Global Warming

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 (IPCC), global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 20th century.

Most of the observed temperature increase since the middle of the 20th century has been caused by increasing concentrations of greenhouse gases, which result from human activity such as the burning of fossil fuel and deforestation.

Global dimming, a result of increasing concentrations of atmospheric aerosols that block sunlight from reaching the surface, has partially countered the effects of warming induced by greenhouse gases.

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Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice.

Other likely effects include changes in the frequency and intensity of extreme weather events, species extinctions, and changes in agricultural yields. Warming and related changes will vary from region to region around the globe, though the nature of these regional variations is uncertain.

As a result of contemporary increases in atmospheric carbon dioxide, the oceans have become more acidic; a result that is predicted to continue.

The rains have failed for four consecutive years and on 80 percent of Kenya’s land area, water resources are at a tenth of their normal levels. Corps are dying. The harvest is 28 percent of normal amounts. It is estimated, [World Development Report (WDR) 2010], that ten million Kenyans were going hungry because of the drought