NPR:Fresh Air:Terry Gross:Tim Flannery - caught a bit of the interview. The amount of greehouse gases we've put into the atmosphere should be causing a lot more warming than is observed. What is masking it?
1. After 9/11, all commercial airplanes were grounded for two days over the US, and climatologists had a unique chance to study the effect of airplane con-trails on the weather (if not climate). Well, we are told that the surface temperature rose by 2 degrees. Apparently, airplane exhaust helps seed cirrus clouds, which reflect sunlight and reduce the effect of the carbon dioxide we've put into the atmosphere.
2. The dirty coal burned by China produces a lot of sulphur dioxide and particulate matter that also serves to mask the warming. As China deploys cleaner coal-burning technology, (for reasons of the respiratory health of its population, if nothing else), the masking effect will go away.
So, to mitigate global warming it seems you should try to max. your frequent flier miles, and burn poor quality coal in your fireplace. :)
On the other hand, aluminum foil is a good reflector. Maybe if we wrap all the GW-deniers in foil, that'd work too!