Fossil fuel and biomass burning effect on climate - Heating or cooling?

Abstract Emission from burning of fossil fuels and biomass (associated with deforestation) generates a radiative forcing on the atmosphere and a possible climate chaw. Emitted trace gases heat the atmosphere through their greenhouse effect, while particulates formed from emitted SO2 cause cooling by increasing cloud albedos through alteration of droplet size distributions. This paper reviews the characteristics of the cooling effect and applies Twomey's theory to cheek whether the radiative balance favors heating or cooling for the cases of fossil fuel and biomass burning. It is also shown that although coal and oil emit 120 times as many CO2 molecules as SO2 molecules, each SO2 molecule is 50–1100 times more effective in cooling the atmosphere (through the effect of aerosol particles on cloud albedo) than a CO2 molecule is in heating it. Note that this ratio accounts for the large difference in the aerosol (3–10 days) and CO2 (7–100 years) lifetimes. It is concluded, that the cooling effect from coal and...