Solving the softwood lumber dispute with the U.S. may seem like child's play compared to saving lodgepole and limber pines -- the stalwarts of this $10-billion annual export industry -- from an emerging threat.

These trees are being killed at an alarming rate by British Columbia's mountain pine beetles. The forest area infested with the beetles has skyrocketed from 165,000 hectares in 1999 to 8.7 million hectares last year.

The infected area is a mixed stand, but lodgepole pine is the predominant species. In total, there are 15 million hectares of lodgepole pine.

A major cause of the beetle boom is climate change, says Allan Carroll, a research scientist with Natural Resources Canada's Pacific Forestry Centre in Victoria, B.C. With warmer temperatures, the insect is not being killed by winter cold in the B.C. Interior at the rate it once was, and the heat accumulation in warmer summers is allowing a generation to emerge in a single year. This makes them far more prolific than with a two-year cycle.

Other factors leading to the mountain pine beetles' expansion are successful suppression of forest fires, and the forestry industry allowing more lodgepole pines to mature, which makes them more suitable as hosts for the insect.

The beetles emerge from the tree where they hatched, select another tree to attack, mate, the eggs hatch in late summer, the larvae feed on the tree and that activity, along with fungus that results, kills the tree.

The only way to control it directly, Carroll says, is to cut down the trees the beetles are infecting; they will die when the lumber is processed in a mill. But the lumber industry would have to cut 100,000 hectares of trees a year just to keep the infected area the same size. That is beyond its capacity.

Dead trees can be harvested for lumber if they can be milled before they rot. In wetter regions, which encompass 60 to 70 per cent of the forests, it takes three to five years for a tree to rot. In drier areas, it's 15 to 20 years.

Carroll says by 2002, a large number of beetles were established on the northeast slopes of the Rockies in the Peace River area and toward Jasper. Now there's a substantial population.

The mountain pine beetle has always been able to multiply in southern parts of B.C. and into the U.S. But with a warmer climate enabling the beetles to survive farther north, they now can potentially spread eastward into Jack pine forests across the Prairies, Northern Ontario, Quebec and into New Brunswick.

The colour of trees goes from green when healthy to yellow and orange when infected, to red (dead) and grey (rotting).

The looming destruction of much of Canada's forest resource appears likely to rob Canadian governments, companies and individuals of wealth and livelihood. As with other consequences of global warming, the pine beetle threat is gradual, insidious and devastating.