The devastation wrought by the tiny mountain pine beetle was hard to comprehend even before the report last week about its potential affect on climate change.
Thursday, May 01, 2008
During the unprecedented outbreak that started about eight years ago, the insect has destroyed pine forests in British Columbia covering an area twice the size of New Brunswick.
In a report published in Nature, federal scientists with the Pacific Forestry Centre in Victoria argue that the voracious pests are also leaving a huge carbon footprint.
The result of their appetite for pine is similar to a massive fire, leaving behind a forest that no longer stores carbon, but releases it to the atmosphere, dead trees that are no longer part of the solution but part of the problem.
The authors estimate that by 2020, by which time the beetles will have emptied their favourite buffet, the increased burden will be the equivalent of five years’ worth of all of the emissions from the transportation sector in Canada — all the cars, trucks, trains and planes.
That shocking prediction is based on modelling that looked at loss of the capacity of trees to absorb carbon as they would have if they had continued to grow.
The finding is bad news for anyone who was counting on B.C.’s forests as a painless way to counteract emissions from human sources as we look for ways to cut back.
But even before the mountain pine beetle attack began, our forests were a fickle ally. In many recent years, fires tipped the balances so that instead of being a net receiver, our woodlands were a source of greenhouse gases.
Now, whether because of climate change or just a random string of warmer years, the beetles have created a feedback loop that could make things worse. The lack of a hard winter set the stage for the beetles, which have in turn set the stage for more warm weather, if the scientists are right.
The new analysis of the effect of pine beetles could be interpreted to mean that our efforts to reduce emissions are being rendered meaningless.
More usefully, it should be considered another piece in a difficult puzzle, one in which natural disasters, whether insect infestation, forest fires or volcanic eruption, can play a large role but really run on separate tracks. We can’t expect to offset such large-scale events. All we can do is to adapt and, where possible, mitigate the damages.
We can make a difference in the impact of the beetle kill, as part of the actions we take that make sense for their own sake. Reforestation is clearly a key part. Young seedlings don’t immediately replace the benefit of mature trees, but over time they will grow more useful.
Earlier this month, Premier Gordon Campbell renewed a pledge to plant enough trees to offset the number being cut in the province each year.
That won’t be enough, however, to speed the return of the pine forests to carbon neutrality. The province should consider rapidly accelerating the tree-planting program rather than cruising along at the current pace.
And, rather than being left to rot, as much as possible of the beetle-killed wood should be harvested, either for lumber and pulp or for fuel.
None of this will completely counter the harm done by the mountain pine beetle. But mitigation is a worthwhile goal.
© The Vancouver Sun 2008