EFFECTS OF DOUBLING THE CO₂ CONCENTRATION ON THE CLIMATE OF A GENERAL CIRCULATION MODEL.

An attempt is made to estimate the temperature changes resulting from doubling the present CO//2 concentration by the use of a simplified three-dimensional general circulation model. Despite a number of simplifications, the results yield some indication of how the increase of CO//2 concentration may affect the distribution of temperature in the atmosphere. It is shown that the CO//2 increase raises the temperature of the model troposphere, whereas it lowers that of the model stratosphere. In particular, the increase of surface temperature in higher latitudes is magnified due to the recession of the snow boundary and the thermal stability of the lower troposphere which limits convective heating to the lowest layer. It is also shown that the doubling of carbon dioxide significantly increases the intensity of the hydrologic cycle of the model.