2009-01-22

One degree warmer may not seem like a lot

The title of the post is a quote from the following article, which I found at the LA Times.

I've mentally poo-poohed some sort of global systems engineering approach to deal with warming, but the rate of the change seems to demand a faster short term solution than we can get any other way. If we can buy a few decades with an engineering solution and if we're not too near the precipice of catastrophic change, then we can probably legislate a more durable solution.



West's trees dying faster as temperatures rise
A study of old-growth forests predicts that if the trend continues, it could alter not just the region's woodlands, but the quality of wildlife habitat and forests' ability to store carbon.
By Bettina Boxall
January 23, 2009
More trees are dying in the West's forests as the region warms, a trend that could ultimately spell widespread change for mountain landscapes from the Sierra Nevada to the Rockies.

Scientists who examined decades of tree mortality data from research plots around the West found the death rate had risen as average temperatures in the region increased by more than 1 degree Fahrenheit.

"Tree death rates have more than doubled over the last few decades in old-growth forests across the Western United States," said U.S. Geological Survey scientist Phillip van Mantgem, coauthor of a paper published in today's issue of the journal Science and released Thursday.

The researchers found rising death rates across a wide variety of forest types, at different elevations, in trees of all sizes and among major species, including pine, fir and hemlock.

"Wherever we looked, mortality rates are increasing," said Nathan Stephenson, a study coauthor and USGS research ecologist.

Tree death rates had risen the most rapidly in the U.S. Pacific Northwest and southern British Columbia, Canada, doubling in 17 years. But the highest mortality -- more than 1.5% a year -- showed up in California.

If temperatures continue to rise, as many climate models predict, "it's very likely that mortality rates will continue to rise," Stephenson said.

That could eventually alter not just the face of Western woodlands, but the quality of wildlife habitat and forests' ability to store carbon. Extensive tree die-back could lead to wholesale landscape changes, converting forests in borderline areas to grass and shrublands.

see the rest at the LA Times.

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