Graphic: Projected warming (°C) due to greenhouse gases by the latter half of the twenty-first century in the absence of further increases in sulfate aerosol forcing. Based on years 61-80 of a transient CO2 increase experiment (+1% per year compounded) with a low-resolution GFDL coupled ocean-atmosphere model. [Source: Syukuro Manabe and Ronald Stouffer, Nature, 15 July 1993.]