"Growing evidence indicates that human activity is altering the climate in significant and potentially hazardous ways. The most recent assessment from the Intergovernmental Panel on Climate Change asserts that global temperature may rise by 2–5 °C (4–9 °F) during the next 100 years in response to rising greenhouse gas concentrations."
Reference: S. Solomon et al., eds., Climate Change 2007: The Physical Science Basis, Cambridge U. Press, New York (2007), (footnotes), online at Intergovernmental Panel on Climate Change
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