Wildfire in a Warming World

In August 2021, I stood with my wife and two teenage daughters at the northern terminus of the Superior Hiking Trail. It was a hot and dry summer. We hoisted our packs and started hiking south, winding through woods, across ridges, into valleys. We stopped at overlooks to admire the blue of Lake Superior on one side and the endless green forests on the other.

Not long after we started, I heard news on the weather radio about a forest fire that was growing fast. The Greenwood Fire had been started by lightning and was proving hard to control. It was, The New York Times would report, moving “like a freight train.”

Samantha Sparks is a firefighter for the U.S. Forest Service who was sent out right away on the “initial attack” phase of fighting the fast-moving blaze.

“The Greenwood Fire was one of those fires where it was the perfect conditions,” Sparks says. “Everything lined up and it went big. It was a large-scale fire, so they pulled in resources from outside the state and around the country to help.”

Sparks and her crewmates were sent to visit homes and cabins in the area, guided by information from surveillance aircraft, to prepare for evacuation. When more firefighters arrived from within and beyond Minnesota as part of the Minnesota Incident Command System’s wildfire response, Sparks was dispatched back to Ely to deal with other fires.

Evening fell across the Sawtooth Mountains as we pitched our tent next to the Superior Hiking Trail. Before going to sleep I checked the radio to see how close the fire was. I’d heard stories of the 2011 Pagami Creek Fire in the Boundary Waters, which was pushed by 35 mph winds and sent campers fleeing for their lives. Learning that the fire was in the vicinity of Isabella, more than 60 miles to the southwest, was only mildly reassuring. Drifting off, I wondered what we would do if we heard a roar coming over the hill.

Summer of Smoke. Though the Greenwood did not end up being a danger to us, it grew into a large and long-lived fire, torching nearly 27,000 acres. It destroyed 70 homes, cabins, and structures—but took no lives—before being declared out in December.

That year saw more than 2,000 wildfires—nearly twice as many as in recent years—which burned some 69,400 acres across Minnesota, and fires from Ontario, Manitoba, and the western United States triggered air quality alerts, forcing us all to become acquainted with the Air Quality Index. The warmest months of 2021 became known as the “summer of smoke,” and we could smell it.

Since then we have seen two more consecutive summers with widespread drought, and in 2023, we were again blanketed with smoke from Canadian wildfires. That summer, “megafires” in Canada burned more than 44 million acres and 150,000 people were evacuated from their homes, while wildfires in Hawaii killed more than 100 people. Europe had its worst fire season in decades.

Here in Minnesota, watching the news and smelling the smoke pouring down from Canada, it sometimes seemed like much of the world was burning, and that as the climate warms, fire is in all of our futures.

But the reality is more complex, and in Minnesota there are reasons for both hope and caution. From a historical perspective, the state is safer than a century ago from catastrophic wildfires, thanks to a changed logging industry, better prevention and preparedness, and improved firefighting technology and tools. And prior to recent drought-prone years, Minnesota experienced an extremely wet decade from 2010 to 2019, which helped reduce the risk of wildfire during that period. Regardless of improved fire management practices and recent wet/dry cycles, one thing is certain: The warming world, with its continued unpredictability, will color the state’s fire forecasts for the foreseeable future.

Fire Season, Climate Links. One observation comes up over and over when talking with Minnesota wildfire responders: The fire season is getting longer. 

“Over the last 10 years we’ve definitely seen an increase of the longevity of our fire season,” says Nick Petrack, forest fire management officer for the Superior and Chippewa national forests. “We always have a spring fire season in Minnesota. It’s just arriving about six weeks earlier than we normally would see.”

That was certainly true this past spring, when a dry fall and winter gave way to a crisp, brown landscape with ready-to-burn vegetation. Eight fires broke out on March 3 alone, kicking off another early start to the fire year in 2024.

Apart from the long-term trend of a lengthening fire season, Minnesota DNR predictive services coordinator Travis Verdegan is watching another notable trend in the past few years: flash droughts, which appear and intensify quickly.

“Predictions from climate science say we’ll have more flash droughts and flash floods,” says Verdegan. “And we’ve seen that.”

“In the 2020s, we’ve had flash drought episodes at least three times already, which is a lot,” says climatologist Kenny Blumenfeld of the DNR’s Minnesota State Climatology Office. “Since 2020, we’ve had much drier growing seasons than we had the previous decade. And that’s been especially prominent in the period May through July.” So far in the 2020s, he says, “We’ve had conditions that have been more fire prone, just based on the climate being warm and dry or hot and dry, than we saw during most of the 2010s.” That decade, in stark contrast, was particularly rain-soaked—“the wettest decade on record,” says climatologist Pete Boulay, also of the State Climatology Office.

These recent years of flash droughts have brought more summer fires.

“Normally in Minnesota we have a bimodal fire season,” says DNR statewide wildfire operations supervisor William Glesener. “We have a pretty significant fire season in the spring, then it would pretty much shut down with green-up and start up in the fall. Lately we’ve noticed that with these droughts in the spring lingering into the early summer, the fires don’t end like they had in the past, and summer is starting to replicate the fall.”

This was especially evident in 2021, when the Greenwood Fire, the John Ek Fire, and the Whelp Fire closed the Boundary Waters Canoe Area for the first time since the 1970s.

So do these recent drought-prone years represent a shift of the pendulum back toward dryness after the waterlogged 2010–2019 decade? In climatological terms, they don’t yet add up to a turnaround, says Blumenfeld, who takes a bigger-picture perspective.

“When you look at the long-term pattern, the dry years of the early 2020s look like a normal variation from a long-term trend toward wetter years [in Minnesota]. And even when you include the dry years of the 2020s, we still see a long-term trend toward increasing annual precipitation.

“What that means is that we either haven’t had enough dry years yet, or they haven’t had great enough departures from the long-term trend, to reverse the trend toward increasing precipitation.”

But, he adds, “If every year this decade ends up really dry, that would change that statement. Even two or three more dry years would probably change that statement.”

A History of Fire. The history of wildfire in Minnesota goes back as far as the forests and prairies themselves: Fire has always been a natural part of these ecosystems.

But the story of wildfire also includes some tragic chapters: In 1894, the Hinckley Fire burned 350,000 acres and killed 418 people. In 1910 the Baudette Fire burned 360,000 acres and killed 27, and in 1918, the Cloquet and Moose Lake fires burned 250,000 acres and left 453 dead and thousands homeless.

Since then, we’ve come a long way toward preventing such catastrophic wildfires, and even though Minnesota’s fire season is getting longer, the overall wildfire trend has been downward over time. The 2011 Pagami Creek Fire in the BWCA that burned nearly 93,000 acres was the biggest wildfire in living memory, yet it was only a quarter of the size of the Hinckley Fire, and no one died. The 2007 Ham Lake Fire burned 75,000 acres and destroyed 133 structures, including 61 homes. But again, no one died.

One reason for the change is better logging practices and modern forest management. Those huge fires of a century ago were caused in part by extreme clear-cutting that left vast expanses of ready-to-burn fuel. We don’t leave logging slash lying around anymore, and forest managers try to reduce fuel loads in forests with practices such as prescribed burning.

From the 1980s until recently, Minnesota’s number of wildfires and acres burned varied from year to year depending on conditions, but the overall trend was relatively flat. Then about 15 years ago, when wildfires were increasing in other parts of the country, Minnesota’s started going down.

One reason has been climatological: that extremely wet 2010–2019 period. Another reason has been an especially effective approach to preventing human-caused fires, which is key, given that more than 90 percent of fires are caused by people.

“Since the late 2000s,” says Verdegan, “we’ve seen a steady decline in our wildfire occurrence trends, which we can attribute to a successful prevention program in our burning permit system. We knocked out a lot of preventable fires from what we would have seen.”

Karen Harrison, DNR state wildfire prevention specialist, says, “In Minnesota, most wildfires are caused by escaped vegetative debris burning.” The burn permit system tells people when weather conditions lower the risk, and it lets agencies know someone is burning. It helps keep people informed and safe, and it helps firefighters, so they don’t spend time and resources responding to a permitted fire unless it escapes.

In her prevention work, Harrison emphasizes that people shouldn’t leave fires unattended and should ensure they’re out cold by drowning them with water, stirring, and repeating. Vehicle owners should park on gravel or pavement so the exhaust system doesn’t ignite dry grass. Drivers with trailers should make sure their tow chains are hooked up properly, since sparks from dragging can start a fire. And if you see a wildfire, call 911: Don’t try to put it out yourself.

Yet even with all these guardrails, the human element remains the wild card with wildfire, says Harrison.

“We can understand wildfire potential,” she says, “but what we can’t do is predict how many wildfires there are going to be, because often that comes down to people and their choices.”

New Tech and Tools. Several advances in firefighting communications, technology, and equipment have made Minnesota wildfire responders able to respond more quickly and effectively to fire.

One big step forward came in 1984, when the Minnesota Incident Command System was put in place. This created a center for coordinating the response to wildfires. So instead of trying to decide whether a fire was in a state forest or a national forest or a national park, agencies could send responders to attack the fire right away. This system was one of the first in the country, and other states are starting to emulate it.

“MNICS was able to take away those imaginary boundaries,” says Leanne Langeberg, public information officer for the Minnesota Interagency Fire Center, “and send the closest resources to respond to a fire.” It also lets agencies at all levels train their firefighters to national standards.

There has also been a stream of technological advances in fire detection in the digital era.

“We have remote automated weather stations all across the state that report back through the satellite system,” says Glesener. “Then we put those numbers into software that can do fire behavior modeling and predict what our flame lengths and rates of spread are going to be in any given area.”

Other innovations include lightning detection and satellite imaging—though 911 calls often come in before satellite data gets there, Glesener says.

When it comes to the nitty-gritty of fighting fires, Minnesota has some powerful new tools. One game changer has been the FireBoss, a firefighting plane invented in Minnesota. In 2003, Bob Wiplinger had the idea to take an Air Tractor crop duster, put special pontoons on it, and use them to fill the tanks with water instead of herbicide. The FireBoss skims along a lake at 60 mph and in 15 seconds sucks up 600–800 gallons of water to drop on a wildfire. Its first use was in Minnesota in 2007.

Meanwhile, on the ground, the All Track AT-50 and AT-20 are small, tank-like vehicles than can haul a couple hundred gallons of water. And firefighters sometimes deploy handheld thermal imaging devices that detect infrared heat.

In another advance, this year, for the first time, all the agencies involved in fire response, from the DNR to the U.S. Forest Service to the Bureau of Indian Affairs and the U.S. Fish and Wildlife Service, will be linked by a statewide computer-aided dispatch system.

“Now all of our areas and dispatch offices are essentially connected by one system,” says Glesener, “so that if something is emerging that’s going to be complicated, everyone has access to the same information and can all know who, what, when, where, and how. That speeds up the information transfer and is where the efficiencies really start coming in.”

Global Fire Risk: Up and Rising. Even the most sophisticated firefighting response will be doing just that: responding to the global climate trends shaping the future of wildfire.

In many parts of the world, the impact of global warming is clear. Researchers from World Weather Attribution concluded that in Canada, climate change is making “peak fire” weather twice as likely. In the western United States, a Forest Service study found the amount of western land burned by “high-severity” wildfires has increased 800 percent since 1985. A study published in Nature in 2022 concluded that, across the globe, wildfire in areas with frequent, fire-prone conditions would increase by 29 percent and that climate change would significantly lengthen the fire season.

Even if Minnesota is still in a long-term wet period that’s temporarily on pause, Blumenfeld again looks to a broader perspective when talking about the future of fire.

“In climate change science, it’s pretty unambiguous that in North America and around the world, overall wildfire risk will increase,” he says. “So maybe Minnesota will continue to kind of be buffered and have some of its worst risks offset by wet conditions from fall into spring. But overall wildfire risk is expected to continue increasing on a continental and on a global scale.”

On Alert. My family’s hot, dry trek in 2021 felt like a portent of this warming world. All summer we’d been hearing about wildfires in the news, so it was heavy on our minds. Now a fast-moving fire was racing in our direction.

Wearing our backpacks, we hiked south on the Superior Hiking Trail for three days to Judge C.R. Magney State Park, where we had parked our car. The air was hazy from the Greenwood Fire, which our radio told us had continued to spread. As soon as we got off the trail, I felt a wave of relief. 
Ten days later, we learned that the Superior Hiking Trail had been closed to camping due to wildfire, along with the Boundary Waters and dispersed and backcountry camping in several state parks and forests.

Minnesota entered the 2024 fire season after a multiyear drought that has fueled the critical fire weather factors: high temperatures, high winds, and sunny, dry days with relative humidity below 25 percent. Will we see a repeat of those conditions this summer?

In the past, Minnesota’s fire season ended with the first big snow. But in fall 2023, that snow never came, which meant the spring 2024 fire season started even earlier than usual. It also was more widespread.

“Traditionally in late March to early April we start to see a steady rise in wildfire activity, and that goes south to north,” says Harrison. “This year, it’s not just that it started earlier, but it started across the state. We were seeing fires everywhere from the south up to the northwest.”

Late spring brought welcome rains across the state, but we have yet to see what summer holds. If conditions turn the state into a tinderbox again, our state’s wildland firefighters will be on high alert, and anyone in the outdoors should be mindful of fire.

“Even though fire numbers overall are dropping, we know fire potential still remains,” says Verdegan. “We may not have as many fires, but that doesn’t mean that we still can’t have a destructive fire.”