Abstract

The buildup of radiatively active gases in the atmosphere has affected the energy balance of the climate system. The atmosphere is in balance between incoming solar radiation of about 250 watts/m2 and outgoing long wave infrared heat radiation of 250 watts/m2 from the cold atmosphere at 12 km. At the surface, the outgoing heat flux is about 350 watts/m2; the atmosphere radiates about 100 watts/m2 downwards to the surface. The surface also transfers heat to the atmosphere by convection and evaporation of water vapour. Thus, the atmosphere absorbs and reradiates about 100 watts/m2; this is called the greenhouse radiation. Any increase in the absorption caused by adding gases to the atmosphere will increase this greenhouse radiation. The man made increase in atmospheric greenhouse gases over the last 50 years has produced about a 2.5 watt/m2 increase in the greenhouse radiation(Dickinson and Cicerone,1986) and we expect a corresponding increase in surface temperature to occur.

© 1991 Optical Society of America