Canadian firefighter Scott Rennick knew this summer would be bad. It was May 2023 and Rennick was commanding one of British Columbia’s six incident management teams, or IMTs, specialized crews tasked with managing the most complex fires. His 18-person crew had just arrived in the northeast city of Fort Saint John to fight an aggressive bushfire. The province’s wildfire service was still in the midst of hiring, training, and recruiting when the human-caused fire was discovered on Saturday, May 13. By Sunday, flames had spread over 7,000 acres. By Monday morning, it had multiplied fivefold and now covered an area roughly the size of Staten Island. But the worst was yet to come.

Drought had already rendered the land hot and dry. The third ingredient for a natural-disaster-level fire was wind. That came Monday afternoon as a cold front pushed directly into its path, creating gusty 25 mph winds. In a few hours, the blaze spread 9 miles in various directions, approaching Fort Saint John, British Columbia’s oil and gas capital with a population of 21,000.

Rennick says the terrifying glory of a firestorm—ferocious fires fueled by powerful winds drawn into the flames—never ceases to amaze, even after 30 years on the job. It sounded and moved like a freight train, sucking up tens of thousands of pounds of oxygen as it swallowed everything in sight. For 18 straight hours, Rennick and his crew fought alongside dozens of firefighters and heavy equipment operators to create firebreaks wide enough to catch flying embers. Then, exhausted, they rested.

At the ad hoc incident command post, Rennick looked up the three-month forecast on his laptop. Western Canada was covered by a deep red blob—low precipitation, warm temperatures. Later, as the commander relayed the weather report to his crew, someone asked him how many deployments he predicted that season. A typical summer is four. Rennick held up six fingers. “Hopefully I’m wrong,” he added.

As of this week, Rennick’s crew were returning home from their fifth deployment, tackling one of 1,050 active wildfires in Canada—fires becoming bigger, hotter, longer lasting, and more frequent than ever before. He’s already gearing up for his sixth deployment, and with up to six weeks left in the wildfire season, a seventh is likely.

Rennick, who grew up in the city of Vernon in British Columbia, has battled fires most of his life—as did his father and grandfather. “This is just a very different environment we find ourselves in now,” he says. “People who don’t believe in climate change can come talk to me.” At the time of writing, British Columbia is in the midst of a province-wide state of emergency. Up to 200 buildings are estimated to have been destroyed by wildfires in the Okanagan region. And the fires are still burning. “In that kind of extreme situation, it’s no different than trying to put your hand in front of a tsunami or a hurricane and say, ‘Stop,’” says Rennick. Two years ago, during a record-breaking heat wave, he watched a grassfire engulf the town of Lytton, annihilating it in 23 minutes. And yet the intensity and frequency of this summer has exceeded anything Rennick thought possible.

In June, Rennick’s second deployment of summer 2023 took him to the town of Edson in Alberta, where his IMT joined hundreds of firefighters from as far afield as Australia in a battle against a campaign fire. This type of inferno, once rare but now alarmingly common, is so large and so powerful that it can take months of aerial and ground operations to contain. Campaign fires can even survive a Canadian winter, smoldering under the snow as temperatures fall to minus 60 degrees Celsius before bursting back to life as zombie fires in the spring. At one point, smoke from the fire near Edson formed pyrocumulonimbus clouds that injected a plume of soot 31 miles up into the stratosphere, which then traveled around the globe.

Formed by only the extreme wildfire conditions, pyrocumulonimbus clouds, or pyroCbs, are a firefighting nightmare. They can generate lightning, thus igniting more fires; they create windstorms that spread the blaze; and, though rarely, they can create “firenados,” pyrogenic vortex columns that can reach heights of 3,000 feet and speeds up to 140 mph. Like campaign fires, pyroCbs were a once novel phenomena more often associated with volcanic eruptions. The US Naval Research Laboratory only started tracking them a decade ago. A typical year sees 40 or 50 worldwide. The previous record, set in 2021, was 100. By August of 2023, Canada alone had generated 133 of 153 pyroCbs observed by the NRL. “This,” says Rennick, “is the most unprecedented season in the history of the country.”

Unprecedented doesn’t even begin to describe what Canada is up against. Close to 6,000 fires have scorched 34 million acres, an area the size of New York State, according to the Canadian Interagency Forest Fire Centre. That’s three times bigger than anything ever recorded in the US, and 10 times the 10-year average for Canada, which, historically speaking, was already well above average. Over 150,000 Canadians are currently displaced, including two-thirds of the population of Northwest Territories and, at the time of writing, 35,000 people in British Columbia.

The speed of change is being driven by a warming world. A warmer world means more moisture is sucked from the ground, resulting in drier fuels. The drier the fuel, the easier it is for a fire to start and spread and burn with greater intensity. That moisture being sucked from the ground also creates more thunderstorms. With this comes more lightning, which is responsible for starting half of Canada’s wildfires. These fires, due to their remoteness, account for 90 percent of the area burned in Canada. Many of these fires aren’t just hard to reach—they’re hard to even detect. This gives them more time to spread, with many fires in remote areas of Canada monitored rather than extinguished.

So much of Canada is burning, and so quickly, that the seed banks needed for forest regeneration work could be stripped bare within years. But disappearing forests won’t mean fewer wildfires, as repeatedly scorched land will become fire-prone grasslands and shrublands. If this summer becomes the norm, rather than the exception, the ecosystems that humans depend on for clean water, pollinators, and food will be altered—with unknown consequences. “We don't really know where it’s going, and that is very frightening,” says Daniel Perrakis, a fire research scientist with Natural Resources Canada.

With fire comes smoke. As wildfires have torn through Canada, much of North America has choked under a cloud of noxious air. To date, Canada’s fires this summer have emitted 1 billion metric tons of carbon dioxide, a quarter of total global fire-carbon emissions so far this year. This has made Canada, a country of 40 million people, the world’s fourth biggest polluter. In 2022, Canada ranked 10th on that list.

That smoke affects the health and well-being of the whole planet. But it poses a particular risk to those living in some of North America’s most populous cities, who have experienced unprecedented levels of air pollution in recent months. As a result, Canada’s firefighting competence is being scrutinized as nations deploy hundreds of their own firefighters to the country, while also pressuring Ottawa to get a grip on the crisis.

In June, the east coast of North America struggled through days of dense smoke pushed south from Quebec. Toronto’s CN Tower vanished, and Manhattan was painted a dense, Blade Runner-esque orange. The smog was so thick that the Port Authority of New York and New Jersey limited driving speeds on bridges.

The smoke, which originated from fires burning 750 to the miles north, soon covered an area of North America home to more than 145 million people. Across much of the Northeast of the US and southeastern Canada, the Air Quality Index, which government agencies use to measure pollutant levels and health risks, shot from between 50 and 70, a healthy to normal range, to over 400—on a scale that maxes out at 500. Emergency health warnings persuaded many people to stay indoors. Stock prices at air filtration manufacturers rose by as much as 15 percent.

The wildfire smoke from Quebec sat in the atmosphere for weeks, spanning the Atlantic Ocean and dimming skies as far away as Portugal. For many on the east coast of North America, the orange skies of June were a wake-up call. For more than a decade, increasingly severe wildfires had ravaged North America’s West, from California in the south to Alaska in the north. Now, the age of flames had arrived in the east.

When it comes to wildfire smoke, the biggest danger is PM 2.5, the fine particulate matter that gives the sky a haunting orange hue. “When you breathe these very small particles, they can make it deep into the lungs, right down to the alveolar oxygen exchange region,” says Sarah Henderson, the science director for the National Collaborating Centre for Environmental Health in Canada, who’s been studying the health effects of wildfire smoke for more than 20 years. “Then we get inflammation that can affect all organ systems in the body.”

There are still many unknowns about the long-term consequences of inhaling wildfire particles, Henderson says, in part because sustained exposure is a relatively new phenomenon. A 2022 Lancet article examining Canadian data over 20 years linked wildfire exposure to slightly higher rates of lung cancer and brain tumors; however, the researchers said more data was needed.

Still, there’s reason to believe that even occasional exposure can have repercussions that last a lifetime, especially in children. By examining the long-term effects of other sources of air pollution, Henderson says there’s reason to believe that wildfire smoke might affect respiratory, neurological, and prenatal health. A Stanford Medicine study of children from Fresno, California, who were exposed to smoke from two large wildfires in 2014 found negative effects on immunity-related blood cells and genes.

“We have to go into every wildfire season with the idea that it might be the worst season we've ever seen—and that includes both wildfire risk and smoke,” says Henderson. “That is the reality of the changing climate and the wildfire regime in Canada.” To that end, she thinks officials may need to consider rewriting building codes to insulate against indoor smoke penetration.

Mike Flannigan, science director of the Canadian Partnership for Wildland Fire Science and a professor at Thompson Rivers University in British Columbia, calls this summer a “wake-up year” for Canada, which has struggled to curb its wildfire crisis due to a lack of a nationwide strategy, funding, and political willpower. “We're going into uncharted territory. And we're going faster than I would have thought possible,” he says.

As a result, Canada needs firefighters—lots of them. With 5,500 wildland firefighters, about 5.5 per fire at the moment, Canada has called in international fire crews from the southern hemisphere and the Pacific Northwest of the US to help. But even with the assistance of thousands of foreign firefighters, Canada has struggled to procure enough air tankers to water-bomb new fires in the critical first few hours. And so the officials tasked with fighting Canada’s wildfires have been forced to choose, allowing many fires to spread unless they pose an immediate threat to human life or critical infrastructure.

This week the Globe and Mail reported that Canada’s foreign workforce was 680 firefighters, down from 1,754 in July. That fall has been attributed to contracts expiring, but also to firefighters needing to return home to fight fires raging in their own countries. Flannigan believes Canada needs to hire 2,500 more wildland firefighters within its borders to meet current needs. But this is an industry plagued by high attrition rates, due to mental burnout and a predominantly seasonal and volunteer workforce. A 2016 report from Ontario FireRanger, the province’s wildland firefighters, found that the organization was “stuck in a cycle of continuously reiterating basic training” due to high turnover.

Things haven’t improved much since. On top of working 12 to 16 hour days for weeks on end, this year Canadian firefighters have faced extraordinary danger. On-site fatalities are almost unheard of in Canada, but four firefighters have died this summer, including two in British Columbia. Rennick says the unrelenting season has made it difficult for his colleagues to process the emotional toil. “Once myself and my colleagues stop and they go back to their regular jobs or part-time jobs, the full gravity of the season will hit us,” he says.

In a normal year, Rennick would expect a staff turnover of 20 percent, but next year will certainly be higher. To that end, Natural Resources Canada recently allocated CA$37.9 million ($27.9million) to recruiting, training, and retaining firefighters in high-risk zones. But several experts and politicians, including Flannigan, want federal officials to go further and are calling for the creation of a national firefighting service.

At present, there’s no single national strategy guiding wildfire management in Canada. A patchwork of provincial, territorial, and national park units instead share resources via the Canadian Interagency Forest Fire Centre. But the center, founded in 1982, has been overwhelmed by the scale of the current crisis. Historically, Canada’s wildfires were staggered across both time and geography. Now, huge fires are occuring well out of season and in regions previously less affected, including the Maritime Provinces and Northern Quebec and Ontario, all while the country struggles to increase and update its fleet of aging water bombers.

Coordination between woodland and urban firefighters is another challenge. In 2016, a fire at Fort McMurray in Alberta showed what happens when communication breaks down. The Beast, as it came to be known, took locals by surprise, resulting in a last-minute evacuation of 88,000 people on a single highway through flames and embers. An inquiry into the most expensive natural disaster in Canadian history reported that local and provincial authorities weren’t even sharing the same radio frequencies. “This was particularly problematic when it came to air attack,” the report found. “Alberta Forestry aircraft had no way to forward a direct message to municipal firefighters.” When the fire did reach the city, local emergency management learned about it from social media.

Such catastrophes, combined with this record-breaking summer, have also led Canada to consider the creation of a bureau similar to America’s Federal Emergency Management Agency (FEMA). In June, Bill Blair, then Canada’s emergency preparedness minister, told the CBC that his government had begun discussions with the head of FEMA about creating a Canadian equivalent, as well as a joint agency similar to the North American Aerospace Defense Command, or NORAD, to manage cross-border emergencies—including wildfires.

Public Safety Canada, the country’s closest equivalent to FEMA, struggles to address large-scale events because of its broad focus, of which only a small part is dedicated to emergency management. The agency  spends just $4.70 per Canadian for national emergencies, compared to FEMA’s budget of $87.87 per American. Public Safety Canada’s primary role this summer has been to deploy the armed forces to assist in building fire breaks and assist in evacuations.

Wildfires have long been a part of the Canadian landscape, but urban development over the past 70 years, especially in the west, have created a new problem. Today, more people than ever are living right next to nature, with forests butting right up against new urban developments. The staggering destruction and death toll of fires in Paradise, California, in 2018, and this month’s tragedy on Maui, were partly attributed to the intermingling of urban development and vegetative fuels.

Despite its vast size, Canada faces similar problems. “We’re reaching a point where creation of some agency like FEMA has become a necessity,” says Ali Asgard, a disaster and emergency management professor at York University in Toronto. He adds that Public Safety Canada, or perhaps a future emergency management agency, also needs to do more to prepare communities for managing hazardous pollution levels. As smoke and flames cross the southern border, pressure is mounting on Canadian officials to ensure there isn’t a repeat of this summer—or worse.

Like the climate crisis itself, managing the wildfire crisis is politically complex. Though fire suppression tactics have changed over the past two generations, Canada is currently dealing with a fire deficit of 100 to 150 years. This has created an oversupply of tinder that should have been cleared long ago by healthier fire cycles.

Fire plays an important ecological role in the dense, carbon-packed boreal forests that cover more than half of Canada and 14 percent of the world, something many Indigenous people have long understood. Fires can help reduce pest infestations, open water channels, and improve soil health. But Canada’s woodlands changed with industrial techniques that extinguished fires with full force, resulting in more overgrown, homogenous, and flammable landscapes.

Some of the most effective prevention techniques are also highly unpopular, such as preemptive fire bans and forest closures during high-risk periods, because they interfere with camping, hunting, and other recreational activities. Even more controversial is the tactic of prescribed fires—literally fighting fire with fire, by ridding forests of flammable underbrush during low-risk times, or back-burning during active fires to prevent wildfires from spreading.

Controlled burns can be politically challenging, especially during an active firefight, when the public is sick of breathing smoke or concerned about prescribed fires going rogue. But, explains Amy Cardinal Christianson, a Metis scientist and Parks Canada’s Indigenous fire specialist, controlled burns are one of our best tools, because they essentially replace fires of chance with fires of choice.

Cardinal Christianson’s role at Parks Canada, the federal agency charged with protecting the country’s natural and cultural heritage, is to work on partnering with Indigenous communities to apply burning practices that have been suppressed by colonization. “Indigenous people have always been trying to push to be more involved in fire management in Canada and especially in having cultural fire on the landscape,” says Cardinal Christianson.

Such practices are often family-oriented, involving children and elders, and range from burning the underbrush while there’s still snow on the ground to burning an overgrown bush to protect a berry patch. Since colonization, government regulators have suppressed much of this knowledge, but many First Nations have never stopped treating the land with fire—they just went underground.

Today, many of Canada’s Indigenous people are frustrated with governments’ “two-tiered system,” which often prohibits cultural burning while appropriating Indigenous fire knowledge for use on massive prescribed fires. “There’s a lot of concern that agencies will come and extract the knowledge that they want and put it into their agency practices, but then Indigenous people still won’t be at the table,” says Cardinal Christianson.

The frustration among Indigenous Canadians is amplified by the disproportionate impact of wildfires on their communities. A recent study by Cardinal Christianson and her colleagues examined Canadian evacuations from all causes spanning 1980 to 2021. The researchers found that 37 percent of people on First Nations reserves have already survived at least one wildfire evacuation. Moreover, Indigenous communities comprised nearly half of all fire evacuations in Canada, and nearly all smoke evacuations, since 1980.

Across North America, many people are only now beginning to understand the threats from fire and smoke that people in the other half of the continent have faced for centuries, but with increasing and intensifying regularity. The prognosis is grim. More land will burn, more people will be displaced, many more again will breathe toxic air. But, beyond that, says Flannigan, if fires on this scale continue, the forest they are burning through will soon vanish entirely.

Yet the fires that have burned across Canada this summer, and continue to burn, won’t become the “new normal,” says Flannigan. Instead, he says, things will only get worse. “I often use Dante’s circles of hell,” he says. “I’m not sure what circle we're on—three, four?—but there's more circles below us, and that's where we're going.” This summer has made the urgency of the situation unavoidably clear: Canada, and the world, needs a plan—and fast.

Update 8-24:2023 2:17 PM ET: This story has been updated to correct the figure for metric tons of carbon dioxide emitted by Canada's fires this summer.