Emphasizing the ideas voiced in Part Duh that the notion of subsidizing "avoided deforestation" was a stupid idea. Beetle Mania.

natural events can upset a forest’s carbon calculus. Big fires, for instance, spew plenty of CO2 into the atmosphere, and the dead trees that remain eventually decompose by microbial action, releasing more of the gas.

By killing trees by the thousands, widespread insect infestations can do the same thing. But rarely have insect blights been considered when determining a forest’s carbon balance.

Now Werner A. Kurz of Natural Resources Canada and colleagues have calculated the impact of an infestation of mountain pine beetles on pine forests in British Columbia. The effect, they report in Nature, is startling: the forests are now a large carbon source, and will remain so at least until 2020, long after the infestation peaks.

At more than 32 million acres and counting, the pine beetle blight is at least an order of magnitude larger than any previous recorded infestation by the insect. And global climate change, Dr. Kurz said, is partly responsible: winter temperatures no longer get low enough to kill off the beetle, and warmer summers allow greater reproductive success.

I've been writing about this for years. It isn't just the higher minimum winter temperatures that have allowed the beetles to prosper, it is also summer drought and fire suppression.

The beetles attack weak stands of trees. In the past this benefited the forest. Weak trees died, then burned, making room for new growth. The result was a vibrant mixed-age forest more resilient than a monoculture of same aged trees.

Suppressing fire - something that has been going on for many decades - reduced stress on the beetles, allowing them to better thrive, and setting the stage for spectacular burns when the standing dead finally did catch since there was more fuel.

The combination of changes means that there will be less pine forest in the area. The carbon sequestered by trees is being released. We should expect that every forest will have future impacts and we should focus on sensible forest management, even when that means clearing areas and letting natural fires take their natural course, rather than trumped up climate wheezes.

BTW, there have been some efforts to make the most of the beetle infestation. There is a fungus that infects trees attacked by beetles. Its growth stains the pine wood a blue color. Lumber made from such trees is called "denim pine" and is sold as a specialty product. The wood is just fine, as strong as wood from fungus free trees. When such wood is used for home building the carbon in it is in effect sequestered more durably than leaving it to burn or rot in the forest.