The Globe and Mail explores some key questions as Canadians endure weather that one climatologist described as ‘almost biblical’.
The B.C. village that set a Canadian heat record last week, at a scorching 49.6 C, went up in flames beneath a high-pressure weather system wreaking such havoc that one climatologist described the situation as “almost biblical.”
First came extreme heat in the Fraser Canyon town of Lytton, then came the wildfires – a cascade of climate-change disasters that has captured international attention. “Heat records are usually broken by tenths of a degree, not 4.6 C,” Swedish climate activist Greta Thunberg tweeted, referring to the previous Canadian high of 45, set in Saskatchewan in 1937. “We’re in a climate emergency that has never once been treated as an emergency.”
In the Pacific Northwest, wildfires are burning, power grids are failing, transit systems are melting and people are dying. Between June 25 and June 30 alone, the BC Coroners Service received 486 reports of sudden and unexpected deaths – a 195-per-cent increase over the approximately 165 deaths the service would see in a typical five-day period. Once locked over the West, the system has moved eastward, with Environment Canada heat warnings in effect in parts of Ontario and severe thunderstorm warnings in southern Quebec.
“People ask, ‘Is this the new normal?’ ” said Courtney Howard, an emergency physician in Yellowknife and former president of the Canadian Association of Physicians for the Environment. “It’s not the new normal. It’s going to continue to get worse for the next few decades.”
While weather is naturally variable, this kind of heat event is made ever more intense – and will occur with increasing frequency – because of climate change. Here, The Globe and Mail explores some key questions as Canadians confront the loss of life and landscape.
How hot did it get in B.C.?
Why was it so hot?
Several factors conspired to keep a massive ridge of warm air parked over the Pacific Northwest last week. Meteorologists call this effect a “heat dome” because the warm air is trapped in a circulation pattern that prevents cooler air from moving in.
This year, an unseasonably dry spring in the region has served to amplify the high temperatures. With so little moisture in the environment, solar energy that might otherwise have gone into evaporating water has instead been making hot air even hotter. And while the giant weather system is heading eastward, its movement was slowed by a wavy pattern in the jet stream called an “omega block,” which allowed temperatures to soar in the same locations each day with little or no relief at night.
How unusual is this?
A heat dome is not unusual, but the scale and impact of this latest one has literally been off the charts. That much is obvious from the shattered temperature records the system produced in hundreds of locations. For example, Victoria, which has one of the mildest climates in Canada, has an average June high temperature of 20. On June 28, it reached 39.8 – a full nine degrees higher than the city’s previous record, set in 2015.
Just as striking is the scale of the high-pressure ridge, which stretches from Death Valley, Calif., to the Arctic Circle and has reached altitudes comparable with those of commercial aircraft. What weather experts say is even more astounding, though, is the fact this pattern is occurring now.
“Generally, the warmest moment of the year in a province or city comes much later, in July or August, not in June,” said David Phillips, senior climatologist with Environment and Climate Change Canada. He added that having so many temperature records broken so early in the summer, accompanied by flood warnings because of sudden snow melt on mountain peaks, has put this week in a class by itself in the annals of Canadian weather. “I mean, it’s almost biblical,” he said.
How is extreme weather connected to climate change?
More warm weather and more frequent extreme weather events, including heat waves, are among the most consistently predicted outcomes of climate change owing to human-generated fossil-fuel emissions. This certainly applies to Canada, which is projected to warm about twice as much as the global average for a range of climate scenarios, according to a comprehensive federal report published in 2019.
Western Canada is already on average one to two degrees warmer than it was in the 1940s, and this has translated into much steeper spikes in temperature during hot weather events. While heat domes occurred over the region in the past, “they were not as hot as what we are seeing now,” said Xuebin Zhang, a senior research scientist with Environment and Climate Change Canada in Toronto and co-author of the federal report.
Scientists are still debating whether climate change is exacerbating the situation in other ways, such as increasing the likelihood of the blocking pattern that has held the hot, high-pressure air over the West for so long. But there is little doubt that the trend points to more heat waves in the future – and not only in the West.
“I think we are just as vulnerable [in the East],” Dr. Zhang said. “Heat waves that are similar to what we’ve had in the past will hit us harder.”
Mr. Phillips said the likely outcome is more heat, more often. It took 83 years for Lytton to set Canada’s new high-temperature record, he said. “I think what we can learn from this is that it won’t be 83 years before we see something like this again.”
How dangerous is the heat?
The World Health Organization has identified climate change as the biggest threat to human health in the 21st century. The Lancet medical journal echoed that warning, pointing specifically to rising heat and extreme weather events. Here in Canada, the Canadian Institute for Climate Choices has predicted that heat-related hospitalization rates will increase at least 20 per cent by mid-century.
Dr. Howard, the Yellowknife physician, said heat-related health issues can range from “fun-in-the-sun annoyances to life-threatening disease.”
Toward one end of the spectrum is heat edema, or swelling in the legs (put up your feet and get cool), and heat rash (try an antihistamine to help with the itch).
Toward the other is concerning changes in vital signs, including an elevated heart rate and low blood pressure, and symptoms of heat stress or heat stroke, such as dizziness, headache, weakness and trouble thinking. “Your brain likes to be at a given temperature, so once it gets hot, it stops processing well,” Dr. Howard said. “That’s a sign that the person’s body is having trouble coping.”
Particularly vulnerable to heat-related illnesses are elderly people, who have a weaker thirst drive and don’t sweat as readily; people who take anticholinergic medications, which can cause dryness of the mouth and increased heart rate (Benadryl is an example); people with pre-existing health conditions such as high blood pressure or respiratory issues; those with cognitive issues, who may not immediately recognize or act on signs of stress in the body; those with mobility issues, who may find it hard or impossible to move from a hot space to a cool one; and people experiencing homelessness or of lower socio-economic status, who may not have access to cool spaces.
Extreme heat can also affect sleep – and, potentially, job performance.
Dr. Howard said a friend of hers, a surgeon, recently checked herself into an air-conditioned hotel because she was sleeping so poorly at home; she wanted to ensure she was well rested and able to safely operate on her patients. “There’s privilege in that,” Dr. Howard said.
What does this mean for forest-fire risk?
Fire experts say the excessive heat in the West has created a dangerous situation – something that has already become apparent in Lytton, which lies in ruins.
There have already been more than 630 wildfires in B.C. so far this year that have burned about 83,000 hectares of land. That is already more land burned than in all of 2019 and 2020 combined, and more than three times the 10-year average for early July. Roughly half of the fires this year were caused by human activity, a third were caused by lightning, and the rest are undetermined or under investigation. As of Sunday, there were 174 active fires in the province, including 13 classified as “of note,” meaning they are highly visible or pose a potential threat to public safety, according to the BC Wildfire Service.
Hot, dry, windy weather is strongly associated with fire, and the bulk of the woodland burned in Canada each year is often consumed during a few critical days of extreme fire weather. Under the high-pressure system, the extreme heat allowed whatever moisture is present to be sucked out of the brush that allows fires to start and spread easily. And while high-pressure ridges are more often associated with clear skies, local storms driven by moisture from rapidly melting snow at higher elevations can still generate lightning strikes that ignite wildfires.
“It’s basically a powder keg,” said Mike Flannigan, a wildfire expert and professor at the University of Alberta in Edmonton.
Dr. Flannigan pointed to the fires already burning in B.C. They include the one that devastated the village of Lytton, another that is closer to Kamloops and a third east of Kelowna, where thunderstorms occurred. North of Lillooet, B.C., the McKay Creek fire spread in an area just 50 kilometres west of where the Elephant Hill fire raged in the summer of 2017. That wildfire, one of B.C.’s worst, burned for 76 days, destroying more than 190,000 hectares of forest and about 120 homes.
”I’m starting to think this [fire season] looks a lot like 2017 – except it’s June,” Dr. Flannigan said.
Things could still change if weather patterns shift and more rainfall moves in, he said. But given what is more usual for the region, the rest of the summer “would have to be cooler and wetter than normal for things to settle down. The odds are it’s going to be a very active fire season.”
How does extreme heat affect infrastructure?
Amid high temperatures in late June, Calgary Transit shut down its public WiFi service at its light-rail stations to avoid damaging equipment – a minor indication that much of our transportation infrastructure was not built for extreme heat. When extremely hot, rails can bend and buckle to form “sun kinks,” which can cause derailments. In a statement, CN said it “uses advanced rail metallurgy and rail properties, along with a variety of standards, policies, and operating procedures to mitigate risks associated with thermal expansion.”
Power grids are not immune either. A 2015 study by Toronto Hydro noted that high temperatures (particularly above 40) affect power transformer capacity and electrical transmission efficiency. That can cause transformers to fail.
During the latest heat wave in the West, electricity demand skyrocketed when large numbers of people turned on their air conditioners simultaneously. BC Hydro said it was able to meet the record-breaking demand thanks to its hydroelectric dams, which can ramp up quickly. But not all utilities enjoy such flexibility; indeed, BC Hydro said its trading subsidiary, Powerex, exported so much electricity to neighbouring U.S. states lately that volumes approached the system’s transmission limits. Generally, Canada’s own interprovincial transmission capacity is even more limited, restricting provinces’ abilities to assist each other during extreme events.
Meanwhile, when the heat dome moved eastward, the Alberta Electric System Operator asked residents to conserve energy – especially between 4 p.m. and 7 p.m. – although the system has yet to fail during the heatwave.
Utilities, public transport authorities, freight railways and others are beginning to consider how extreme heat will affect Canada’s power grids, transportation networks and other infrastructure. But “I don’t think it’s been a huge focus of adaptation up until recently,” said Joanna Eyquem, managing director of climate-resilient infrastructure at the Intact Centre on Climate Adaptation. The federal government recently launched the National Infrastructure Assessment, an initiative intended to support increasing the resilience of infrastructure across the country to climate change (the public engagement process ended June 30). Extreme heat impacts are among the issues to be considered.
In addition to extreme heat, wildfires can also affect infrastructure – and not just in obvious ways. During unprecedented fires in 2014, Stanton Territorial Hospital in Yellowknife had to cancel elective surgeries for about a week because of air quality concerns in the operating room. The ventilation system, Dr. Howard said, was drawing in air – and smoke – from outside. “They weren’t thinking about that possibility when they built it,” she said. (A new hospital has since been built in Yellowknife. A spokesperson for the Northwest Territories Health and Social Services Authority said the new hospital’s ventilation system is capable of recirculating inside air, if required, to improve air quality.)
If this is bound to happen more often, how do we cope?
There are things individuals can do, and there are things companies and governments can do.
At the personal level, only about a fifth of households in the Vancouver region had air conditioning in 2017, according to the most recent Statistics Canada data. The rates in Calgary and Edmonton are only slightly higher, at 24 per cent and 29 per cent respectively – still well below the national rate of about 60 per cent. That will have to change. Cities will have to ensure they have adequate space at cooling centres, particularly for people experiencing homelessness or without access to air conditioning.
People can also install heat-resistant curtains in their bedrooms and ensure that any outdoor space they may have, including a balcony, has some greenery. Artificial surfaces such as concrete absorb and re-emit the sun’s heat more than natural landscapes – a phenomenon known as the urban heat island effect. The difference in daytime surface temperatures between urban and rural areas can be as high as 15 degrees.
“Even if you stand on your patio versus your lawn, you’ll notice a difference,” Ms. Eyquem said.
This is why cities such as Quebec have created parking lot standards that suggest ways to reduce the surface area of the lot, revegetate the space and use materials with a high solar reflective index. Cities can also protect their natural assets, such as river valleys and tree canopies, which provide cooling benefits. “We need to invite nature into the city more to help cool our urban areas,” Ms. Eyquem said.
In addition to these tangible steps to keep people and spaces cooler, Dr. Howard said Canadians must also take care of their mental health as anxiety around climate change takes hold. “It’s normal for extreme weather events like this to be a trigger for people to take a look at the world, their place in it and what climate change means for their children,” she said. “You can’t just take a yoga breath and hope for the best. You have to take action. That’s where we’re at now.”