Carnegie study finds climate impact of particulates varies greatly depending on where the pollution originated - Green Car Congress
Aerosols are tiny particles released into the atmosphere by human activities; they have proven negative effects on air quality—damaging human health and agricultural productivity. However, while greenhouse gases cause warming by trapping heat in the atmosphere, some aerosols can have a cooling effect on the climate because the aerosol particles cause more of the sun’s light to be reflected away from the planet. Estimates indicate that aerosols have offset about a third of greenhouse gas-driven warming since the 1950s.