I am on the Union of Concerned Scientists mailing list for their Sound Science Initiative. Today I got a Global Warming update that discusses an aspect of global warming measurements that pretty much ends the debate on whether temperatures are actually rising. The gist of the debate is whether surface or tropospheric measurements are more accurate because these two measurements disagree as to whether temperatures are rising. You have probably mostly seen the dramatic rise in surface tempuratures. Satellite measurements have shown far less warming in the troposhere even though models suggest that the surface and troposphere should pretty much warm together. Obviously, the right wing oil whores have seized on this to claim global warming is still not known to be really happening.
Reinterpretation of the data has solved this by realizing that the interpretation of the tropospheric temperatures were inaccurate. To quote below the break:
"Only recently has this puzzle been largely resolved. Recent work by Fu et al. (2004a) reveals a systematic oversight in previous analytic procedures -- an oversight that did not account for the inclusion of cooler stratospheric (atmospheric layer above the troposphere to about 50 km) temperatures in data from a satellite sensor targeted for the troposphere. Reinterpretation of the satellite data after correction for this sensor feature shows that during the period 1979-2001, global mean tropospheric temperatures rose at a rate close to that of the surface temperatures, in good agreement with predictions of climate models."
I will skip over some details which I can forwad to folks who really want (or you can sign up for SSI updates on the Union of Concerned Scientists website).
Here are the conclusions:
"The apparent discrepancy between measured and predicted tropospheric air temperature trends-and the corollary discrepancy between measured surface temperature and tropospheric air temperature trends-has been a major justification for those skeptical of heat-trapping gas-induced surface warming and has been often interpreted to mean that either the surface temperature records are wrong and/or that there must be important and robust heat transfer processes in the atmosphere that are not well represented in climate models. That there is now a close correspondence of model predictions with the late 20th century air temperature trends increases our confidence in the physical realism of the models."
I am sure Rush "Gimme Drugs" Limbaugh and the like will continue to claim that global warming is unproven (much like many say that evolution is unproven). But remember Rush also claims that volcanos explain warming. His claim about the Pinatubo eruption being what is to blame for recent warming was a.) based on a 10-fold exaggeration in the amount of carbon expelled from the volcano which he maintained even after being corrected; b.) ignores the fact that volcanic eruptions will cause global COOLING in the short term because the carbon it puts out is mainly particulate rather than CO2 so it blocks incoming rather than reflected heat; and c.) that the carbon that volcanos put into the air, being particulate rather than CO2, settles OUT of the air on a clearly understood schedule. So the volcano myth has long ago been debunked. Now the measurement discrepancy has been solved.
Finally, the Bush/Rush claim that atmospheric scientists disagree on global warming. This is misleading. Yes you can find some scientists who disagree with the models, BUT it is a ration of about 10:1 in favor of oil-emissions caused warming being true. Those who disagree are mostly either grand standers or paid by the oil industry. So some 90% of scientists AGREE that global warming is happening and that WE are responsible.
This scientific moment brought to you by the Union of Concerned Scientists (channeled by me):
http://www.ucsusa.org