Research from an assistant professor at
Michigan Technological University just published has some somber implications for the future of climate change, particularly in Alaska.
Evan Kane, of Michigan Tech's School of Forest Resources and Environmental Sciences, co-authored a newly-published paper in the journal Nature Geoscience, and while the science may not be accessible to everyone, the message clearly is.
Every schoolchild learns the carbon cycle: the trees all over the planet use up carbon dioxide and give off oxygen; people do the opposite. Many forests in the world help maintain the carbon balance, among them the Alaskan forests.
However, Kane reports, with co-author Merritt Turetsky of the University of Guelph, Ontario, that in the past few decades, wildfires in Alaska have increased in severity and area, and the historically black spruce forests can't keep up with the carbon output anymore. As wildfires burn greater areas, and strip groundcover, the forests that grow back are not as effective at using up carbon as the black spruce has been.
"Since the proliferation of black spruce, Alaskan soils have acted as huge carbon sinks," says Kane. "But with more frequent and more extensive burning in recent decades, these forests now lose more carbon in any fire event than they have historically been able to take up between fires."
The researchers found that carbon output from forest fires in 2000 to 2009 was more than twice the carbon given off during each of the previous five decades.
The impact of this for climate change goes even beyond wildfires, though. Kane and Turetsky say the weaker forests that grow back, since they don't use carbon as efficiently and have less groundcover, also protect the Alaskan permafrost layer less. Permafrost loss is another concern for the carbon cycle, because warmer soil only encourages more wildfires, and also gives off more carbon in its turn as the permafrost thaws.
Writer: Sam EgglestonSource: Evan Kane, Michigan Technological University
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