Nature Geosci. 2, 294–300 (2009)

Aerosols such as soot and sulphates have a significant influence on climate at northern mid-latitudes and in the Arctic.

Drew Shindell and Greg Faluvegi of NASA's Goddard Institute for Space Studies in New York quantified regional climate sensitivity to carbon dioxide, ozone, sulphate and black carbon, or soot, using a coupled ocean–atmosphere climate model.

Comparing their results to observed twentieth-century temperature trends, they calculated that greenhouse gases and ozone alone cannot explain rapid warming in the north. Declining levels of sulphates, which cool temperatures by reflecting sunlight, and rising levels of soot, which absorb solar radiation, probably account for as much as 45% of the observed Arctic warming over the past three decades, they say.