Greenhouse Gas: What Now, Mr. Gore?
Apr 24, 2008 8:55:24 GMT -5
Post by franko on Apr 24, 2008 8:55:24 GMT -5
OK, I'm more than a little snarly about the guy . . . but it seems that mankind is not the only emitter of greenhouse gases. What, you say, it is also a natural phenomenon?
The tiny mountain pine beetle has transformed British Columbia's vast pine forests into a major source of greenhouse gases, federal scientists say.
By the time the unprecedented infestation ends, the rice-sized beetles will have killed so many trees an extra billion tonnes of carbon dioxide will be wafting through the atmosphere, researchers from the Canadian Forest Service report in the journal Nature on Thursday.
That is five times the annual emissions from all the cars, trucks, trains and planes in Canada, says lead author Werner Kurz, who warns the beetle's impact goes far beyond the B.C. border.
Forests, along with oceans and grasslands, are critical sinks that soak up carbon dioxide from the atmosphere. Carbon dioxide is one of major heat-trapping gas linked to climate change.
"This piece of real estate is no longer contributing to the uptake," Mr. Kurz says of B.C.'s central interior forests. "To the contrary, it is currently a net source." This is because dead trees release carbon as they rot and burn.
Mr. Kurz and his colleagues at the Pacific Forestry Centre say B.C.'s beetle infestation is of "unprecedented scale and severity" and an order of magnitude larger and more severe than any other outbreak on record.
By the end of 2006, 130,000 square kilometers of forests had been attacked -- an area almost twice the size of New Brunswick. And by the time the infestation is over, the scientists estimate the pine beetle will have been responsible for the release of 990 million tonnes of carbon dioxide, or 270 million tonnes of carbon.
The figures include the amount of carbon the dead trees are no longer taking up as well as the carbon released as they decay.
Mr. Kurz predicts that within the next few years "the beetle will have eaten itself out of house and home" and the forest will begin to recover, at least in British Columbia.
The pine beetle is already moving on to greener pastures. It has crossed the Rockies into western Alberta's forests. This year's cold prairie winter should have helped set the bug back in Alberta, says Kurz.
But given favourable conditions in future, such as mild winters, the beetle could spread across Canada's vast northern boreal forest, one of the most important stores of carbon on the planet.
"I don't want to be alarmist, but it is certainly feasible that a future outbreak later this century could go across the boreal," Mr. Kurz said in an interview. "Basically the warmer the climate gets, the greater the chances that this could occur."
The study in Nature focuses on the B.C. outbreak that took hold in 1990s.
Several factors converged to set what Mr. Kurz describes as a "buffet" for the ravenous beetles.
Large fires had swept across the western provinces and states in the late 1800s and early 1900s, making way for vast pine forests. Smokey the Bear's "Only You Can Prevent Forest Fires" message and other fire prevention programs were so effective the forests grew without major disruption.
"Nearly a century of fire suppression efforts allowed the forest to reach a greater age, over a greater area," explains Mr. Kurz, adding that low logging rates also helped the pine forests to mature and flourish.
Then in the 1990s temperatures began to climb, putting an end to the severe winter cold snaps that used to keep the pine beetle in check. "Now you have a beetle that is able to go farther north and to higher elevation," says Mr. Kurz.
After the beetle bores under the bark and into the wood below, the trees' green needles turn red and eventually drop off, creating a serious fire hazard.
The outbreak has been a disaster for B.C. It is estimated more than 435 million cubic metres of timber has been lost. Many communities, fishing lodges and parks are now in the midst of dead forests that can stretch hundreds of kilometres.
Logging companies have been encouraged to salvage the dead wood before it rots. And there is growing interest in turning the trees into biofuel.
While the idea is controversial, Mr. Kurz says creating biofuel from the dead forests would mean less oil and gas would need to pumped out of the ground to fuel vehicles. "And you are creating a biofuel that is not competing with the human food supply," he says, referring to growing controversy over using corn, wheat, and other food crops to produce fuels for vehicles.
"Clearly we don't want to salvage every dead tree out there," says Mr. Kurz, noting that the trees do nourish the soil and provide wildlife habitat as they decay. "But I think as a society we need to have a dialogue about what to do with dead trees created by this insect outbreak."
link
The tiny mountain pine beetle has transformed British Columbia's vast pine forests into a major source of greenhouse gases, federal scientists say.
By the time the unprecedented infestation ends, the rice-sized beetles will have killed so many trees an extra billion tonnes of carbon dioxide will be wafting through the atmosphere, researchers from the Canadian Forest Service report in the journal Nature on Thursday.
That is five times the annual emissions from all the cars, trucks, trains and planes in Canada, says lead author Werner Kurz, who warns the beetle's impact goes far beyond the B.C. border.
Forests, along with oceans and grasslands, are critical sinks that soak up carbon dioxide from the atmosphere. Carbon dioxide is one of major heat-trapping gas linked to climate change.
"This piece of real estate is no longer contributing to the uptake," Mr. Kurz says of B.C.'s central interior forests. "To the contrary, it is currently a net source." This is because dead trees release carbon as they rot and burn.
Mr. Kurz and his colleagues at the Pacific Forestry Centre say B.C.'s beetle infestation is of "unprecedented scale and severity" and an order of magnitude larger and more severe than any other outbreak on record.
By the end of 2006, 130,000 square kilometers of forests had been attacked -- an area almost twice the size of New Brunswick. And by the time the infestation is over, the scientists estimate the pine beetle will have been responsible for the release of 990 million tonnes of carbon dioxide, or 270 million tonnes of carbon.
The figures include the amount of carbon the dead trees are no longer taking up as well as the carbon released as they decay.
Mr. Kurz predicts that within the next few years "the beetle will have eaten itself out of house and home" and the forest will begin to recover, at least in British Columbia.
The pine beetle is already moving on to greener pastures. It has crossed the Rockies into western Alberta's forests. This year's cold prairie winter should have helped set the bug back in Alberta, says Kurz.
But given favourable conditions in future, such as mild winters, the beetle could spread across Canada's vast northern boreal forest, one of the most important stores of carbon on the planet.
"I don't want to be alarmist, but it is certainly feasible that a future outbreak later this century could go across the boreal," Mr. Kurz said in an interview. "Basically the warmer the climate gets, the greater the chances that this could occur."
The study in Nature focuses on the B.C. outbreak that took hold in 1990s.
Several factors converged to set what Mr. Kurz describes as a "buffet" for the ravenous beetles.
Large fires had swept across the western provinces and states in the late 1800s and early 1900s, making way for vast pine forests. Smokey the Bear's "Only You Can Prevent Forest Fires" message and other fire prevention programs were so effective the forests grew without major disruption.
"Nearly a century of fire suppression efforts allowed the forest to reach a greater age, over a greater area," explains Mr. Kurz, adding that low logging rates also helped the pine forests to mature and flourish.
Then in the 1990s temperatures began to climb, putting an end to the severe winter cold snaps that used to keep the pine beetle in check. "Now you have a beetle that is able to go farther north and to higher elevation," says Mr. Kurz.
After the beetle bores under the bark and into the wood below, the trees' green needles turn red and eventually drop off, creating a serious fire hazard.
The outbreak has been a disaster for B.C. It is estimated more than 435 million cubic metres of timber has been lost. Many communities, fishing lodges and parks are now in the midst of dead forests that can stretch hundreds of kilometres.
Logging companies have been encouraged to salvage the dead wood before it rots. And there is growing interest in turning the trees into biofuel.
While the idea is controversial, Mr. Kurz says creating biofuel from the dead forests would mean less oil and gas would need to pumped out of the ground to fuel vehicles. "And you are creating a biofuel that is not competing with the human food supply," he says, referring to growing controversy over using corn, wheat, and other food crops to produce fuels for vehicles.
"Clearly we don't want to salvage every dead tree out there," says Mr. Kurz, noting that the trees do nourish the soil and provide wildlife habitat as they decay. "But I think as a society we need to have a dialogue about what to do with dead trees created by this insect outbreak."
link
