All living things need heat. Heat is a form of energy that is transferred from one body to another because of a difference in temperature. It is the cause of certain natural changes which occur in an endless cycle.
Tropical areas receive more heat from the sun than do polar regions.
The tropical atmosphere is hotter than the atmosphere in other areas. As a result the warm tropical air moves toward the poles. This starts a global movement, or circulation, of air. The global air movement has a great deal to do with what man does on Earth. Oceans too receive differing amounts of heat.