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Climate change threshold nears for rapid increase in wildfires in Canada

Posted on 26 December 2011 by John Hartz

Note: This is an original article by Takver posted on the San Francisco Bay Area Independent Media Center on Dec 17, 2011. Unless otherwise stated by the author, all content is free for non-commercial reuse, reprint, and rebroadcast, on the net and elsewhere. Opinions are those of the contributors and are not necessarily endorsed by the SF Bay Area IMC.

The climate is changing in Canada. New research indicates that large areas of Canada are approaching a threshold value where they may experience a rapid increase in the size of wildfires. Both the area burnt down annually and the average size of the fires would increase, write the researchers of the Helmholtz Centre for Environmental Research (UFZ) and the University of Michigan who undertook the research.
Animated graphic of Seasonal Forest Severity Rating
Wildfire is expected to increase as a result of climate change in Canada with the majority of wildfires occurring in non-fragmented coniferous forests. Recovery from fire usually takes 20 years. If fires or logging occurrs on a frequent basis, this can cause landscape traps in which the ecology becomes permanently changed. (See example: mountain ash forest landscape trap of Victoria, Australia)

"Changes in the wildfire regime have a significant impact on a local and global scale and therefore on the climate as well. It is therefore important to understand how the mechanisms which shape these wildfires work in order to be able to make predictions on what will change in future," explained PD Dr. Volker Grimm of the UFZ in a media release.

The scientists evaluated data on fires greater than 200 hectares from the Canadian Forest Service from 1959 to 1999. The data showed that three ecozones in Canada are close to a turning point: the Hudson Plains south of the Hudson Bay, the Boreale Plains in the Mid-West, and the Boreale Shield which stretches from the Mid-West to the East coast and is therefore the largest ecozone in Canada. The Boreale Shield is the closest to the turning point.

Looking at the data for the Boreale Shield more closely, the researchers found that around 1980 the average size of the fires in this part of the provinces of Alberta, Saskatchewan and Manitoba tripled rapidly.

"In our opinion this is a sign that there are also threshold values for forests above which the wildfire regime drastically changes," reports Volker Grimm. "It is likely that the Boreale Plains have in recent decades, particularly around 1980, experienced a change to a system characterised by wildfires. This has fundamental repercussions for the environment and the combating of wildfires. Small changes in the fire propagation parameters have a great impact on the size of the fires."

The gradual changes that accompany climate change can result in an abrupt and sharp increase in the size of the fires, argue the researchers.

From the abstract for the paper - Understanding Shifts in Wildfire Regimes as Emergent Threshold Phenomena by Richard D. Zinck, Mercedes Pascual, and Volker Grimm published in The American Naturalist DOI: 10.1086/662675.

Transitions across this critical threshold imply abrupt and pronounced increases in average fire size. The model predicts that large regions in Canada are currently close to this transition and might be driven beyond the threshold in the future. We illustrate this point by analyzing the time series for large fires (>199 ha) from the Canadian Boreal Plains, found to have shifted from a subcritical regime to a critical regime in the recent past. By contrast to its predecessor, the model also suggests that a critical transition, and not self-organized criticality, underlies forest fire dynamics, with implications for other ecological systems exhibiting power-law-like patterns, in particular for their sensitivity to environmental change and control efforts.

The researchers are also investigating parallels with disease propagation: whether fuel reduction strategies can work in a similar way to vaccinations against the spread of disease.

Wildfires contributing to permafrost thaw, methane release

Another threat to the climate is posed by increasing wildfires leading to more rapid thaw of the permafrost, releasing methane, a greenhouse gas 20 times more powerful than cabon dioxide. "I maintain that the fastest way you’re going to lose permafrost and release permafrost carbon to the atmosphere is increasing fire frequency," said Michelle C. Mack, a University of Florida scientist who is studying the Alaskan Anaktuvuk fire that ocurred in 2007. "It’s a rapid and catastrophic way you could completely change everything." reported the New York Times in As Permafrost Thaws, Scientists Study the Risks. Read her concluding statement in her research letter published in Nature 28 July 2011 - Carbon loss from an unprecedented Arctic tundra wildfire (PDF).

Our observations of Carbon loss from the Anaktuvuk River fire support the idea that tundra fires have the potential to release large amounts of Carbon and decrease landscape Carbon stocks, having an immediate impact on atmospheric Carbon and climate that is rapid in comparison to other potential climate change feedbacks from tundra ecosystems. Although the future trajectory of ecosystem recovery in the Anaktuvuk River fire scar is yet unknown, most of the plausible short- and long-term scenarios lead to amplification of climate warming.

A similar dramatic increase in wildfires due to climate change threatens the forests of Yellowstone National Park. Climate change will also cause an increase in extreme fire-weather in Australia.

Canada withdraws from Kyoto Protocol

The Canadian environment minister Peter Kent announced Canada's withdrawal from the Kyoto protocol on December 12 in a statement from the House of Commons. Canadian carbon emissions are up 35% since 1990, despite a target under the protocol of 6% lower than 1990 levels by 2012, according to an AFP report.


  • Understanding Shifts in Wildfire Regimes as Emergent Threshold Phenomena (abstract) by Richard D. Zinck, Mercedes Pascual, and Volker Grimm published in The American Naturalist DOI: 10.1086/662675.
  • Factors influencing national scale wildfire susceptibility in Canada, 20 November 2011 (abstract) doi:10.1016/j.foreco.2011.10.031

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Comments 1 to 5:

  1. From My Comment: note: the link in "(See example: mountain ash forest landscape trap of Victoria, Australia)" doesn't work After months of reading your posts I finally gave in and made an account as this is something I can comment about directly. In the 2090-2099 map, the dark red area in the south of AB, SK, and MB is mostly prairie (farmland) with the occasional patch of deciduous trees, mostly poplar. The exceptions may be around the bottom of Lake Winnepeg (the big lake that drains into Hudson's Bay), the northern most tip of red in AB and the south west tip that moves from AB into BC. I live right in the middle of SK, on the edge of the prairie grasslands and boreal forest. What has been going on here is we had 1 summer when it rained every day, then 3 summers with almost no rain. Since then it's been alternating normal rain patterns with raining every day, leaning to more rain than usual. The winters have been leaning more and more to drought with 1999 being the first brown winter solstice in SK since, probably, before the ice ages started. Today, there's 0-2 inches of snow around town - not quite a brown solstice, but lots of grass showing. All this has put a stress on the trees - in this area the trees are about half jack pine with the rest being white and black spruce, a smattering of tamarak (larch), and some areas of poplar. The jack pine have become increasing vulnerable to dwarf mistletoe, a parasitic infection that causes some cancerous looking growth called witch's broom, that kills the trees within 5ish years. So we've got these forests of, mostly, dead and dieing jack pine and the provincial government started hiring people to go clearcut the diseased trees. But, what good are they? So the contractors cut out most of the diseased trees and all the healthy ones. What was left behind was acres of dead branches. Fuel for the (coming) fire. Because of the unseasonably warm winters the country is experiencing, the pine bark beetle has found the forests of BC (pretty well the whole province) to be a nice place to live now. They've made it over the mountains on the warm pacific winds (chinooks) and are moving down the Athabasca River where they'll eventually end up in nw SK. And they're leaving behind 100s of sq miles of dead trees. Of course the BC timber industry, in an attempt to beat the beetles to the trees, is ramping up clear cutting of forests. No doubt they're leaving behind lots of nice dry branches as is the practice here. And then, we also have the Tar Sands in the ne dark orange area of AB (about 25% of the province) where they're clear cutting and leaving, not dead branches this time but, all that nice flammable bitumen exposed. So yes, I think forest fires might wipe out the Canadian Boreal Forest quite nicely in the coming years. I saw an article somewhere (sorry no link) hypothesizing that northern forests (especially coniferous) actually contribute to warming, so it may end up a net cooling effect taking into account the lessened albido, the co2 from the fires, and the blocking effect from the ash in the sky. BUT I am going to miss them and the deer are going to miss them and the bears are going to wander into towns and get shot. What a sad day that I hope I won't be here to see.

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    Moderator Response: [JH] Link fixed. Thank you for sharing your personal observations and trepidations.
  2. Thanks for reposting this article. The first two links now work, but the rest need fixing, including all the source links at the bottom.
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    Moderator Response: [JH] I will proceed to fix the other links. Thanks for bringing these glitches to our attention.
  3. @takver: All links have been fixed. I keep forgetting that the SkS system automatically changes all of the embedded links in articles when they are imported for reposting. My apologies to everyone for the inconvenience.
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  4. @takver: Kudos on your well-written and well-researched article.
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  5. Adding to Ariadne's post, it appears the factors in the study underestimate the predation and disease elements. In Ontario, blights are spreading and attempts to deal with the ash-bore infestation have failed. It's not the bump in heat that's pushing the forest-fire spread - it's about the forests turning into fuel dumps.
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