Tuesday, July 14, 2009

Global warming's timing problem

Beth Daley in the Boston Globe – and don’t miss the denialist spluttering in the original site’s comments section: Evidence is growing that climate change is exacerbating water scarcity problems around the world. But now, a study shows that parts of even drenched New England may be facing water shortages as the world warms and demand increases.

New U.S. Geological Survey research shows that increased demand for water and a warmer climate will likely decrease the amount of water available in the streams and aquifers of southeast New Hampshire’s Seacoast region. Similar worries are on the minds of Massachusetts and other New England water scientists.

USGS hydrologist Thomas Mack estimates that summer stream flows, which helps feed groundwater aquifers, in the Seacoast region could be ten percent less by 2025 than they are today. Meanwhile, warmer temperatures could increase evaporation and lengthen the growing season where water is sucked up by plants.

A lot of the problem has to do with timing. About half of the water that recharges the region’s aquifer is from spring snowmelt, said Mack, allowing it to be plentiful to residents for summer lawn watering and other uses. But global warming is causing the snow to melt earlier by around two to four weeks. At the same time, more rain, instead of snow, is expected to fall in the winter. That means the aquifer is filling up earlier in the spring….

Mount Madison in the White Mountains of New Hampshire, shot by Petersent, Wikimedia Commons

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