Coyote Blog

I know I hammer this home constantly, but it is often worth a reminder.  The issue in the scientific debate over catastrophic man-made global warming theory is not whether CO2 is a greenhouse gas, or even the approximate magnitude of warming from CO2 directly, but around feedbacks.   Patrick Moore, Greenpeace founder, said it very well:

What most people don't realize, partly because the media never explains it, is that there is no dispute over whether CO2 is a greenhouse gas, and all else being equal would result in a warming of the climate. The fundamental dispute is about water in the atmosphere, either in the form of water vapour (a gas) or clouds (water in liquid form). It is generally accepted that a warmer climate will result in more water evaporating from the land and sea and therefore resulting in a higher level of water in the atmosphere, partly because the warmer the air is the more water it can hold. All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone.

Many scientists do not agree with this, or do not agree that we know enough about the impact of increased water to predict the outcome. Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover. It all depends on how much, and a t what altitudes, latitudes and times of day that water is in the form of a gas (vapour) or a liquid (clouds). So if  a certain increase in CO2 would theoretically cause a 1.0C increase in temperature, then if water caused a 3-4 times positive feedback the temperature would actually increase by 3-4C. This is why the warming predicted by the models is so large. Whereas if there was a negative feedback of 0.5 times then the temperature would only rise 0.5C.

My slightly lengthier discussions of this same issue are here and here.

A while back I suggested, part tongue-in-cheek:

Once trees hit their maturity, their growth slows and therefore the
rate they sequester CO2 slows.  At this point, we need to be cutting
more down, not less, and burying them in the ground, either as logs or
paper or whatever.  Just growing forests is not enough, because old
trees fall over and rot and give up their carbon as CO2.  We have to
bury them.   Right?

Now, Greenpeace co-founder Patrick Moore writes:

There is a misconception that cutting down an old tree will result
in a net release of carbon. Yet wooden furniture made in the
Elizabethan era still holds the carbon fixed hundreds of years ago.

Berman,
a veteran of the forestry protest movement, should by now have learned
that young forests outperform old growth in carbon sequestration.

Although
old trees contain huge amounts of carbon, their rate of sequestration
has slowed to a near halt. A young tree, although it contains little
fixed carbon, pulls CO2 from the atmosphere at a much faster rate.

When a tree rots or burns, the carbon contained in the wood is released back to the atmosphere....

To address climate change, we must use more wood, not less. Using wood
sends a signal to the marketplace to grow more trees and to produce
more wood. That means we can then use less concrete, steel and plastic
-- heavy carbon emitters through their production. Trees are the only
abundant, biodegradable and renewable global resource.