for the effects of urbanization on long-term measurement points.  The IPCC, in fact, has taken the position that what is called the urban heat island effect is trivial, and does not account for much or any of measured warming over the last 100 years.  To this end, one of the pro-AGW sites (either RealClimate.org or the New Scientist, I can't remember which) said that "Parker in 2006 has disproved the urban heat island effect."

Now, if you were going to set out to do such a thing, how would you do it?  The logical way, to me, would be to draw a line from the center of the city to the rural areas surrounding it, and take a bunch of identical thermometers and have people record temperatures every couple of miles along this line.  Then you could draw a graph of temperature vs. nearness to the city center, and see what you would find.

Is that what Parker did?  Uh, no.  I turn it over to Steve McIntyre, one of the two men who helped highlight all the problems with the Mann hockey stick several years ago.

If you are not a climate scientist (or a realclimate reader), you
would almost certainly believe, from your own experience, that cities
are warmer than the surrounding countryside - the "urban heat island".
From that, it's easy to conclude that as cities become bigger and as
towns become cities and villages become towns, that there is a
widespread impact on urban records from changes in landscape, which
have to be considered before you can back out what portion is due to
increased GHG.

One of the main IPCC creeds is that the urban heat island effect has
a negligible impact on large-scale averages such as CRU or GISS. The
obvious way of proving this would seem to be taking measurements on an
urban transect and showing that there is no urban heat island. Of
course, Jones and his associates can't do that because such transects
always show a substantial urban heat island. So they have to resort to
indirect methods to provide evidence of "things unseen", such as Jones
et al 1990, which we've discussed in the past.

The newest entry in the theological literature is Parker (2004, 2006),
who, once again, does not show the absence of an urban heat island by
direct measurements, but purports to show the absence of an effect on
large-scale averages by showing that the temperature trends on calm
days is comparable to that on windy days. My first reaction to this,
and I'm sure that others had the same reaction was: well, so what? Why
would anyone interpret that as evidence one way or the other on UHI?

He goes on to take the study apart in detail, but I think most of you can see that the methodology makes absolutely zero sense unless one is desperately trying to toe the party line and win points with AGW supporters by finding some fig leaf to cover up this urban heat island problem.  By the way, plenty of people have performed the analysis the logical way we discussed first, and have shown huge heat island effects:

(Click for a larger view)

The bottom axis by the way is a "sky-view" metric I had not seen before, but is a measurement of urban topology.  Effectively the more urbanized and the more tall buildings around you that create a canyon effect, the lower the sky view fraction.  Note that no one gets a number for the Urban Heat Island effect less than 1 degree C, and many hover around 6 degrees (delta temperature from urban location to surrounding rural countryside).  Just a bit higher than the 0.2C assumed by the IPCC.  Why would they assume such a low number in the face of strong evidence?  Because assuming a higher number would reduce historical warming numbers, silly.

Oh, and the IPCC argues that the measurement points it uses around the world are all rural locations so urban heat island corrections are irrelevant.  Below are some sample photos of USHCN sites, which are these supposedly rural sites that are used in the official historical warming numbers.  By the way, these US sites are probably better than what you would find anywhere else in the world. (All pictures from surfacesations.org)  As always, you can click for a larger view.

You can help with the effort of documenting all the US Historical Climate Network (USHCN) stations.  See my post here -- I have already done two and its fun!

Since many advocates of anthropomorphic global warming theory have declared the twenty-year-old science to be "settled," then there must not be very much controversy or disagreement in the peer review reader comments to the UN's Fourth IPCC report.  Except, no one seems willing to publicize these comments.  Even US government organizations paid for by taxpayers.  Steve McIntyre is again having to resort to filing FOIA's to get the details of climate research.

Update: It appears that Congress is taking a similar approach to climate research when it comes to openness about earmarks.

Al Gore says that current global temperatures are the highest they have been in 1000 years.  A new study by the Institute of Astronomy in Zurich says that the "sun is more active now than it has been at anytime in the previous 1,000 years."  Related? 

Sunspots have been monitored on the Sun since 1610,
shortly after the invention of the telescope. They provide the
longest-running direct measurement of our star's activity.

The variation in sunspot numbers has revealed the Sun's 11-year cycle of activity as well as other, longer-term changes.

In particular, it has been noted that between about 1645 and 1715, few sunspots were seen on the Sun's surface.

This period is called the Maunder Minimum after the English astronomer who studied it.

It coincided with a spell of prolonged cold weather
often referred to as the "Little Ice Age". Solar scientists strongly
suspect there is a link between the two events - but the exact
mechanism remains elusive....

But the most striking feature, he says, is that
looking at the past 1,150 years the Sun has never been as active as it
has been during the past 60 years.

Over the past few hundred years, there has been a steady
increase in the numbers of sunspots, a trend that has accelerated in
the past century, just at the time when the Earth has been getting
warmer.

The data suggests that changing solar activity is influencing in some way the global climate causing the world to get warmer.

Of course, these poor scientists know that they could lose their jobs and be called Holocaust deniers if they don't acknowledge anthropomorphic global warming, so they do say:

Over the past 20 years, however, the number of
sunspots has remained roughly constant, yet the average temperature of
the Earth has continued to increase.

This is put down to a human-produced greenhouse effect caused by the combustion of fossil fuels.             (HT:  TJIC)

Which may actually be the case, but it is interesting that astronomers feel the need to say this without any evidence of such in their own study just to protect themselves from ostracism by the climate religionists.

However, even if the two are working in concert, the fact that solar activity explains some of the 20th century warming means that current climate models are WAY overestimating the impact of anthropomorphic warming. 

For example, the climate models in the current 2007 IPCC report assume that the world would have experienced no warming in the 20th century without man.  This is from Section 8, actual is the black line, the models without man are in blue, the models with man are in red:

In other words, the IPCC models completely ignore the increasing solar activity and assume 100% of 20th century warming was due to man-made effects, even the substantial warming before 1940 (and before the onset of truly heavy world-wide fossil fuel use).

Already, the models used by the IPCC tend to overestimate past warming even if all past warming is attributable to anthropomorphic causes.  If anthropomorphic effects explain only a fraction of past warming, then the current models are vastly overstated, good for stampeding the populous into otherwise unpopular political control over the economy, but of diminished scientific value.

Postscript: I cannot prove this, but I am willing to make a bet based on my long, long history of modeling (computers, not fashion).  My guess is that the blue band, representing climate without man-made effects, was not based on any real science but was instead a plug.  In other words, they took their models and actual temperatures and then said "what would the climate without man have to look like for our models to be correct."  There are at least four reasons I strongly suspect this to be true:

1. Every computer modeler in history has tried this trick to make their models of the future seem more credible.  I don't think the climate guys are immune.
2. There is no way their models, with our current state of knowledge about the climate, match reality that well. 
3. The first time they ran their models vs. history, they did not match at all.  This current close match is the result of a bunch of tweaking that has little impact on the model's predictive ability but forces it to match history better.  For example, early runs had the forecast run right up from the 1940 peak to temperatures way above what we see today.
4. The blue line totally ignores any of our other understandings about the changing climate, including the changing intensity of the sun.  It is conveniently exactly what is necessary to make the pink line match history.  In fact, against all evidence, note the blue band falls over the century.  This is because the models were pushing the temperature up faster than we have seen it rise historically, so the modelers needed a negative plug to make the numbers look nice.

I found this conjured up a terribly funny image in my mind.  JunkScience has a challenge to climate journalists to try the math to test for themselves whether current global warming estimates make any sense.  The challenge per se is not funny, but the picture of a journalist... well, read the challenge first:

We believe climate
models are programmed with excessive climate sensitivity based on a
flawed understanding of past ice ages. Moreover, climate models wrongly
magnify potential warming to accommodate positive feedback mechanisms
while comparison with empirical measure shows negative feedback dominates, reducing warming experienced to about half theoretical values.

The challenge is for you to actually check the numbers -- see for yourselves whether we are wrong or not. Look up Stefan's Constant or just use 5.67 x 10^-8
(close enough for our purpose but look it up to be sure). The textbook
derivation of globally averaged greenhouse, using Stefan's Constant,
evaluates to roughly 33 °C and 150 Wm^-2. The IPCC Third Assessment Report alt: Third Assessment Report (Equation 6.1) states: "The climate sensitivity parameter (global mean surface temperature response ΔT_s to the radiative forcing ΔF) is defined as: ΔT_s / ΔF = λ." A blackbody-equivalent Earth climate sensitivity parameter (λ) would be 33 / 150 = 0.22 °C per Wm^-2. Real world measures (here) indicate Earth responds with only half the efficiency of a blackbody with a lambda (λ) value of just 0.1 °C per Wm^-2.

Now use it to check the assertion: "Global climate forcing was about 6 1/2 W/m²
less than in the current interglacial period. This forcing maintains a
global temperature difference of 5 °C, implying a climate sensitivity
of 3/4 ± 1/4 °C per W/m²." Either consult your texts for Earth's temperature in Kelvin and any other numbers you need or see the numbers we've used here. Off you go -- we'll wait. If you can show us where we're wrong we'll retract and correct.

Can anyone out there picture your favorite journalist trying to do this?  Many journalists followed the tried-and-true career path of:  Avoid math altogether --> Become an English major --> Become a journalist as an alternative to playing the guitar in subway stations.  Who else would love to see Maureen Dowd taking on this analysis?

I finally watched the BBC special Global Warming Swindle and have to say that it presents a pretty good counter-hypothesis to the prevailing theory of anthropomorphic CO2 production to explain recent global temperature changes.  It also hits some good points on what might be motivating the hard core of the environmental movement beyond just concern about global warming, and why the costs of CO2 control are so high.

I have historically accepted the basic hypothesis of anthropomorphic global warming but have been skeptical of the exaggerated outcomes (Al Gore's 26 foot sea-level rise, for example, which is 17 times more than even the IPCC predicts over the next century) and have posited that a warmer but richer world may well be better than a cooler but poorer one.  I have also pointed out the uncertainties in the IPCC analysis that never get mentioned in the press, like the huge uncertainty in the feedback loops that drive much of the temperature change in current models.  For example, the IPCC admits they don't even know the sign of the largest feedback loop (clouds), which is a big uncertainty since about 2/3 or more of the warming in the models come not directly from CO2 but from these feedback loops.

Anyway, most of my past skepticism has been within the framework of these IPCC studies.  However, this documentary casts off the whole framework, offering a counter-hypothesis of solar activity to explain temperature variations.  I thought the most interesting part of the documentary was when they showed Al Gore from An Inconvenient Truth with a multi-thousand year plot of temperature and CO2.  The chart certainly looks compelling, but this movie makes the point that while the two lines move together, the CO2 line is lagging the temperature line by five hundred years.  Meaning that CO2 levels may be linked to temperature, but the causality may be opposite of that implied by Gore. 

The documentary goes on to offer solar activity as an alternative explanation, with graphs of moving curves of solar activity and temperature that seem to show at least as much correlation as Gore's CO2 graphs.  They hypothesize that rising temperatures driven by changes in solar
activity heat up oceans over time and cause them to release CO2 into
the atmosphere.  I don't think the evidence is definitive, but it certainly casts doubt as to whether we really know what is going on.  I always thought it a bit odd that people would search for the causes of changing temperatures without first checking out the sun, sortof like walking in a room that is too hot and trying to fix it without first checking the thermostat.  This is particularly true given new evidence that other planets are warming, presumably due to solar activity (unless, of course, it's an Exxon plot).

By the way:  Advocates of the anthropomorphic theory are criticizing this movie in part because it does not use Mann's hockey stick temperature chart.  Sorry, but if they want to claim the scientific high ground, I think they need to stop tying their argument to this weak study.  Statisticians have dumped on it repeatedly (apparently random white noise fed into their model produces a hockey stick) and the evidence for eliminating the Medieval warm period is based on the rings in one or two trees.

I promise, cross my heart, this is my last post on climate change for a while.  I thought my series of posts last week about the funny math of carbon offsets was the last, but Joe Miller at Catallarchy wrote something that caused me some introspection:

Just one caveat, though: I'm really, seriously, profoundly uninterested
in your skepticism about man-made global warming. Personally, I think
that the debate is just about as fruitful as a discussion of the
relative merits of evolution and Genesis as models of the origins of
the universe. It's called scientific consensus, people. You seem to
like it well enough for every other subject. And even if that
overwhelming scientific consensus turns out to be wrong, it's not like
a debate here is going to help with that. When scientists are wrong,
it's up to, you know, like, other actual scientists to settle
the question. A bunch of non-scientists googling studies that say what
we like them to say isn't accomplishing much, really.

Certainly I have always been in favor of facts and science over hysteria.  I criticized the rampant breast implant litigation in the face of science that showed no real long-term harms.  Ditto vaccinations.  So am I being a Luddite by, as an amateur, being skeptical of the scientific "consensus" on global warming?  Certainly climate change hawks want to paint my positions as "holocaust denial."  I had a few thoughts:

• For what it is worth, I have actually read much of the 2001 IPCC climate report (not the management summary, which is a worthless political document, but the report itself).  Courtesy of JunkScience.com, who has posted some of the 2007 report, I have read key parts of that report as well.  So I have at least informed myself beyond random Google searches.  My original university training was as a scientist, and later an engineer, though neither in climate (physics and mechanical engineering).
• The media has been known to declare a consensus ahead of its actual existence.  One example that comes to mind is a recent letter that a number of economists wrote supporting a Federal minimum wage increase, which much of the media spun into a "consensus" among economists that a minimum wage increase would be desirable and would not reduce employment.  I don't know Mr. Miller, but my bet is that some of the folks at Catallarchy might dispute this particular scientific consensus.
• To even imply that there is a single consensus on something as complex and multi-faceted as anthropomorphic global warming is facile.  I will take the movie "An Inconvenient Truth" as a fair representation of what the media perception of the consensus is  (the IPCC report actually does not agree in full, but we will get there in a minute).  Taking that movie as our straw man, the "consensus" or hypothesis is as follows:

1. The world has been warming for a century, and this warming is beyond any historical cycles we have seen over 1000 years  (ie, the hockey stick)
2. The last century's warming is almost all due to man's burning of fossil fuels and other releases of greenhouse gasses
3. In the next 100 years, CO2 produced by man will cause a lot more warming
4. Positive feedbacks in the climate, like increased humidity, will act to triple the warming from CO2
5. The bad effects of warming greatly outweigh the positive effects, and we are already seeing them today (polar bears dying, glaciers melting, etc)
6. These bad effects, or even a small risk of them, easily justify massive intervention today in reducing economic activity and greenhouse gas production

I believe this is a mostly fair representation of the media reporting of the scientific "consensus", with the exception that the media never really goes into step #4, and assigns all the blame for 6-8 degree temperature rise forecasts to CO2.  But this split between #3 and #4 is important to understand the science at all, and is included in the IPCC report, so I will make it. 

This is a complicated string of logic, with multiple assumptions.  I hope you see why declaring a scientific consensus on all points of this hypothesis is facile.  So where is there a scientific consensus on all of this?  My interpretation from the recent IPCC report and other sources is:

1. The world has been warming for a century, and this warming is beyond
   any historical cycles we have seen over 1000 years  (ie, the hockey
   stick)   There is a strong consensus on the first half.  We can argue about urban heat island corrections and ground vs. satellite all day, but the earth has pretty clearly warmed for a hundred years or so, after cooling before that.  The second half of the proposition is trickier.  The 2001 report relied on the Mann hockey stick to make the point that the 20th century is not just warmer but uniquely warmer.  I sense the 2007 report backing off this -- the Mann analysis has a lot of problems, and ongoing climate research continues to point to the great variability and cyclicallity of climate over time.  There is too much historical evidence, for example, of a warm middle ages for Mann to dismiss it with a few tree rings.
2. The last century's warming is almost all due to man's burning of fossil fuels and other releases of greenhouse gasses.   The 2001 IPCC report implied about half of the century's warming was man-made.  The new report seems to put more of the blame on man.  My sense is this will move over time back to half and half -- the evidence today of increased solar activity is becoming too strong to ignore as a cause along with man-made CO2.  However, I recognize right now that I am out of step with the IPCC and perhaps the "consensus" on this.
3. In the next 100 years, CO2 produced by man will cause a lot more warming.  CO2 production by man will cause more warming.  How much is the subject of models, which any economist or businessperson can tell you are notoriously flaky.  However, here is one fact that is part of the scientific consensus but you never hear in the media -- the relationship between atmospheric CO2 concentration and warming is a diminishing return.  In other words, the next doubling of CO2 in the atmosphere will have less impact on temperatures than the last doubling.  At some point, the effect of CO2 maxes out, and further increases in CO2 have no effect on temperatures.  My reading of the newest IPCC seems to imply that if the models predict about 6 degrees of warming over the next 100 years, of which about 2 is directly from CO2, while the rest are from positive feedbacks (discussed next)
4. Positive feedbacks in the climate, like increased humidity, will act to triple the warming from CO2.  OK, this strikes me as the key point in the scientific consensus.  Hypothesized positive feedback loops in the climate are what take the IPCC models from results that are warmer but probably manageable to results that appear catastrophically warmer.  Their models assume that as the world warms a bit from CO2, other effects take hold, and the world will warm even more.  For example, they posit that if the world is warmer, more water evaporates into water vapor in the atmosphere, which is a strong greenhouse gas, which accelerates the warming.  I think it is absurd to say there is a consensus on this point, which is adding 2/3 or more of the warming.  The notion of positive feedbacks in nature offends my intuition --  there are just not that many such processes in nature, or else nothing would be stable -- but then again Einstein's intution was offended by quantum mechanics and he was wrong.  However, using the IPCC's own findings (starting in section 8.6 here) the IPCC admits to there not even being a consensus on the sign (ie if it is positive or negative feedback) of what they describe as by far the strongest feedback process (cloud cover)!  I don't know how you can declare a consensus if you admit you don't even know the sign of the largest effect.
5. The bad effects of warming greatly outweigh the positive effects,
   and we are already seeing them today (polar bears dying, glaciers
   melting, etc)  It would be absurd to declare a consensus here because no one has really done much definitive work.   Most folks, including me, presume that since substantial warming would take us beyond the temperature range for which our bodies and our civilization has been adapted, the net effect would be bad.  But there are positive offsets to the negative effects (e.g. oceans rising) that you never really hear about in the press (longer growing season, for one) but which are in the IPCC report.  Climate scientists themselves have admitted there is no consensus on what effects that we are seeing today are due to warming.  Part of Antarctica (about 2%) shown in Al Gore's movie is warming, but most scientists now think that this may be due to cyclical variations in ocean currents, while most of Antarctica has actually been cooling of late.  Greenland is warming, but glaciers may not be receding as fast as once feared.  Polar bear populations, despite reports to the contrary, are increasing.
6. These bad effects, or even a small risk of them, easily justify
   massive intervention today in reducing economic activity and greenhouse
   gas production.  Many climate scientists express an opinion on this, often definitively, but if one argues that I am not qualified to test the consensus as a layman on global warming, then certainly climate scientists are far from qualified in drawing any conclusions on this topic.  The effects of a worldwide rollback on CO2 production at current technologies could be catastrophic, particularly for a billion people in India and China just on the verge of emerging from poverty.  Even in some of the most dire forecasts for warming, it is a very open question with little consensus as to whether a cooler but poorer world is better.  In fact, one can argue that even the pious Kyoto-signing countries are voting with their actions, rather than their words, on this issue, since they have resisted taking the hard economic steps necessary to meet their targets.

OK, that is more than I meant to write.  My point is that the word consensus is an absurd word to apply to the topic of anthropomorphic global warming.  Some things we understand pretty well (the world is warming, in part due to man-made CO2) and some we understand less well (the effect of feedback loops).  And some issues, like whether the harms from climate change are worth the cost of avoiding them, are entirely outside the purview of climate science.

Update: Strata-Sphere has a funny bit of related snark:

Global warming on Neptune's moon Triton as well as Jupiter and Pluto, and now Mars has some scratching their heads over what could possibly be in common with the warming of all these planets....

I still don't know. Could there be something in common with all the
planets in our solar system that might cause them all to warm at the
same time?

On a serious note, he has some nifty graphs of historic earth temperature reconstructions (including Mann) vs. sunspot activity reconstructions (sunspot activity generally being a proxy for solar output).  Short answer:  Sunspot activity at historical highs, at the same time as historical highs in temperature. 

When I was an undergraduate in physics, and later in engineering, we had this quaint process where we would conduct experiments and generate data, and from these results generate conclusions.

Climate science works differently.  First, political types and activists write the management summary in as alarming and as headlines-grabbing terms as they can, largely without the help or concurrence of the majority of the scientists involved in the study.  Then, they spend months modifying the underlying data, models, and scientific analysis to fit this management summary.

The summary of the most recent IPCC climate survey has already been released.  The body of the study, with the actual facts and models and stuff, has not been released (won't be for months) and carries this warning on the last draft:

"Changes (other than
grammatical or minor editorial changes) made after acceptance by the
Working Group or the Panel shall be those necessary to ensure
consistency with the Summary for Policymakers or the Overview Chapter."

Its probably time for another once-every-six-months update on global warming.  In this post I will address the current leading climate intervention position, which is:  Even if we don't understand global warming fully, the time to take massive action is now, before the process builds momentum (similar to the notion that it is easier to deflect a meteor away from earth when it is millions of miles away, rather than right on top of us).  The potential downside of global warming, it is argued, is too high to justify waiting until we are sure.   

While I find arguments that attempt to challenge the current global warming orthodoxy in any way tends to get one labeled a Luddite not worth listening to, giving one the feeling of being a southern Baptist advocating creationism in a room full of Massachusetts Democrats, I will once again try to refute this need to immediate and massive intervention.

The shorthand I use for my argument against intervention is "creating a cooler but poorer world".  In a nutshell, given current technology and likely government intervention approaches, slowing global warming almost certainly entails slowing world growth.  And while the true cost of warming is poorly understood, the true cost of reduced world economic growth is very well understood and is very high.  The real question, then, is do we understand global warming and its potential downsides enough to believe that curbing them outweighs the almost certain negative impact from a poorer world.

I will begin by conceding some warming

Typically when making this argument, I will concede some man-made global warming.  It is hard to refute the fact from various CO2 concentration estimates that man has increased the amount of CO2 in the atmosphere over the last 50 years, and that this CO2 likely has had and will have some impact on global temperatures.  As a result, I am willing to concede a degree or two of warming from man-made effects over the next century.  This is lower than most of the warming estimates that you see in the press, but scientists will have to nail down a lot more issues before they can convince me these higher numbers are correct.  Some of these issues include:

• World temperatures rose by a half degree in the first half of the 20th century through mostly natural phenomena.  No one knows why (though solar activity may help explain it), but even global warming's strongest supporters agree that it was probably not due to man.  No one can therefore with any accuracy separate warming in the late 20th century due to this natural effect and warming due to man's impact.  Check out Mann's now-famous hockey stick below:

Global warming advocates love this chart - I mean this is their chart, not the skeptics' - and it probably plays well with non-scientific editors who are believers themselves, but I sure wouldn't want to defend this in a board room.  What if this were a sales chart, and I wanted to claim that the sales increase after I started work in 1950 was all due to my effort.  I can just see my old boss Chuck Knight at Emerson, or maybe Larry Bossidy at AlliedSignal, saying - "well Warren, it sure looks like things changed in 1900, not 1950.  And whatever was driving things up from 1900 to 1950, why do you think that that effect, which you can't explain, suddenly stopped and your influence took over.  And by the way, why did you end your chart with 1998 - I seem to remember 1998 was the peak.  Isn't it kind of disingenuous to leave off the last 6 years when the numbers came back down some?" (update:  Even in the arctic, where the media writes with so much confidence that global warming is having a measurable impact, the difference between cyclical variations and man-made effects is hard to unravel.)

• No one really understands the cyclical variations in world temperatures and climate.  I think it is large, and certainly there are historical records of the last 800 years that seem to point to climactic extremes.  Mann, et. al. claim to have shown that man's effects dwarf these natural variations with their 1000-year hockey stick, but there are a lot of problems with Mann, not the least of which is his unbelievably suspicious refusal to release his data and methodology to the scientific community, behavior that would not be tolerated of any other scientist except one who supported the global warming consensus view.
• It is still not clear that the urban heat island effect has been fixed in the ground data, so satellite data tends to show less warming (but some none-the-less).
• The climate models are absurd in ways even a non-climatologist can figure out.  For example, economies in energy inefficient undeveloped nations are assumed to grow like crazy in the IPCC scenarios, such that "then the average income of South Africans will have overtaken that of
  Americans by a very wide margin by the end of the century. Because of
  this economic error, the IPCC scenarios of the future also suggest that
  relatively poor developing countries such as Algeria, Argentina, Libya,
  Turkey, and North Korea will all surpass the United States."
• I no longer trust the scientific community on global warming.  This quote from National Center for Atmospheric Research (NOAA) researcher and global warming action promoter, Steven Schneidersays it all:

We have to offer up scary scenarios, make simplified, dramatic
statements, and make little mention of any doubts we have. Each of us
has to decide what the right balance is between being effective and
being honest.

While many serious scientists are working on the issue, 100% of the anti-growth, anti-technology, anti-America, and anti-man folks have jumped strongly on the global warming bandwagon, and many of these folks have in fact grabbed the reins, leading major efforts and groups.  It is important to note that these folks do not care about scientific accuracy or facts.  Their agenda is completely and absolutely to use global warming as their lead issue to push their anti-growth agenda.  As such, none of these folks are going to tolerate any fact, study, or scientific voice that in any way questions the global warming orthodoxy.  And can any scientist be considered serious who uttered the following statement (from the UN's IPCC Conference Summary, page 2):

"It is
likely that, in the Northern Hemisphere, ... 1998 [was] the warmest year during the past thousand years."

My physics instructors in college used to criticize us students constantly for not understanding the error range in our lab work.  I wonder what they would think of a group of scientists that stated with confidence that 1998 was the warmest year in the last one thousand, when they only have direct measurement for the last 100 years or so and even then over only a small percentage of the planet and the other 900 years are estimated from tree rings and ice cores.  I am tired of being criticized as a Luddite for challenging "scientists" who think they know with confidence the exact world temperature since Charlemagne. 

Anyway, to avoid getting bogged down in this mess, I am willing to posit some man-made warming, say 1-2 degrees over the next 100 years.  For most who argue the subject, this is the end of the discussion.  For me, it is just the beginning.

What impact, warming?

Beyond bad cinema and Sunday supplement hyperbole, its difficult to find the good science aimed at quantifying the impacts, positive and negative, from global warming.  In fact, it is impossible in any venue at any level of quality to find any mention of the positive impacts of warming, though anyone with half a brain can imagine any number of positive impacts (e.g. longer growing seasons in cold climates) that will at least partially offset warming negatives.

Now, I am sure many scientists would respond that climate is complicated, and its hard to judge what will happen.  Which I believe is true.  But surely the same scientists that can cay that the world will warm by x degrees with enough certainty to demand that billions or even trillions of dollars be spent to change energy use should be able to come to some conclusions about the net effects, both positive and negative, from warming.

Certainly sea levels will probably rise, as some ice caps melt, by maybe a foot in the consensus view.  And storms and hurricanes may get worse, though its hard to separate the warming effect from the natural cyclical variation in hurricane strength, at least in the Atlantic.  What does seem to be clear is that the warming disproportionately will occur in colder, drier climates.  For example, a large part of the world's warming will occur in Siberia. 

When I hear this, I immediately think longer growing seasons in cold climates plus less impact in already warm climates = more food worldwide.  It strikes me that since the climate models tend to spit out warming not only world wide but by area of the world, it would be fairly easy to translate this into an estimate of net impact on food production.  This seems to be such an obvious area of study that I can only assume it has been done, and, since we have not heard about it, that the answer from global warming was "increased food production".  Since this conclusion neither supports scary headlines, increased grant money, or the anti-growth agenda, no one really talks about it or studies it much.  I would bet that if I took all the studies and grants today aimed at quantifying the impact of global warming, more than 95% of the work, maybe 100% of the work, would be aimed solely at negative impacts, studiously ignoring any positive counter-veiling effects.

I often get looks from global warming advocates like I am from Mars when I suggest work needs to be done to figure out how bad warming is, or even if it is really that bad at all.  I have learned that there are typically two reasons for this reaction:

1. I am talking to one of the anti-growth types, for whom the global warming issue is but a means to the end of growth limitation.  These folks need global warming to be BAD as a fundamental premise, not as something that can be fact-checked.  They cannot have people questioning that global warming is the ultimate bad thing that trumps everything else anymore than the Catholic Church can have folks start to question the fallibility of the Pope.
2. I am talking to an environmentalists who considers man's impact impact on earth as bad, period.  It is almost an aesthetic point of view, that it is fundamentally upsetting to see man changing the earth in such a measurable way, irregardless of whether the change affects man negatively.  These are the same folks with whom you cannot argue about caribou in ANWR.  They don't oppose ANWR drilling because they honestly think the caribou will be hurt, but because they like the notion that there is a bunch of land somewhere that man is not touching

By the way, though I know this will really mark me as an environmental Luddite, does anyone really believe that in 100 years, if we've really screwed ourselves by making things too hot, that we couldn't find a drastic way to cool the place off?  Krakatoa's eruption put enough dust in the air to cool the world for a decade.  The world, unfortunately, has a lot of devices that go bang laying around that I bet we could employ to good effect if we needed to put some dust in the stratosphere to cool ourselves off.  Yeah, I am sure that there are hidden problems here but isn't it interesting that NO ONE in global warming, inc. ever discusses any option for solving warming except shutting down the world's economies?

What impact, Intervention?

While the Kyoto treaty was a massively-flawed document, with current technologies a Kyoto type cap and trade approach is about the only way we have available to slow or halt CO2 emissions.  And, unlike the impact of warming on the world, the impact of such a intervention is very well understood by the world's economists and seldom in fact disputed by global warming advocates.  Capping world CO2 production would by definition cap world economic growth at the rate of energy efficiency growth, a number at least two points below projected real economic growth.  In addition, investment would shift from microprocessors and consumer products and new drug research and even other types of pollution control to energy. The effects of two points or more lower economic growth over 50-100 years can be devastating:

• Currently, there are perhaps a billion people, mostly in Asia, poised to exit millenia of subsistence poverty and reach the middle class.  Global warming intervention will likely consign these folks to continued poverty.  Does anyone remember that old ethics problem, the one about having a button that every time you pushed it, you got a thousand dollars but someone in China died.  Global warming intervention strikes me as a similar issue - intellectuals in the west feel better about man being in harmony with the earth but a billion Asians get locked into poverty.
• Lower world economic growth will in turn considerably shorten the lives of billions of the world's poor
• A poorer world is more vulnerable to natural disasters
• The unprecedented progress the world is experiencing in slowing birth rates, due entirely to rising wealth, will likely be reversed.  A cooler world will not only be poorer, but likely more populous as well.  It will also be a hungrier world, particularly if a cooler world does indeed result in lower food production than a warmer world
• A transformation to a prosperous middle class in Asia will make the world a much safer and more stable place, particularly vs. a cooler world with a billion Asian poor people who know that their march to progress was halted by western meddling.
• A cooler world would ironically likely be an environmentally messier world.  While anti-growth folks blame all environmental messes on progress, the fact is that environmental impact is a sort of inverted parabola when plotted against growth.  Early industrial growth tends to pollute things up, but further growth and wealth provides the resources and technology to clean things up.  The US was a cleaner place in 1970 than in 1900, and a cleaner place today than in 1970.  Stopping or drastically slowing worldwide growth would lock much of the developing world, countries like Brazil and China and Indonesia, into the top end of the parabola.  Is Brazil, for example, more likely to burn up its rain forest if it is poor or rich?

The Commons Blog links to this study by Indur Goklany on just this topic:

If global warming is real and its effects will one day be as devastating as
some believe is likely, then greater economic growth would, by increasing
greenhouse gas (GHG) emissions, sooner or later lead to greater damages from
climate change. On the other hand, by increasing wealth, technological
development and human capital, economic growth would broadly increase human
well-being, and society's capacity to reduce climate change damages via
adaptation or mitigation. Hence, the conundrum: at what point in the future
would the benefits of a richer and more technologically advanced world be
canceled out by the costs of a warmer world?

Indur Goklany attempted to shed light on this conundrum in a recent paper
presented at the 25th Annual North American Conference of the US Association for
Energy Economics, in Denver (Sept. 21, 2005). His paper "” "Is a
richer-but-warmer world better than poorer-but-cooler worlds?" "” which can
be found here, draws
upon the results of a series of UK Government-sponsored studies which employed
the IPCC's emissions scenarios to project future climate change between 1990 and
2100 and its global impacts on various climate-sensitive determinants of human
and environmental well-being (such as malaria, hunger, water shortage, coastal
flooding, and habitat loss). The results indicate that notwithstanding climate
change, through much of this century, human well-being is likely to be highest
in the richest-but-warmest world and lower in poorer-but-cooler worlds. With
respect to environmental well-being, matters may be best under the former world
for some critical environmental indicators through 2085-2100, but not
necessarily for others.

This conclusion casts doubt on a key premise implicit in all calls to take
actions now that would go beyond "no-regret" policies in order to reduce GHG
emissions in the near term, namely, a richer-but-warmer world will, before too
long, necessarily be worse for the globe than a poorer-but-cooler world. But the
above analysis suggests this is unlikely to happen, at least until after the
2085-2100 period.

Policy Alternatives

Above, we looked at the effect of a cap and trade scheme, which would have about the same effect as some type of carbon tax.  This is the best possible approach, if an interventionist approach is taken.  Any other is worse.

The primary other alternative bandied about by scientists is some type of alternative energy Manhattan project.  This can only be a disaster.   Many scientists are technocratic fascists at heart, and are convinced that if only they could run the economy or some part of it, instead of relying on this messy bottom-up spontaneous order we call the marketplace, things, well, would be better.  The problem is that scientists, no matter how smart they are, miss with their bets because the economy, and thus the lowest cost approach to less CO2 production, is too complicated for anyone to understand or manage.  And even if the scientists stumbled on the right approaches, the political process would just screw the solution up.  Probably the number one alternative energy program in the US is ethanol subsidies, which are scientifically insane since ethanol actually increases rather than reduces fossil fuel consumption.  Political subsidies almost always lead to investments tailored just to capture the subsidy, that do little to solve the underlying problem.  In Arizona, we have thousands of cars with subsidized conversions to engines that burn multiple fuels but never burn anything but gasoline.  In California, there are hundreds of massive windmills that never turn, having already served their purpose to capture a subsidy.  In California, the state bent over backwards to encourage electric cars, but in fact a different technology, the hybrid, has taken off.

Besides, when has this government led technology revolution approach ever worked?  I would say twice - once for the Atomic bomb and the second time to get to the moon.  And what did either get us?  The first got us something I am not sure we even should want, with very little carryover into the civilian world.  The second got us a big scientific dead end, and probably set back our space efforts by getting us to the moon 30 years or so before we were really ready to do something about it or follow up the efforts.

If we must intervene to limit CO2, we should jack up the price of fossil fuels with taxes, or institute a cap and trade scheme which will result in about the same price increase, and the market through millions of individual efforts will find the lowest cost net way to reach whatever energy consumption level you want with the least possible cost.  (The only real current alternative that is rapidly deploy-able to reduce CO2 emissions anyway is nuclear power, which could be a solution but was killed by...the very people now wailing about global warming.)

Conclusion

I would like to see some real quality discussion as to the relative merits of the path the world is on today vs. an interventionist world that is cooler but poorer, more populous, hungrier, and less politically stable.  If anyone knows of some thoughtful work in this area, please leave a link in the comment area or in my email.

By the way, I got through this whole post without mentioning or quoting Bjorn Lomborg, which really is not fair since he has been very eloquent about just this cooler but poorer argument, but since he is treated like the anti-Christ by global warming believers, it generally only causes people to stop listening when you mention him.

Note finally that other past articles in this series can be found here and here and here.

Disclosure:   I am not funded in any way by the automobile or electric power industry. In fact, my personal business
actually benefits from higher oil prices, since our recreation sites
tend to be near-to-home alternatives for those who can't afford to
drive across country, so global warming intervention would probably help me in the near term.  However, I do own a fair amount of Exxon-Mobil stock, so you may assume that all my opinions are tainted, following the tried and true Global Warming formula that any money from the energy industry is automatically tainting, but incentives that tie grant money, recognition, or press exposure to the magnitude of warming a scientist predicts never carry a taint.  My opinions carry with them an honest concern for the well-being of non-Americans, like the Chinese, which I'm told used to be considered a liberal value until liberals and progressives decided more recently that they actually fear and oppose economic growth in places like China.