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Computer models estimate that B.C. forests stored 328 million tonnes less carbon dioxide and released in excess of one billion tonnes of CO2 into the atmosphere during the outbreak, which began in 1999.

However, the effects of global warming — rising temperatures, higher rainfall, and an atmosphere richer in carbon dioxide — have created a “fertilization effect” which has accelerated the growth of trees, especially in the high-latitude forests that cover much of Canada, Russia and Europe.

Relatively cool temperatures in Canadian forests typically limit tree growth and carbon uptake to less than half the rate seen in tropical latitudes. But that is beginning to change.

New research suggests that climate change has increased the rate of growth and carbon storage in our forests, so much so that an additional one billion tonnes of carbon dioxide will be stored by our trees between the pine beetle outbreak and 2020.

“We have transitioned from a period at the peak of the mountain pine beetle outbreak, when the forests were a carbon source, to now, where they have become a sink (again),” said Kurz.

About half of all greenhouse gas emissions are absorbed by plants on land and in the ocean, but that hasn’t been enough to keep pace with the amount of CO2 being released by human sources.

“Climate changes naturally over the long term, but over the past 150 years we have seen a rise in the concentration of carbon dioxide and other greenhouse gases in the atmosphere that has been much more rapid than at any time in the past 600,000 years,” said Arora.