MINNEAPOLIS — A month ago, it was smoke. Now it’s fire.
The hellish summer that has scorched more than 4 million acres west of the Rocky Mountains and sent smoke plumes drifting across the continent is no longer a Western phenomenon.
Uncontained wildfires are now burning in northern Minnesota, where homes, cabins and campgrounds are peppered through dense boreal forest where moose and wolves outnumber people.
The forests’ primary tree species, the Christmas tree-shaped balsam fir, also happens to be one of the most “explosively flammable” trees in the world, according to one expert.
Over the last four days, the Greenwood Fire in the Superior National Forest had twice doubled in size, from 500 to 2,000 acres. It continued to spread yesterday, according to a U.S. Forest Service spokesperson, with flames riding atop extremely dry foliage in strong winds and low humidity.
While small compared to the most destructive Western fires, officials described the Minnesota fire’s behavior as “extreme with torching and long-range spotting,” meaning embers were being carried on updrafts and setting secondary fires. Recreation sites were closed in Superior National Forest, as were parts of the Boundary Waters Canoe Area Wilderness, the nation’s most visited wilderness area that sees peak activity in summer.
Firefighters were letting the Boundary Waters fires burn rather than risk becoming trapped in the backcountry with no means of evacuation, said Forest Service spokeswoman Joanna Gilkeson. Air support was being deployed as quickly as possible.
It was the second Boundary Waters closure this summer after thick smoke from Canadian wildfires enveloped much of the state in late July, triggering public health warnings as far south as Minneapolis-St. Paul. Public health experts said the late July smoke haze created “unprecedented” air conditions across the state.
Now the smoke is back.
“It’s really hazy outside. It’s also windy, it’s hot and it’s really dry,” Gilkeson said in a phone interview yesterday from Ely, Minn., a main gateway into the Boundary Waters.
It also was the first round of what could be a fiery summer and fall for the middle of the country as extreme heat and drought make life uncomfortable, and even dangerous, for tens of millions of Americans. Experts say fire conditions like those felt in California are shifting eastward, slowly but surely.
“The frequency of these midcontinent Northern fires is starting to go up because of drying from climate change. But we’re at the very start of that change, whereas California is well ahead of us,” Lee Frelich, director of the University of Minnesota Center for Forest Ecology, said in a telephone interview. “It’s inevitable that the drying will become more prominent here and those dry conditions will progress steadily further east as the years go by.”
Large wildfires are not new to Minnesota. In August 2011, the Pagami Creek Fire, started by a lightning strike, smoldered for days before quickly accelerating across 92,000 acres of the Superior National Forest. The Forest Service faced criticism for what some said was a slow response to that fire. In 2007, an unattended campfire ignited what became a 75,000-acre wildfire in the Ham Lake area of the Superior forest.
Gilkeson said the Greenwood Fire remained “extremely active” despite efforts by federal and state authorities, including Minnesota National Guard troops, to knock the flames down.
“The concern is we have structures in the path of the fire. There are some permanent residents, but quite a few structures are cabins and lake homes that have been in families for generations. It’s emotional for people, and they’re very concerned,” she said.
Scientists are concerned, too, as the great forests of the Great Lakes — concentrated in Minnesota, Wisconsin, Michigan, and the Canadian provinces of Manitoba and Ontario — succumb to climate change in ways both subtle and profound.
Frelich said the increasing size, intensity and frequency of wildfires in the interior forests is a “harbinger” of what’s to come with climate warming.
Forest managers and scientists throughout the region are seeing evidence of a changing landscape, often drier and warmer than historical averages. This is especially true in the shoulder seasons, but also during summer’s peak when prolonged periods of above-average temperatures can zap moisture from soils and plants.
“Basically, there are certain conditions under which these fires cannot be controlled, especially in a boreal-type forest that is of the most flammable vegetation types on the planet,” Frelich said.
Even healthy boreal forests are not immune to fire. Natural fire is integral to maintaining an ecosystem for highly adapted plants and animals. Among other things, wildfires clear forest understory, providing space for birch and aspen saplings that are the preferred diet for northern moose.
But just as wildfire can improve food security for moose, climate change brings another set of stresses to those heat-averse animals, whose population in Minnesota is holding steady at about 3,100 after a steep decline during the early 2010s.
“An increase in moose would be a good thing until the summers get so warm that they start dying of heatstroke,” Frelich said.
Yesterday, however, was about protecting human life and property. State and local officials issued evacuation orders for roughly 75 homes immediately north of the fire zone.
Two primary highways crossing the forest remained closed, heavy firefighting equipment was being deployed and a dedicated incident management team planned to take command this morning. Officials were trying to measure the fire’s size from the air, but were “having some issues with smoke,” Gilkeson said.
