Changes

Secular scientists think that the Earth has experienced numerous [[Ice Age|ice age]]s over two million years, during which global temperatures dropped approximately 6 degrees Celsius 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.

Secular scientists think that the Earth has experienced numerous [[Ice Age|ice age]]s over two million years, during which global temperatures dropped approximately 6 degrees Celsius 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.

==Warming of other Planets==

==Global Warming on other Planets==

And it's not just the earth that has variations.  Since the Viking spacecraft reached Mars in the 1970's until recent readings were taken, the average temperature on Mars has risen 1.1 degrees Fahrenheit just as the average temperature on the earth has risen.  Since human industrialization is probably not to blame for the change on Mars, other causes are being considered.  The scenario most postulated by those who believe this is due to local changes on Mars and is not is dust storms<ref>http://www.space.com/scienceastronomy/070404_gw_mars.html</ref>, although solar conditions are certainly a possibility.  Recently, it has also been found that similar to the earth and Mars, that [[Neptune]] is undergoing global warming as well.  Measurements taken at the Lowell observatory in Arizona have shown an increase in Neptune's brightness and temperature since 1980 following the same pattern found on the earth, and Mars.  As with Mars, it is assumed this is not due to human influence. <ref>[[http://www.agu.org/pubs/crossref/2007.../2006GL028764.shtml]]</ref>

And it's not just the earth that has variations.  Since the Viking spacecraft reached Mars in the 1970's until recent readings were taken, the average temperature on Mars has risen 1.1 degrees Fahrenheit just as the average temperature on the earth has risen.  Since human industrialization is probably not to blame for the change on Mars, other causes are being considered.  The scenario most postulated by those who believe this is due to local changes on Mars and is not is dust storms<ref>http://www.space.com/scienceastronomy/070404_gw_mars.html</ref>, although solar conditions are certainly a possibility.  Recently, it has also been found that similar to the earth and Mars, that [[Neptune]] is undergoing global warming as well.  Measurements taken at the Lowell observatory in Arizona have shown an increase in Neptune's brightness and temperature since 1980 following the same pattern found on the earth, and Mars.  As with Mars, it is assumed this is not due to human influence. <ref>http://www.agu.org/pubs/crossref/2007.../2006GL028764.shtml</ref>

==Politics of global warming==

==Politics of global warming==