Climate Feedback Loops
Via Ryan Avent’s Twitter feed and Paul Kedrosky, a nice look at what’s dooming the planet:
Forests in the Interior West could soon flip from carbon sink to carbon source, forest experts say. The region’s forests once absorbed and stored more carbon from the atmosphere than they released. But huge conflagrations — like the 138,000-acre Hayman Fire in Colorado in 2002 and the Yellowstone fires of 1988, which scorched 1.2 million acres — combined with a series of severe bark beetle infestations and disease outbreaks, have left large swaths of dead, decomposing trees in almost every major Western forest.
Those dead trees are releasing massive amounts of carbon dioxide, turning the region into a net emitter of carbon rather than a CO2 sponge.
The reversal, which has already occurred in Colorado and is anticipated in several other states, is the result of misguided forest management practices and a changing climate, forest experts say. Rising temperatures, resulting in shrinking snowpacks and drier conditions, have left the region’s forests more susceptible to disturbances, such as wildfires, bark beetles and disease.
A modest rise in world temperatures, if it stays modest, could be manageable. But a modest rise in world temperatures could lead to a big increase in greenhouse gas levels through a variety of feedback loops. Then the rise gets unmanageable, especially since once all this stuff gets into the atmosphere the climate just keeps getting hotter.