Global warming is a slow increase in the overall temperature of the earth's atmosphere generally created by the greenhouse effect. This effect is caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.
I don't know if we are talking about the same war but the immediate consequence for Africa of the declaration of war in Europe was the invasion by the Allies of Germany's colonies. Neither side had prepared for war in sub-Saharan Africa. Indeed there was short-lived hope that it might be isolated from the war.