Another Front in the Climate Wars

One of the subtle perversities of the climate problem is the potential effect of certain feedback loops--systems where warmer temperatures create conditions that produce still more warming. Such diabolical loops are not always counted in climate projections, and they produce a certain consternation when uncovered.

Nature magazine, in tomorrow's edition, will present a study of the Amazon rainforest, dating back to the 1980s, whose distressing conclusion is that a substantial decline in the health of the immense forest has seriously compromised its growth, reducing in turn its value as a carbon sink by as much as 50% over the past two decades. Causes for the decline are complex, but warmer temperatures and attendant reduction in rainfall are thought to be part of the problem. While protection of forests, especially tropical ones, not just in the Amazon region but in southern Asia and Equatorial Africa, has long been part of the climate change agenda, with today's report the profile of this problem in the discussions leading up to Paris may become more prominent.

Though the report is published behind a paywall, a summary can be found here, with fuller reports in The Guardian and Le Monde.