Any one of the relatively permanent factors that govern the general nature of the climate of a portion of the earth.
These factors include 1) solar radiation, especially as it varies with latitude; 2) distribution of land and water masses; 3) elevation and large-scale topography; and 4) the atmospheric concentration of greenhouse gases. The types of climatic controls were used as the basis for early climatic classifications. All of these have been nearly constant during historical time, but most or all of them have changed during geologic time and have caused large-scale changes of climate.
See climate control.
Source: American Meteorological Society