NEW ICE AGE PREDICTED -- BUT AVERTED BY GLOBAL WARMING?
November 17, 2008
Deep ice sheets would cover much of the Northern Hemisphere thousands of years from now -- if it weren't for us pesky humans, a new study says.
Emissions of greenhouse gases -- such as the carbon dioxide, or CO2, that comes from power plants and cars -- are heating the atmosphere to such an extent that the next ice age, predicted to be the deepest in millions of years, may be postponed indefinitely.
According to Professor Thomas Crowley of Edinburgh University:
- In about 10,000 to 100,000 years, Antarctic-like "permanent" ice sheets would shroud much of Canada, Europe and Asia.
- For the past three million years, Earth's climate has wobbled through dozens of ice ages, with thick ice sheets growing from the poles and then shrinking back again.
- These ice ages used to last roughly 41,000 years, but in the past half a million years, these big freezes each stretched to about a hundred thousand years long.
- Meanwhile, the temperature swings during and between these ice ages became more extreme, soaring to new highs and lows.
In some ways the ice age would be like those in the past few hundred thousand years, with a thick ice sheet covering North America, the study predicted. But in the model, Europe and Asia also succumbed to ice sheets up to 2 miles (3.5 kilometers) thick, stretching from England to Siberia -- something never before seen in models of past ice ages.
Source: Mason Inman, "New Ice Age Predicted -- But Averted by Global Warming?" National Geographic, November 12, 2008.
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