Any human-induced changes in climate will occur against the background of natural climatic variations.Climate change reflects a change in the energy balance of the climate system, i.e.
The processes that cause such changes are called "forcing mechanisms".
Forcing mechanisms can be either "internal" or "external".
The classical time period is 30 years, as defined by the World Meteorological Organization.
The climate change referred to may be due to natural causes, e.g., changes in the sun's output, or due to human activities, e.g., changing the composition of the atmosphere.
He sees a torrent like the tail of a white horse streaming in the wind, such as it might be conceived would be that of the ' is mounted in the Apocalypse.
It is neither mist nor water, but something between both; its immense height (nine hundred feet) gives it a wave, a curve, a spreading here, a condensation there, wonderful and indescribable.
In 1956, an US based Chief consultant and oil geologist Marion King Hubert, (1956) predicted that if oil is consumed with high rate, US oil production may peak in 1970 and thereafter it will decline.
He also described that other countries may attain peak oil day within 20-30 years and many more may suffer with oil crises within 40 years, when oil wells are going to dry.
Internal forcing mechanisms are natural processes within the climate system itself, e.g., the meridional turnover.
External forcing mechanisms can be either natural (e.g., changes in solar output) or anthropogenic (e.g., increased emissions of greenhouse gases).