Climate variability and change: Difference between revisions

Revision as of 00:10, 23 December 2005

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[[Image:Vostok-ice-core-petit.png|thumb|right|Variations in CO2, temperature and dust from the [[Vostok]] ice core over the last 400 000 years]]

The term '''climate change''' is used to referrefers to changes in the [[Earth]]'s global [[climate]] or regional climates. It describes changes in the variability or average state of the atmosphere - or average weather - over any time scale from decades to millions of years. These changes can come from internal processes, be driven by external forces or, most recently, be caused by [[anthropogenic climate change|human]] activities.

In recent usage, especially in the context of [[natural environment|environment]]al policy, the term "climate change" is often used to refer only to the ongoing changes in modern climate, including the average rise in surface [[temperature]] known as [[global warming]]. In some cases, the term is also used with a presumption of human causation, including in the [[United Nations]] [[UNFCCC|Framework Convention on Climate Change]]. The UNFCCC uses "climate variability" for non-human caused variations[http://www.grida.no/climate/ipcc_tar/wg1/518.htm].