Last March, scientists in the Canadian Forest Service issued a little-known report forecasting a risk of continental forest fires that today makes for some ominous reading.
Working with colleagues in Canadian provinces, the United States and Mexico, they compiled data showing that February was warmer than usual, including odd temperature readings across the Prairies, and that drought conditions were increasing in northern Alberta. The snow pack was well below average in Alberta forests, they wrote in their March 10, 2016 report, part of a recurring series called the North American Seasonal Fire Assessment and Outlook.
They predicted that El Niño, the naturally-occurring warming of the Pacific Ocean around the equator, would keep warm conditions in place, which would melt snow and cause vegetation to dry faster, providing fuel for fires. That would cause an “early start to fire activity in the boreal forests” by April, they wrote. Their map for northern Alberta projecting what conditions would be like by May was bright red.
On May 3, 2016, a terrifying wildfire swept through Fort McMurray, Alberta and into the history books. Two people died and many families were uprooted from their homes, in an evacuation of at least 88,000 people, the largest in Alberta history. At least $3.7 billion worth of property, more than twice the amount of the previous natural disaster on record, was destroyed. Canada lost around one per cent of its entire GDP in the second quarter that year.
Since then, forest service scientists have accelerated their work on a massive, two-year plan to map the probability of wildfires in most permanent settlements in the boreal forest of Canada, a 270-million hectare swath of hinterland that stretches across the country, storing carbon and regulating the planet’s climate.
“Fort McMurray really emphasized the importance of trying to put your finger on how likely it is that we’re going to get an event like that,” said Marc-André Parisien, a research scientist with the forest service, in an interview with National Observer.
“The urgency of trying to map fire probability got put to the forefront. We’re still trying to expand that program, but basically we’ve started doing most of that work less than a year ago.”
"They will burn down your town"
Parisien studies fire vegetation dynamics, and works closely with the forecasts written in part by his fire research scientist colleagues Kerry Anderson and Richard Carr.
He said he expected information on the mapping project to start “trickling in hopefully by next fall.” The value, he said, is that it will help communities think in terms of the space around them.
“These fires, they don’t ignite right next to town all the time. Sometimes, like the Fort McMurray fire, they ignite pretty far from town,” said Parisien.
“They pick up steam, they move fast, they’re very intense, and they will burn down your town. So when you start thinking spatially, about what you can do to limit incoming fires...you’re a step closer to protecting your community or mitigating potential problems.”
Last year’s wildfires were due to a record-breaking El Niño event, said Anderson, which affected Western Canada in particular. "Very early, warm weather, very mild winter, very warm, early spring, and very dry conditions, which set the stage for the explosive fire that occurred near Fort McMurray," he said.
The year 2016 was the hottest year on record, according to the World Meteorological Association (WMO)—a full 1.1 degrees Celsius above pre-industrial levels and 0.06 degrees above the previous record set two years ago.
El Niño also boosted warming in 2016, the WMO said, on top of greenhouse gas emissions, and contributed to sea level rise and shrinking of global sea ice.
Roughly four million hectares of land were affected by forest fires in Canada over the three years to 2016, well above the average over the past decade. The Intergovernmental Panel on Climate Change, which will meet in Montreal this September, has written about the increased risk of forest fires posed by climate change.
Natural Resources Canada says that the annual amount of forest area burned by wildland fires in the country's northwestern boreal regions rose steadily in the last half of the 20th century, and that some of this increase was attributed to climate change.
Changes in the climate affect how the forest scientists examine the spread of fires, said Parisien. “If you’ve got a changing climate, how’s that going to affect vegetation, how’s that going to affect fire? If fire changes, in turn, how is that going to affect vegetation? In some cases, if you have enough fire it can actually modify your climate.”
This year, warm ocean currents seem to indicate another El Niño in the summer, said Anderson, although much milder than last year. The conditions set in the spring, such as cold weather in Western Canada, have helped change the dynamics, he said.
“In terms of the general characteristics of the fire season that we’re facing, it’s best described as fairly average,” he said. “We may see some big fire events, but chances are that it’ll be business as usual.”
The science of predicting fires
Scientists say there are three ingredients necessary for large fires: an ignition, like a bolt of lightning or a discarded cigarette; the presence of flammable material, like plants and trees; and weather conducive to spreading fires, like heat and high winds.
Parisien’s work focuses on how likely it is that all three of those ingredients will occur at the same time, in the same place, he said.
“It’s a little bit like if you build your house on a floodplain. I can’t really tell you if there’s going to be a flood, but I can certainly tell you how likely a flood is going to be,” he said.
One challenge is that most of the Canadian population doesn’t live in the boreal forest, which extends from north of Quebec City across northern Quebec and Ontario, passing north of Thunder Bay and touching Winnipeg, before running northwest through Edmonton until it hits the Rockies.
But communities there tend to be isolated, said Parisien, sometimes accessible only by plane, or by a single highway in or out.
Readers looking for more information can check out the Canadian Wildland Fire Information System, which issues monthly and seasonal forecasts. It also contains information on the Canadian Forest Fire Danger Rating System.
With files from Mike De Souza