The real consequences of global change only become apparent if the regional and local impacts are considered more closely. Global change research is, however, still subject to major uncertainties. This is even more true for regional climatic prediction because present-day climatic models still have limitations due to coarse resolution and internal errors and complex feedback mechanisms which play an important role.
Increasing concentrations of greenhouse gases in the atmosphere are likely to produce a substantially warmer climate on the earth. By absorbing some of the radiation emitted by the earth in the far infrared region of the spectrum, they can force the temperature of the earth to rise.
The concentration of some of the gases is increasing rapidly. If the present trend continues, a global warming by a few degree centigrade will be inevitable before the middle of this century.
Such a warming would have a profound effect on climate. Although temperature near the equator might change little, they would increase more than the average at high latitudes and near the poles. Higher evaporation rates would increase annual global rainfall by an estimated 7 to 11%.
The most extreme effects would be felt during the winter. Cold seasons would be shorter and warm seasons longer. In the higher northern latitudes, autumn and winter would be wetter and spring and summer drier. Rainfall would increase in the tropics but sub-tropical regions might become drier. Increased evaporation rates would lead to drier soils over wide areas.