As more than 400 fires raged in forests across Canada on Wednesday, climate scientists say climate change worsens wildfires and vice versa.
Mohammad Reza Alizadeh, a climate data scientist affiliated with the Massachusetts Institute of Technology and McGill University, says there are three major ways in which climate change is influencing the wildfires ravaging Canada’s forests at record rates.
“Climate change has a direct and obvious effect of raising temperatures, which will dry out vegetation more quickly and more completely,” Alizadeh said in an interview Wednesday.
“The second part of the puzzle is the frequent lightning strikes that start fires. Recent studies show that climate change is significantly increasing the number of lightning strikes that are happening,” he said.
“And the third factor is the windy weather that fans the flames.”
He said vegetation in the eastern part of the country is less adapted to fires. Because precipitation is usually more frequent in the east at this time of year, the vegetation constantly draws moisture from the soil and the atmosphere. When there is drought or a heat wave, the vegetation gets very dry very quickly, and the fires are very intense and hard to fight.
About half of the approximately 400 fires happening in Canada now are out of control. Some 3.3 million hectares have already burned, which is almost 13 times more than the 10-year average of areas burned by wildfire in Canada.
“This is alarming for all of us. We need to take climate change as a serious factor for all those fires,” Alizadeh said.
“What is unique about what is happening now is that the fires are happening from coast to coast, from east to west, everywhere there are wildfires, with Quebec currently the most affected region,” Alizadeh said. “I am in Boston, and I can see the smog is affecting all the east coast moving from Montreal to New York to Boston and even Philadelphia with all those bad effects in terms of air quality.”
Daniel Kneeshaw is co-director of the Centre for Forest Research at UQAM and holds the research chair on Resilience and Vulnerability of Forests to Climate Change. He says these out-of-control forest fires are grabbing headlines now, but are only one example of the many negative, and possibly catastrophic, effects of climate change on forests.
“The effect of multiple disturbances … new insects moving in, fires, droughts, windthrows (trees uprooted by wind) … all these things are increasing at the same time. The scary part of the whole equation is that as we look to fight one battle and while we are focusing on something coming from our right, there are a whole lot of others coming from the left as well.
“Drought and fire will work hand in hand, and as you get fewer trees, you are pumping less water up into the atmosphere as well. So if we burn down all our forests, we will be putting less water into the atmosphere to fall back down as rain. So these kind of feedbacks could have potential repercussions in the long term. Drought leads to more fire which leads to more drought.”
Kneeshaw notes that none of this is surprising to those who study the climate, and he hopes it lends credibility to what climate scientists have been saying for decades. Wildfires are not just natural phenomena that can be seen as benign, and if policy-makers don’t act to reduce greenhouse gas emissions substantially, more wildfires are inevitable.
“The fire season will increase as climate change brings earlier springs. Fires will come along with that, starting earlier … more intense and lasting longer. So if you add a month or two to the fire season, you are going to increase the amount of burn. If you add on to that drought … multiple whammy. All these things are adding together to make the future look very hot and smoky.”
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