12-9-12 Climate Dominoes


Earth Science Picture of the Day

September 3, 2012

Photographer: Bret Webster

What will happen when they are gone, these tall, too slender beauties, high fashion models slinking up the sides of the Rockies?

Bob McDonald, moderator of the CBC radio show, Quirks and Quarks, spoke with earth scientist Holly Maness on the December 1st broadcast. When the Lodgepole pines are gone, what then? Ms. Maness working at the University of Toronto studied what happened in British Columbia when 170,000 square kilometers of green forest became grey, leafless stands of dead trees. Her research, published in the journal Nature Geoscience, suggests mountain pine beetles have become so widespread they are not just benefitting from global climate change, but are contributing to it.

“The effects of climate change cascade,” she said. It is the domino theory writ large.

In the American West one needn’t drive far to see the truth of her observations. Colorado has been hard hit. In Montana I drive out of the river bottom and in less than twenty miles the brown death march begins up the mountain pass, a once beautiful forest, gone. When I first noticed the deaths, my neighbors blamed the beetle infestation on environmentalists like me.  The consensus was if those damned conservationists would let the loggers in, this would never have happened. Many still believe that, but a brave voice speaks up now and then.

Ms. Maness and other scientists have concluded the warming we are experiencing has allowed the spread of the tree-killing beetle into forests it was earlier frozen out of. The result is the summer temperature in beetle-ravaged forests is one degree Celsius higher than in healthy stands. Here is where the domino theory goes to work.

Trees soak up water from the ground. Then, they sweat it off, like humans, cooling themselves and the plants and animals around them. ”When you kill a tree, it’s going to stop sweating. That means the solar radiation that was previously spent evaporating water and cooling these trees is now going into heating the surface.” No forest, no cooling, warmer temperatures to promote the spread of the beetles – off we go.

Flying over miles of dead forest during her research proved vastly unnerving. Ms. Maness admitted she had no ready answers, but insisted a first step was to limit the use of fossil fuels. That would make Bill McKibben happy, but who listens to Bill McKibben?


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