Interesting new research from NASA shows that aerosols play a much bigger part in Arctic warming than was previously thought:
Though greenhouse gases are invariably at the center of discussions about global climate change, new NASA research suggests that much of the atmospheric warming observed in the Arctic since 1976 may be due to changes in tiny airborne particles called aerosols.
Emitted by natural and human sources, aerosols can directly influence climate by reflecting or absorbing the sun’s radiation. The small particles also affect climate indirectly by seeding clouds and changing cloud properties, such as reflectivity.
Since decreasing amounts of sulfates and increasing amounts of black carbon both encourage warming, temperature increases can be especially rapid. The build-up of aerosols also triggers positive feedback cycles that further accelerate warming as snow and ice cover retreat.
In the Antarctic, in contrast, the impact of sulfates and black carbon is minimized because of the continent’s isolation from major population centers and the emissions they produce.
“There’s a tendency to think of aerosols as small players, but they’re not,” said Shindell. “Right now, in the mid-latitudes of the Northern Hemisphere and in the Arctic, the impact of aerosols is just as strong as that of the greenhouse gases.”
All models are wrong. Some are just more useful than others. This new research will make the useful climate models we have even better. It also points to a man-made pollutant that is both much easier to do something about, and which can have an impact on our perilous climate change trajectory.
I have already read a couple of blog posts that claim that this disproves global warming is really happening, and another that says carbon dioxide is off the hook so we should stop worrying about it. I hope people will read the full NASA release.