Temperatures in equatorial regions change little from January to July. Isotherms make a large north-south shift from January to July over continents in the midlatitude and subarctic zones. Highlands are colder than surrounding lowlands. Areas of perpetual ice and snow are intensely cold. The greatest ranges are in the subarctic and arctic zones of Asia and North America.
Annual range is moderately large on land in the tropical zone.
Annual range in coastal areas is less than the range inland at the same latitude. Small temperature ranges are found near oceans in the tropical zone. The greenhouse gases , carbon dioxide, methane, nitrous oxides, ozone and chloroflourocarbons, absorb longwave radiation and enhance the greenhouse effect. Carbon dioxide cycles through the earth system. It is taken up by vegetation and released by decomposition or burning.