David Kirkpatrick

January 29, 2010

There’s a joker in the global warming deck

Filed under: Politics, Science — Tags: , , , , — David Kirkpatrick @ 12:23 am

And surprisingly it’s stratospheric water vapor. Water vapor in a thin wedge of the upper atmosphere seems to have a strong effect on surface temperatures, and might be the explanation for both the rapid rise of the 1990s and subsequent dire predictions for global temperature in the short term. All the more reason to let science do its job of reasoned skepticism, and not turn into political dogma.

From the first link:

Water vapor is a highly variable gas and has long been recognized as an important player in the cocktail of greenhouse gases — carbon dioxide, methane, halocarbons, nitrous oxide, and others — that affect climate.

“Current  do a remarkable job on water vapor near the surface. But this is different — it’s a thin wedge of the  that packs a wallop from one decade to the next in a way we didn’t expect,” says Susan Solomon, NOAA senior scientist and first author of the study.

Since 2000, water vapor in the stratosphere decreased by about 10 percent. The reason for the recent decline in water vapor is unknown. The new study used calculations and models to show that the cooling from this change caused surface temperatures to increase about 25 percent more slowly than they would have otherwise, due only to the increases in  and other greenhouse gases.

An increase in stratospheric water vapor in the 1990s likely had the opposite effect of increasing the rate of warming observed during that time by about 30 percent, the authors found.