Model calculations of competing climatic effects of SO₂ and CO₂ in fossil fuel combustion

Abstract

Fossil fuel combustion has two competing effects on the climate system, a warming due to the emission of CO₂ and other trace gases and a cooling due to sulphate particles formed from the SO₂ emission. A detailed parameterization of the relationship between fossil fuel burning and the SO₂ effect on backscattering and cloud albedo is implemented in a one-dimentional radiative convective model for assessing the climatic impact. The results show that at present the cooling induced by the combined effect of SO₂ completely counteracts the CO₂ greenhouse warming. The model predicts that by the year 2060 the SO₂- induced cooling reduces warming due to CO₂ by 66% in the IPCC scenario D. Attempts to slow-pace the fossil fuel burning will decrease the SO₂ concentration, which could further increase global warming.