Posts tagged ‘UHI’

Some Responsible Press Coverage of Record Temperatures

The Phoenix New Times blog had a fairly remarkable story on a record-hot Phoenix summer.  The core of the article is a chart from the NOAA.  There are three things to notice in it:

  • The article actually acknowledges that higher temperatures were due to higher night-time lows rather than higher daytime highs  Any mention of this is exceedingly rare in media stories on temperatures, perhaps because the idea of a higher low is confusing to communicate
  • It actually attributes urban warming to the urban heat island effect
  • It makes no mention of global warming

Here is the graphic:



This puts me in the odd role of switching sides, so to speak, and observing that greenhouse warming could very likely manifest itself as rising nighttime lows (rather than rising daytime highs).  I can only assume the surrounding area of Arizona did not see the same sort of records, which would support the theory that this is a UHI effect.

Phoenix has a huge urban heat island effect, which my son actually measured.  At 9-10 in the evening, we measured a temperature differential of 8-12F from city center to rural areas outside the city.  By the way, this is a fabulous science fair project if you know a junior high or high school student trying to do something different than growing bean plants under different color lights.

Phil Jones Hoping for Warming

I feel the need to reproduce this email in its entirety.  Here is Phil Jones actively hoping the world will warm (an outcome he has publicly stated would be catastrophic).  The tribalism has gotten so intense that it is more important for his alarmist tribe to count coup on the skeptics than to hope for a good outcome for the Earth.

>From: Phil Jones []
>Sent: 05 January 2009 16:18
>To: Johns, Tim; Folland, Chris
>Cc: Smith, Doug; Johns, Tim
>Subject: Re: FW: Temperatures in 2009
>   Tim, Chris,
>     I hope you're not right about the lack of warming lasting
>   till about 2020. I'd rather hoped to see the earlier Met Office
>   press release with Doug's paper that said something like -
>   half the years to 2014 would exceed the warmest year currently on
> record, 1998!
>     Still a way to go before 2014.
>     I seem to be getting an email a week from skeptics saying
>   where's the warming gone. I know the warming is on the decadal
>   scale, but it would be nice to wear their smug grins away.
>     Chris - I presume the Met Office
> continually monitor the weather forecasts.
>    Maybe because I'm in my 50s, but the language used in the forecasts seems
>    a bit over the top re the cold. Where I've been for the last 20
> days (in Norfolk)
>    it doesn't seem to have been as cold as the forecasts.
>     I've just submitted a paper on the UHI for London - it is 1.6 deg
> C for the LWC.
>   It comes out to 2.6 deg C for night-time minimums. The BBC forecasts has
>   the countryside 5-6 deg C cooler than city centres on recent nights.
> The paper
>   shows the UHI hasn't got any worse since 1901 (based on St James Park
>   and Rothamsted).
>   Cheers
>   Phil

Is this better or worse than rooting for a bad economy to get your favorite politicians elected?  Anthony Watt has more in this same tone, showing how climate scientists were working to shift messages and invent new science to protect the warming hypothesis.

The last part about the UHI (urban heat island) study is interesting.  I don't remember this study.  But it is interesting that he accepts a UHI of as high as 1.6C (my son and I found evening UHI in Phoenix around 4-6C, about in line with his London results).    It looks like he is trying to say that UHI should not matter to temperature measurement, since it has not changed in London since 1900  (a bias in temperature measurement that does not change does not affect the temperature anomaly, which is what tends to be important).  But the point is that many other temperature stations in the Hadley CRUT data base are in cities that are now large today but were much smaller than London in 1900 (Tucson is a great example).  In these cases, there is a changing measurement bias that can affect the anomaly, so I am not sure what Jones was trying to get at.

Correlation in Political Views

(via Popehat) one of the writers at Balloon Juice offers this test of a "reasonable" Conservative blog

1) Do you believe in evolution?

2) Do you believe that the average temperature on earth has increased over the past 30 years?

A few semi-random thoughts:

  • Count me as a yes for both
  • Is the best test of the likely reasonableness of a political blog really to ask two questions about science that such a blog might never even touch?  This is not an entirely rhetorical question -- just the other day I linked the data that suggested that asking your date about beer might be the best way to test their views on sex.  Sometimes odd cross-correlations exist, but I don't think these would be my first test
  • I find the Left's obsession with evolution as a litmus test for political thought to be funny, as the theory of evolution is largely irrelevant to any political questions except fairly narrowly the question of teaching evolution in schools.   I find it funny as much of the Left does not believe in a science - micro economics (very specifically differentiated from macro) - that is also fairly old and well understood and is much more relevant to typical political blog discourse.  I had a debate on national TV a few weeks ago with a man who claimed, as many on the Left will, that raising the minimum wage will increase employment.   If we want to test blogs based on scientific questions, why wouldn't a far more relevant question in public discourse be "do you believe demand curves slope down" or perhaps something like "do you believe breaking windows stimulates the economy?"
  • The second test is not a bad test of any site writing about global warming and climate change.  I don't know many science-based skeptics who would deny that global temperatures have likely increased over the last 30 years  (from a data base without UHI or alarmist manual adjustments or large data holes, the trend is something like 0.1C per decade).   I say "likely" because it could be argued that 0.1C is within the error bar of the measurement. Even so, this wouldn't be my first test, even for climate sites
  • I would tend to have four tests of the liberal and conservative sites I read
    • Is it interesting to read (after all, this is a freaking unpaid hobby)
    • Is the data-analysis-to-name-calling ratio fairly high
    • Are they willing to step out of team politics and question their own team from time to time
    • Do they have interesting perspectives on individual liberty.  I can plow through Marxist economic posts on progressive sites if from time to time they have a useful perspective on, say, indefinite detentions or gay marriage.  I can plow through some social Conservatism if they have useful posts on economics and fiscal policy.

This post from Nick Gillespie is sort of relevent, in which he talks about CPAC and social conservatives.  One line that struck me

A person's choice of sexual partner in no way means he or she can't be in favor of less spending on farm subsidies.

If I weeded out every blog that held some sort of view with which I disagree (or might even call "unreasonable") I would be down to about 3 blogs in my reader.

Urban Heat Islands

For most city dwellers, the temperature increase in the summer time from the urban heat island effect (UHIE) dwarfs any temperature increase from global warming.  UHIE is the result of high population density, with lots of cars and equipment that generate heat and buildings and roads that seem to hold it in.  Many cities are several degrees warmer than the surrounding countryside.  The effect is so dramatic that correcting for this effect is a big part of the uncertainty in answering seemingly simple questions like "how much has the earth warmed in the last 100 years?"

Apparently, UHIE is a big problem in one of the world's densest cities, Tokyo.

The gleaming high rise buildings that crowd the
cityscape may symbolize Japan's economic recovery but they have also
converted this priciest of human habitats into vast heat-trapping
canyons in what is known as the urban heat island (UHI) effect.

Heat churned out by air-conditioners, automobiles and human activity
finds no escape, causing ambient temperatures, especially in the summer
months, to rise by several degrees and forcing authorities to
constantly look for newer ways to cool down a city on the boil....

A report released by the Tokyo Metropolitan government this
year shows that average temperature rise in the capital over the course
of the 20th century has been 3 degrees C....

Yamaguchi also told IPS that the number of days recording temperatures
of over 35 degrees C has gone up to more than 35 days a year,
concentrated around the three summer months between July and September.
That contrasts with the 14 days recorded in 1975....

Tellingly, most of the deaths from the European heat wave several years
ago where in cities, which tells me that UHIE had a contributing role
more than global warming.  This is actually something we argue about
from time to time in Phoenix.  Ocasionally the city considers
steps to lower our albedo, such as requiring white (rather than black)
roofs and looking at alternatives to dark asphalt for roads.

This has never been a big environmentalist issue.  My guess is that
this is because environmentalists, at least in the US, have adopted a
goal of increasing urban concentration and population densities
.  I
suppose it might be embarassing for them to admit the warming they are
trying to get city dwellers to blame on CO2 may in fact be largely due
to the environmentalists own urban planning approaches.