Changes

==Natural Variability of the Climate System==

==Natural Variability of the Climate System==

Evolutionary scientists who believe in global warming think that the Earth has experienced numerous [[Ice Age|ice age]]s over two million years, during which global temperatures dropped approximately {{temperature|6|11}} and then returned to normal. The frigid temperatures allowed ice sheets to expand southward, covering much of [[Asia]], [[Europe]], and [[North America]]. The cooling associated with ice ages is gradual, while the terminations are relatively rapid. However, even the rapid terminations of ice ages take centuries to millennia.{{cn}}

It is virtually universally accepted amongst climatologists that the earth has experienced numerous [[Ice Age|ice age]]s over two million years, during which global temperatures fluctuated created glacial and inter-glacial periods. The frigid temperatures allowed ice sheets to expand southward, covering much of [[Asia]], [[Europe]], and [[North America]]. The cooling associated with ice ages is gradual, while the terminations are relatively rapid. However, even the rapid terminations of ice ages take centuries to millennia.{{cn}}

==Natural Climate Change on Other Planets==

==Natural Climate Change on Other Planets==