Changes

Politicians who support the [[Kyoto Protocol]] have made the claim that there is a cause and effect relationship between increases in atmospheric concentrations of [[greenhouse gas]]es and air temperature.

Politicians who support the [[Kyoto Protocol]] have made the claim that there is a cause and effect relationship between increases in atmospheric concentrations of [[greenhouse gas]]es and air temperature.

Hansen's group at the Goddard Institute wrote, "Global warming is now 0.6°C in the past three decades and 0.8°C in the past century." <ref>http://data.giss.nasa.gov/gistemp/2005/</ref>

Hansen's group at the Goddard Institute wrote, "Global warming is now 0.6°C [1.08°F] in the past three decades and 0.8°C [1.44°F]in the past century." <ref>http://data.giss.nasa.gov/gistemp/2005/</ref>

==Natural variability of the climate system==

==Natural variability of the climate system==