After the deadly inferno in Lytton, B.C., experts are looking ahead at the blazes that climate change will likely make worse and more frequent – and the devastating impact smoke will have on Canadians’ health
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Main Street in Lytton, B.C., lies in ruins on July 9, days after
record-setting temperatures fuelled a wildfire that largely
destroyed the Fraser Canyon village. Photography by Jackie Dives/The Globe and Mail
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But as officials and residents absorb the shock of this tragic turn of events, a larger issue looms. The heat wave that gripped the Pacific Northwest last month and set the stage for an outbreak of wildfires was extraordinary relative to the region’s past. It may also be the harbinger of the new normal in a climate change-driven future.
Wildfire experts, climatologists and doctors warn that as the climate warms, Canada is headed for record-smashing high temperatures, longer and increasingly intense wildfire seasons, and prolonged periods of smoke exposure. Just last week, international researchers released analysis that suggests climate change made the heat wave 150 times more likely than it otherwise would have been. The future of fire in Canada is, in a word, more.
While the fire that razed Lytton and killed two residents is believed to have been ignited by human activity, it was the hot, dry, windy weather and tinder-like vegetation that allowed it to rage with such abandon. To many, climate change has been seen as a slow-moving phenomenon with consequences for other people, somewhere else. But then, a Canadian town hit temperatures halfway to the boiling point and burned to the ground.
In an interview with The Globe and Mail last week, Prime Minister Justin Trudeau said the wildfires and deadly June heat wave that set more than 1,200 new temperature records across North America have provided the Liberal government with an opportunity to bolster its climate-change agenda. “We simply have to be even more aggressive in our thoughts,” he said.
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Active wildfires in British Columbia As of July 14, 2021 
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Murat Yükselir / The Globe And Mail, Source: Canadian Wildland Fire Information System |
The area burned by wildfires in Canada has doubled since the early 1970s, said Mike Flannigan, research chair for predictive services, emergency management and fire science at Thompson Rivers University, in Kamloops. In California, where almost 10,000 wildfires raged during last year’s record season, that trend is even more pronounced. The area burned has increased by at least a factor of five.
Dr. Flannigan said it’s going to get worse – it’s just a matter of how much worse. Modest predictive modelling suggests the area burned in Canada will double again by the end of the century; more aggressive modelling predicts it will increase by a factor of as much as 11.
While raging fires illustrate the implications of climate change with dramatic visual impact, the flames themselves don’t tend to claim lives in Canada. It’s the heat that precedes and sustains them, and the smoke they billow far and wide, that can have widespread and devastating implications for human health. Even people who live far from the actual wildfires can be exposed to poor air quality from burning biomass. In 2018, smoke from wildfires in British Columbia spread across Canada and as far as Ireland; last year, smoke floated from the states of Washington and Oregon into Western Canada.
Wildfires are about extremes. In Canada, 3 per cent of fires on average burn 97 per cent of the total area burned. In the Western U.S., just 1 per cent of fires is responsible for destroying 99 per cent of the total land razed. “That’s the nature of the beast,” Dr. Flannigan said. “It’s part of our ecosystem. It’s Mother Nature at work, cycle of life. We can’t eradicate it, nor should we.”
So, how do we live with wildfires, especially when there’s bound to be more of them?
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Investigators suspect human activity may have initially sparked the
Lytton fire, but hot, dry and windy weather – the result of a 'heat
dome' that enveloped B.C. and the U.S. Pacific Northwest – are what
made it spread so quickly and to such destructive effect.
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Scientists are still debating whether climate change is exacerbating the situation in ways beyond temperature, such as increasing the likelihood of the blocking pattern that held the hot, high-pressure air system over the West during the recent heat wave. Dr. Flannigan said research in North America suggests that while this blocking pattern isn’t necessarily happening more frequently, it is increasing in intensity and duration. Another factor in the role of climate change is precipitation, which is harder to determine because of high variability of rainfall in the West.
But whatever climate effects are lurking in the background, once a wildfire has started, its potential impact over a broad swath of the country in the form of smoke can be predicted with growing confidence. This is the goal of BlueSky Canada, a smoke-forecasting project led by atmospheric scientists at the University of British Columbia.
On a daily basis, the BlueSky system takes in infrared satellite data that can spot where fires are burning, and combines them with data on fuels, soil moisture and wind patterns at altitude to estimate how much smoke is likely to be injected into the air and where that smoke is likely to find its way back to the surface.
Not every breath of smoke is created equal, because not all wildfire smoke is created equal. In addition to gases such as carbon dioxide, nitrogen oxides and volatile organic compounds, it’s also full of particulate matter – solid particles and liquid droplets of varying sizes. When it comes to smoke exposure, air quality indexes and studies tend to look at what’s known as PM2.5, which is a composition of fine particles with diameters less than 2.5 microns. That’s about 30 times smaller than the diameter of a human hair. The composition of the PM2.5 depends entirely on what, exactly, is in the line of fire. Grasses, trees, houses and cars, for instance, all release different substances into the air when burned.
“These particles are important because when you breathe them in, they’re small enough to get into your cardiovascular system,” said Chris Rodell, a BlueSky Canada researcher.
About a decade ago, the Canadian Council of Ministers of the Environment developed a Canadian Ambient Air Quality Annual Standard for PM2.5; the standard is currently met when annual levels of PM2.5 are 8.8 micrograms per cubic metre or less. In B.C., where air quality is generally very good, the 24-hour average of PM2.5 detected in the air would typically be lower than 10 micrograms per cubic metre, said Sarah Henderson, scientific director in environmental health services at the B.C. Centre for Disease Control. On the smokiest days in the province, the PM2.5 value could hit 300 or more.
With concentrations that high, visibility is greatly reduced and, as Dr. Henderson puts it, “You can smell the smoke and taste it.” But it’s at levels of just 30 micrograms or so per cubic metre that the population starts to respond adversely to the smoke. “When it looks really bad, people think it is really bad,” she said. “But it becomes unhealthy long before it looks terrible.”
PM2.5 can reach deep into the lungs, prompting the body to mount an immunological response just as it would if it detected the presence of an unwanted bacteria or virus. “The immunological response ends up causing inflammation, and that inflammation is systemic,” says Dr. Henderson, who has been studying wildfire smoke for two decades and has published upward of 40 papers on the topic. In other words, particulate pollution from smoke can affect every organ system in the body.
So while people with asthma and chronic obstructive pulmonary disease are the canaries in the coal mine of wildfire smoke, the inflammation can also increase the likelihood of a cardiovascular event such as a heart attack or a stroke. Emerging research also suggests that the body’s response to smoke exposure can make it harder for people with diabetes to balance their insulin levels, and may affect brain function for those whose cognitive abilities are already compromised.
Dr. Henderson is so concerned about the health effects of smoke exposure that she helped develop a supplement to the classic Air Quality Health Index, which was originally developed for urban environments where the air pollution mixture is dominated by traffic-related and industrial pollution. The calculation includes PM2.5, but particulate matter is afforded relatively little weight. Practically speaking, this meant the classic index tended to underreport the health risk during fire season. The supplement to the classic index, known as AQHI-Plus, only looks at PM2.5 levels, better reflecting the air quality experienced during forest fire season. The AQHI-Plus is now in use in B.C., and Dr. Henderson said its use is also under consideration in other provinces and territories.
Also important when considering the effects of wildfire smoke is the duration of exposure. Smoke can be transient, lasting hours or days, or it can be persistent. Atmospheric conditions can park smoke over a particular area for weeks or even months, as was the case in Yellowknife in 2014. The “summer of smoke” in the Northwest Territories capital was one of the longest and most severe wildfire smoke exposures logged in the global evidence base.
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SNAPSHOTS IN SMOKE Three Canadian smoke forecasts made over a two-week period illustrate the profound effect of the recent heat wave that peaked in British Columbia around June 28 
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Murat Yükselir / The Globe And Mail, Source: Firesmoke Canada |
Nearly 400 wildfires burned that year, enveloping the city of 20,000 in smoke most days for a gruelling 2½ months. On Aug. 5, 2014, PM2.5 levels peaked at 873 micrograms per cubic metre – almost 100 times greater than the current national ambient air quality standard.
Dr. Howard went on to become the lead author of a years-long Health Canada-funded study on the 2014 forest fire season. A collaboration between the Yellowknives Dene, the Ka’ga’a Tu First Nation, Ecology North, Yellowknife physicians and academics in southern Canada, the study titled SOS! Summer of Smoke was published this past February in the peer-reviewed open-access journal BMJ Open.
The study found that the 2014 smoke event was associated with a doubling of emergency room visits for asthma, as well as primary-care visits for pneumonia and cough, compared to previous summers. There was also a 48-per-cent increase in community dispensation of salbutamol, which eases breathing during acute episodes of various respiratory conditions.
“We know forest fires are going to get worse,” Dr. Howard said. “We’re going to have our hands full getting people through this in a healthy way.”
But as fire seasons get longer and more intense, so, too, will the periods of smoke. Research is under way to better understand the long-term implications of repeated and prolonged seasonal exposure.
For 41-year-old Yellowknife resident Charles Kalnay-Watson, the consequences are clear, if anecdotal. Mr. Kalnay-Watson, a senior policy analyst with the territorial government, has asthma. For years, he managed the condition with a twice-daily dose of medication. He only rarely had acute episodes requiring supplemental salbutamol treatment. But after enduring the 2014 forest fire season, Mr. Kalnay-Watson said his lungs have never been the same.
These days, he reaches for salbutamol sometimes as often as several times a day. It was so bad one day last year that he went to the hospital. “There was before 2014 and the summer of smoke,” he says, “and there was after.”
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Active wildfires were still burning near Lytton when The Globe and
Mail's photographer visited on July 9.
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“The warmer we get, the more fire we see, the more peatlands burn, the more
carbon is released, feeding the warming,” Dr. Flannigan said. Fires and
warming temperatures also promote the thawing of permafrost in the North,
causing the release of powerful greenhouse gases such as methane.
Wildfires, Dr. Flannigan noted, are a necessary part of nature. They release
nutrients stored on the forest floor and can promote new growth that supports
diverse wildlife species. Still, intervention is required when communities or
infrastructure are under threat. The image of helicopters dropping fire
retardant on massive flames may come to mind, but in some cases that approach
may be futile. Once a fire reaches a certain level of intensity, Dr. Flannigan
said, an aerial attack is akin to spitting on a campfire.
One approach that can be effective in reining in intense wildfires is known as
backburn – setting a controlled fire that backs into the prevailing wind in
the path of an approaching wildfire. The low-intensity backburn consumes fuel
in a managed way before a high-intensity, out-of-control fire gets the chance
to burn it. “The fire goes out because there’s no fuel,” Dr. Flannigan said.
But while the technique is effective, it can also be risky,
particularly in mountainous regions such as Western Canada, where the wind
direction can shift quickly and turn the backburn into a new out-of-control
fire.
In anticipation of forest fire season, some jurisdictions will engage in
prescribed burning, in which a patch of land is purposefully burned and the
fire is monitored and controlled. This practice stems from the principle that
an out-of-control wildfire that bumps up against land that has recently been
subject to a prescribed burn will start to dwindle. Burned land is unlikely to
burn again for 10 to 20 years.
“It may seem counterintuitive to fight fire with fire,” a report released last
month by the Global Climate and Health Alliance says. “However, fire is used
in carefully controlled ways by Indigenous communities around the world.”
The report, The Limits of Livability: The Emergency Threat of Smoke Impacts on
Health from Forest Fires and Climate Change, recommended that wildfire
agencies work with and learn from Indigenous fire managers.
One such Indigenous fire manager is Russell Myers Ross, the former chief of
Yunesit’in First Nation, one of six communities within the Tsilhqot’in Nation
in central B.C. Mr. Myers Ross is the community’s main liaison with Gathering
Voices, an Indigenous-led charity that’s supporting a project aimed at
revitalizing traditional fire management in the territory.
“Indigenous people have been using fire as a way of managing the land for
hundreds, if not thousands, of years,” Mr. Myers Ross said. “For us, it’s a
chance to revitalize that knowledge.”
As hundreds of out-of-control fires burn in Canada, the probe into what
ignited the fire in Lytton continues. Investigators with the federal
Transportation Safety Board are examining whether a freight train sparked the
fire, which killed two people. Over the weekend, Transport Canada halted
railway traffic around Lytton as residents were granted temporary access to
what’s left of the devastated town. It has all but been reduced to rows of
charred vehicles, piles of bricks and twisted metal, and snarled twigs that
were once trees.
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Links
- Canada Just Had Its Hottest Temperature Ever Recorded
- Dozens Dead as Canada Hits Record High Temperature For Third Straight Day
- Climate change means even more parts of Canada will need to prepare for stronger hurricanes, report suggests
- Climate change disasters in B.C. likely to increase if industrial logging continues unchecked: report
- Scores dead as record-breaking heat wave grips Canada and US
- Nowhere is safe, say scientists as extreme heat causes chaos in US and Canada
- This heat wave is just the start of what Pacific Northwest workers will face with climate change
- Is climate change amping up the Pacific Northwest heat wave? Yes — and it’s time to stop asking.
- NASA Reveals Shocking Ice Cap Melt in Antarctica After Record Heat
- We've learned a lot about heatwaves, but we're still just warming up
- Explainer: climate modelling
- 'Good people fall victim to doomism. I do too sometimes' - Climatologist Michael E Mann
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