Wednesday, April 04, 2007

The mountain pine beetle and the greenhouse gas budget

This is what you might call a kind of climate feedback. The Toronto Star reports that the Canadian government will not include carbon exchange in forests in the calculations of the country's greenhouse gas (GHG) emissions.

Heavily forested countries like Canada could theoretically benefit by including the potential forest carbon sink (in part due to re-forestation practices) in their official GHG budget. More carbon sinks, fewer emissions reductions required. The inclusion of (net) carbon uptake in forests has been a huge issue at international organizations.

Why the about-face? The mountain pine beetle. Infestations of the beetle have devastated lodgepole pine forests across the west in recent years. The Canadian Forest Service blames warm weather - hot, dry summer and mild winters - and a large number of mature trees for an epidemic in central British Columbia. If that was not enough, all the leftover, dry, dead wood has increased the fire risk. The Canadian government now recognizes that forests may no longer provide the same carbon sink, and may actually "hurt" the overall GHG budget.

This is a very, very, very big change in policy. Canada has been arguing internationally for the right to include forests in GHG budgets since the inception of Kyoto. Now, the effect of warmer weather on those forests may change that basic position.

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