As parts of the country not normally affected by wildfires have been blanketed in smoke in recent months, experts are turning to centuries-old practice as one way to deal with the increasingly violent wildfires.
At the root of the problem, experts say, is a long-standing policy of avoiding fires: keep fires out of the forest.
Beginning in the late 1800s, for nearly a century, firefighting was America’s national policy, putting out fires as soon as they started. While this has successfully reduced the number of burned forests, over time it has led to the accumulation of flammable dead trees and shrubs on the forest floor.
Sean Parks, PhD, is a research ecologist at the US Forest Service Fire Science Laboratory in Missoula, Montana, where they study the behavior of fire in the forest. He says the buildup, also known as fuel, leads to larger, hotter fires.
“Now the fires we are seeing are killing all or most of the trees,” Parks said.
CBS News traveled to Montana as part of our Spot on climate coverage to find out why fires burn so much harder and their impact gets so much stronger.
It wasn’t always like that.
In the Bitterroot National Forest in Montana, Parks leads us to trees covered in fire. Cross-sectioning a stump, Parks shows how trees can bear the scars of long-standing fires set off every 10 to 30 years by the Bitterroot Salish tribe who lived there.
Yet these trees survived. You can see curls in the tree that show where the tree was damaged and started growing back around that scar.
These scars, studies show, are evidence that Native Americans successfully controlled wildfires by regularly lighting small fires to reduce fuel buildup.
After the United States removed the tribe from the land and began the practice of eliminating fire from the forest, many trees did not see a fire for a century or more.
In fact, the tree has no fire scars for 100 years during the firefighting policy. According to Parks, fuel was relentlessly accumulating around him in those years, fueling future fires that burn hotter and deadlier today.
These larger fires eventually killed the centuries-old tree, Parkes said.
“Many of these forests are no longer equipped to survive the inevitable fire,” Parks said.
Parks says climate change is exacerbating this problem.
“There is definitely a link between more fires and climate change,” Parks said. “Now the fuel is drier due to climate change. And the drier the fuel, the hotter the fire burns, and the more difficult it is to put out.”
Making good fires to prevent bad fires
The Salish and Kootenai Confederate Tribes of Montana are leading the way in bringing prescribed fire back to the landscape.
“It reduces the amount of fuel that’s here right now that wouldn’t be here naturally,” said Darrell Claremont, who is in charge of fuel load management on the reservation’s forests.
To build such a fire, ideal conditions are needed: moderate humidity, low temperature and light wind.
In June, the Salish and Kootenai Confederate tribes were making final preparations for the scheduled burning and invited us to come with them. However, the burning had to be canceled after an unexpected downpour.
Clairmont says ideal combustion conditions are getting harder and harder to achieve.
“We’re used to burning a couple of thousand acres a year, and we’ve probably got maybe 300 acres this year,” he said.
Reducing recording windows is a problem. A study in the International Journal of Wildland Fire focusing on the southeastern United States found that “even meeting the basic fire criteria (as defined today) will become increasingly difficult over time” as the climate changes.
In California, for example, the state wants to burn a million acres a year by 2025. But last year only 110,000 acres were burned.
See the impact of fires on the forest
CBS News also followed environmental researcher Kim Davis of the Fire Lab in Montana to see badly burned areas and understand why some forests are recovering from fires while others are struggling.
Twenty-three years ago, a complex valley fire devastated the Bitterroot forest in Montana at Rye Creek. Today, traces of destruction remain: dead tree trunks dot the hillsides. There are few signs of recovery. Davis says this is because when all the trees die, there are no seeds left to regenerate.
“Where we are right now is very far from living trees that survived the fire,” Davis said.
Much of this area has been planted with saplings, but many of these saplings are dying.
Davis says that unlike mature trees, which can adapt to warmer, drier conditions, today’s climate doesn’t allow seedlings to take root in areas that are warmer than they were 50 years ago.
“When you go out into some of these areas, it is very clear that we are definitely already seeing changes due to climate change,” Davis said.
The US Forest Service estimates that 4 million acres – the size of Connecticut – are potentially in need of reforestation.
But there are also bright spots.
Nearby, Davis points to another part of the forest that is being restored. This is the place where the fire of the Valley Complex has swept through, but burned less intensely. As a result, some mature trees survived. They now provide seed and shade, allowing the seedlings to successfully regenerate.
Protecting mature trees from the effects of extreme fires is critical to spurring reforestation and new growth, Davis said.
“I like to see young trees growing. Yes, it’s nice to come to places where trees are growing again,” she said.