ABSTRACT
Vegetation also has its own cooling effect in preventing the sun from baking the earth.
Carbon dioxide is the only variable over which man has any control, but since total carbon dioxide makes up less than half a per cent of the atmosphere, and the man-made portion is about 4 per cent of that, that control is puny. Without the discovery of fire we would certainly have less carbon dioxide in the atmosphere than we do today, but so what?
