Humanmade Pollutants May Be Driving Earth's Tropical Belt Expansion: May Impact Large-Scale Atmospheric Circulation

http://www.sciencedaily.com/releases/2012/05/120516140004.htm

cienceDaily (May 16, 2012) — Black carbon aerosols and tropospheric ozone, both humanmade pollutants emitted predominantly in the Northern Hemisphere's low- to mid-latitudes, are most likely pushing the boundary of the tropics further poleward in that hemisphere, new research by a team of scientists shows.

While stratospheric ozone depletion has already been shown to be the primary driver of the expansion of the tropics in the Southern Hemisphere, the researchers are the first to report that black carbon and tropospheric ozone are the most likely primary drivers of the tropical expansion observed in the Northern Hemisphere.