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Climate Change
The term ‘climate change’ refers to changes in modern climate, including the rise in average surface temperature known as global warming. There is growing scientific consensus that Greenhouse Gases (GHGs) arising from human activity are a major cause of climate change.
GHGs make up only about 1 per cent of the atmosphere, but they act like a blanket around the earth, or like the glass roof of a greenhouse - they trap heat and keep the planet some 30 degrees C warmer than it would be otherwise.
Human activities are making the blanket thicker - the natural levels of these gases are being supplemented by emissions of carbon dioxide from the burning of coal, oil, and natural gas; by additional methane and nitrous oxide produced by farming activities and changes in land use; and by several long-lived industrial gases such as Hydroflorocarbons that do not occur naturally.
These changes are happening at unprecedented speed. If emissions continue to grow at current rates, it is almost certain that atmospheric levels of carbon dioxide will double from pre-industrial levels during the 21st century. A rise in temperature will be accompanied by changes in climate - in such things as cloud cover, precipitation, wind patterns, and the duration of seasons.
The Stern Report, commissioned by the UK government, assessed the economic impact of climate change and concluded that the cost of mitigating climate change was lower than the potential economic cost of climate change itself. The report found that the cost of mitigating
climate change could be limited to around 1% of global GDP annually,
compared to the equivalent cost of losing at least 5% of global GDP each
year. When a wider range of risks and impacts were considered, the potential
loss could be as much as 20% of global annual GDP. Therefore prompt and
strong action is needed.
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