Changes

==Politics of global warming==

==Politics of global warming==

The global average surface temperature warmed about 0.5 °C (0.9 °F) over the second half of the 20th Century,{{Fact-science}} and to some the warming appears to be related to increases in carbon dioxide and other greenhouse gases. The possibility of adverse consequences has become a major concern for environmentalists.

The global average surface temperature warmed about 0.5 °C (0.9 °F) over the second half of the 20th Century, and to some the warming appears to be related to increases in carbon dioxide and other greenhouse gases. The possibility of adverse consequences has become a major concern for environmentalists.

Assessments of climate science by the United Nations (see [[IPCC]] - ''Intergovernmental Panel on Climate Change'')

Assessments of climate science by the United Nations (see [[IPCC]] - ''Intergovernmental Panel on Climate Change'')