“The pine beetle infestation is the first major climate change crisis in Canada” notes Doug McArthur, a professor at Simon Fraser University in Vancouver. The pests are “projected to kill 80 per cent of merchantable and susceptible lodgepole pine” in parts of British Columbia within 10 years — and that’s why the harvest levels in the region have been “increased significantly.”
No surprise, then, that the disaster is even bigger in our most northern state, which just happens to be run by a global warming denier. As Senator Lisa Murkowski (R-AK) explained two years ago:
Warmer, drier air, has allowed the voracious spruce bark beetle to migrate north, moving through our forests in the south-central part of the state. At last count, over three million acres of forest land has been devastated by the beetle, providing dry fuel for outbreaks of enormous wild fires. To give you some perspective, that is almost the size of Connecticut.
The beetles are slamming other Western states, too. The largest infestation of mountain pine beetles in 20 years has hit more than a million acres of forest in northern Idaho and Montana, while 2.5 million acres in Washington face disease and insect problems.
Climate change is the culprit. Milder winters since 1994 have reduced the winter death rate of beetle larvae in Wyoming from 80 percent per year to under 10 percent.
And the carbon cycle feedback is huge, as quantified in the journal Nature, “Mountain pine beetle and forest carbon feedback to climate change,” (subs. req’d), while just looks at the current and future impact from the beetle’s warming-driven devastation in British Columbia:
The cumulative impact of the beetle outbreak in the affected region during 2000–2020 will be 270 megatonnes (Mt) carbon (or 36 g carbon m-2 yr-1 on average over 374,000 km2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source.
Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large-scale modelling analyses.
This catastrophic climate change impact and its carbon-cycle feedback were not foreseen even a decade ago — which suggests future climate impacts will bring other equally unpleasant surprises, especially as we continue on our path of no resistance.
– from climateprogress