The average number of months where the average precipitation is greater than evapo-transpiration.

A name given to the occasional development of a warm ocean current along the coast of Peru as a temporary replacement of the cold Humboldt current which normally operates. El Nino is an extension of the Equatorial current and leads to an increase in surface water temperature of ten degrees and a decrease in plankton, which thrive in the colder current As a result of this reduction in their food supply the fish population is seriously depleted. It recurs every seven to fourteen years and results from a weakening of the SE Trades in the Pacific.

Increased gas (greenhouse) carbon dioxide, methane, and nitrous oxide, CFC.

Liquid water changes to invisible water vapour.

Evaporation from all terrestrial bodies.

This is a natural warming process of the earth where the earth’s atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun’s energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth’s surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth’s surface and atmosphere.

The interaction of the atmosphere, hydrosphere, lithosphere and biosphere.

This is a natural warming process of the earth where the earth's atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun's energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth's surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth's surface and atmosphere.

A belt of heat about ten degrees either side of the equator.