clipped from blog.wired.com

Climate change turned the mountain pine beetle from an intermittent pest to relentless scourge, the villain behind a forest kill-off of historical proportions. And just to make this unfortunate cycle complete, the beetle will make climate change worse.

According to a study published today in Nature, damage wrought by the mountain pine beetle -- a tree-gobbling bug that, without winter deep-freezes to limit its numbers, has eradicated vast swaths of pine throughout throughout western North America  -- will turn those forests from net carbon sinks into carbon sources.

270 megatons of carbon will be added to the atmosphere between now and 2020 -- and that's just in British Columbia, which has experienced the worst outbreak, but is far from alone. The beetle's native range stretches from northern Mexico through northern British Columbia, and spans forests over most of the western United States.