From Vancouver, where the hazy orange air smelled like a campfire last week, to smoke-clouded Saskatchewan, wildfires are adding even more scorch to a hot summer.
The fire season in Western Canada started early this year and with a vengeance. Lightning set off tinder-dry remote northern forests, augmented in the south by human stupidity ranging from dubiously tended campfires to criminal carelessness with discarded cigarette butts. Yes, still.
Experts say we’d better get used to this. Climate change is extending the wildfire season and increasing the intensity of the fires, adding risk to life, property and stretching provincial fire-fighting budgets.
In other words, we may have to get used to eating smoke more often.
You can’t point to any one big wildfire or bad season and finger climate change, any more than one bad storm can be blamed on climate-induced changes to weather patterns.
But based on recent trends, the outlook to the middle of this century is not good.
“Currently in Canada we average around 8,000 fires a year that burn about two million hectares, which is close to about half the size of Nova Scotia,” says Prof. Mike Flannigan of the University of Alberta’s department of renewable resources and one of Canada’s top experts on wildland fires.
“That’s like a 10-year running average. Back in the ‘70s it was about one million hectares, so we’ve doubled our area burned in the last 40-45 years.”
The increase has come in spite of advances in the way government agencies manage wildfires and an expansion of areas where they fight them aggressively, instead of letting them burn.
“But despite all those things the fire area burned has doubled,” Flannigan said in an interview. “I believe this is due to human-caused climate change.”
A discussion paper put together by B.C.’s Wildfire Management Branch as part of the province’s draft action plan to fight fires in an era of climate change offers a dire outlook if the planet continues warming.
It warns that by 2080 the size of the average B.C. wildfire will more than double to about 19,000 hectares, or 190-square kilometres. The fire season will grow by 30 per cent, along with intensity, and the province’s fire-free area will shrink by 39 per cent, the paper says.
Nationally, the wildfire season is expected to grow by about a month by the middle of this century and warmer temperatures will mean bigger, more intense fires if carbon emissions aren’t reduced.
Expect doubling or tripling of wildfire-burned area by mid-century
“For the mid-century to late century we can pretty much say that Canada-wide there will be a doubling or tripling of the area burned if emissions are kept at this rate,” Canadian Forest Service research scientist Martin Girardin, author of Natural Resources Canada’s web page on the issue, told Yahoo Canada News.
The insurance industry is already factoring wildfire growth into its forecasts, lumping it in with the expected increase in climate-induced extreme weather events.
“The new norm is on or around a billion dollars in these severe weather events,” said Steve Kee, the Insurance Bureau of Canada’s director of media and digital communications.
The bureau uses data compiled by Property Claims Services Canada to track large insurance claims but it notes many wildfire claims are below the radar because they don’t meet the agency’s $25-million threshold. The most recent large-scale claims have included B.C.’s Summer of Fire in 2003, which caused $240 million in insured losses and the 2011 fire that razed the town of Slave Lake, Alta., generating $770 million in claims.
There’s no smoking gun, if you’ll excuse the expression, when it comes to linking increased wildfire activity with climate change. But scientists like Flannigan and Martin infer a lot from the available evidence.
Three natural factors influence fire activity, said Flannigan: The availability, amount and dryness of fuel, a source of ignition such as lightning or a tossed cigarette and, perhaps most important, he says, the weather, especially air temperature.
“From our studies we found that in Canada, temperature’s really important in terms of area burned,” he said. “So the warmer it gets the more fire you have.”
The relationship of fire to temperature isn’t linear, said Flannigan. Warmer weather increases the likelihood of lightning activity and promotes moisture evaporation and retention. That leads to the drying of forests and ground waste that can’t necessarily be compensated by summer rain showers.
“Which means fuels will be drier and if you have drier fuels it’s easier for fires to start and spread,” he said.
A contributing factor is the climate-induced weakening of the jet stream, caused by greater warming that reduces the temperature difference between the equator and the poles. High-pressure ridges are likely to stay around longer.
“When that happens you get kind of a short-term drought and this is when fires like to hit,” said Flannigan.
Not everyone believes more serious fire seasons are inevitable, Flannigan concedes. Some see the string of recent bad fire seasons, such as B.C. in 2003, Slave Lake, and Quebec in 2013, when more than four million hectares burned, including one fire covering 650,000 ha.
“There’s an element of truth to that but there’s no doubt our planet is warming and as we warm those factors that I just gave you for temperature increases are playing a role,” Flannigan insisted.
Western Canada likely more prone to fire growth
Not every fire season will be bad, he said, but there will be more fire in the future.
Though no region is immune, Western Canada is likely going to suffer more from climate-related wildfire increases, said Flannigan, along with the North, where fires not threatening communities are often allowed to burn.
Northern fires also present an additional threat because northern boreal forests contain a lot of peat, millennia worth of tightly compacted partly decomposed vegetation. When a wildfire sweeps through the woods, it can set the peat alight and even after the surface fire is put out, the peat can smolder sometimes for a year or more.
Peat fires in Indonesia, lit as part of land-clearance programs, sent emissions to record levels in 2013 and are thought to have accounted for between 20 and 40 per cent of global fossil fuel emissions that year, said Flannigan.
“We have about 30 times more peat in the boreal forest than Indonesia,” he said. “If this becomes vulnerable due to climate change, then that can release significant greenhouse gases through the combustion process into the atmosphere, which will make it warmer, which feeds the fire.”
Expect the health risks from wildfire smoke to increase as well.
While it might smell like a campfire, wildfire smoke is a toxic soup that includes carbon dioxide, carbon monoxide, formaldehyde, nitrogen oxides, suspended ash particles and water vapour. While the gases can dissipate, the particulate matter can travel long distances.
Few studies have documented its health impact, according to a report by Quebec’s National Institute for Public Health. But studies of the impact of fine particulates found in urban smog show the connection with respiratory problems, the report said. There’ve also been suggestions that wood smoke increases cancer risk but the connection isn’t proven, the report said.
Public health officials regularly warn people with asthma and respiratory ailments to avoid strenuous activities or even going outside when wildfire smoke blankets a community. There’s no national data on the impact but Public Health Agency of Canada’s web site on wildfires notes emergency and doctor visits spike when the smoke rolls in.
Its long-term impact is under study, the agency says, including new evidence linking wildfire smoke to heart-related problems.
“As forest fires increase in length and intensity, their effects on human health will also increase,” the web page observes.
Few ways to reduce the overall fire threat
When it comes to mitigating the future wildfire threat there’s little that can be done on a large scale other than addressing the fundamental climate-change problem.
Some research is being done on ways to reduce a fire’s spread, such as mixing deciduous hardwood trees in with the more combustible conifers (spruce, pine and fir), said Martin.
“Vegetation types that are dominated by hardwoods, say aspen, are less prone to burning,” he said. “They do burn but they’re less risky.”
But work has been limited to computer simulations and studying past fires because a real-world field test on a specifically planted stand of timber would need decades, he said.
It’s also likely to meet resistance from forest companies, Flannigan suggested.
“It’s a solution around communities but at the landscape level, market will drive a lot of planting,” he said. “People won’t plant deciduous trees when the market wants timber and stuff for pulp. They want the conifers.”
There are steps people and local communities can take to reduce the risk, such as restricting development in fire-prone interface areas, where the forest meets the city. They can ensure highly flammable trees and shrubs aren’t sitting next to homes and other combustible material such as dead leaves are regularly removed. Homes, and especially roofs, can be built with more fire-resistant material for when burning embers drop from the sky.
The experts recommend participating in the FireSmart Canada program to learn how to reduce the risk.
The Insurance Bureau’s Steve Kee doubts there will ever come a day when insurance companies refuse coverage in some areas, the way the do for houses built on flood plains.
“Our industry, really the overall goal is to promote adaptation [to climate change] and safeguard Canadians about the impact of severe weather,” he said. “That’s the way you can control rising claim costs.
“I can’t foresee them refusing something like that but again insurers will price according to risk, and what you can do to lower those risks will help you in terms of your policy.”