Data graphs show variations in temperatures measured from thermometers over the past 140 years; and thermometers, tree rings, corals, ice cores and historical data over the last millennium. Both graphs show a rise in temperatures over the past 140 years.

Variations of the Earth’s surface temperature over the last 140 years and the last millenium. [From the Intergovernmental Panel on Climate Change (IPCC) report, Climate Change 2001: The Scientific Basis.]

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