Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation. According to the 2007 Fourth Assessment Report by the Intergovernmental Panel on Climate Change.
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Wilsonbrad

Climate model projections summarized in the latest IPCC report indicate that the global surface temperature is likely to rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the 21st century.[2] The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions.
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Wilsonbrad

While the scientific consensus is that human activity contributes significantly to global warming[9][10][11][B], there is an ongoing political and public debate over whether the costs of mitigation outweigh the risks of inaction. The Kyoto Protocol is aimed at stabilizing greenhouse gas concentration to prevent a "dangerous anthropogenic interference".[12] As of November 2009, 187 states had signed and ratified the protocol.
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Wilsonbrad