Rising temperatures and deeper droughts are at least partially responsible for a wildfire season that is roughly two months longer today than it was in the 1970s.Stephen Brashear/Getty Images
On a Sunday in late August, the sky over Portland turns a deep, impenetrable grey. The air smells overwhelmingly of smoke. Health officials urge those with respiratory ailments to stay inside.
Not far from the city, a complex network of wildfires burns. All along the northwest United States, the better part of 900,000 acres is ablaze.
It has been a particularly brutal wildfire season in the United States this year – part of a wider trend that has seen increasingly longer, costlier and deadlier seasons over the past few decades.
But behind the images of raging forestland flames that have dominated the news in the northwest these past few months, there lies a more complex, expensive problem – one that pits the realities of climate change against the increasing urbanization of America's wildest land.
By most experts' accounts, seasons of longer and bigger wildfires are here to stay. Rising temperatures and deeper droughts are at least partially responsible for a wildfire season that is roughly two months longer today than it was in the 1970s.
"There's a bunch of stuff we can't do anything about, like the heat buildup from the last 30 years," says Ray Rasker, executive director of Headwaters Economics, an independent research group that studies land-management decisions in the western United States.
"It's a very big shift – we need to learn to live with fire, rather than fighting every big fire."
Ironically, another reason current-day forest fires have become so big, costly and deadly is because Americans have become almost too good at fighting them.
For years, areas such as the Ponderosa Pine forests of the Colorado plateau would regularly burn – in the process, thinning out the smaller growth between the large trees. But increasingly aggressive firefighting efforts have cut down on such fires. The result is a massive buildup of fuel – small trees and shrubs that act as a conduit for wildfires to move over much larger parcels of land.
"The U.S. Forest Service has about 400 million acres of forested land in that kind of condition, in need of treatment," says Michael Medler, a former wildfire-fighter and chair of the department of environmental studies at Western Washington University. "Your treatment options are cutting with chainsaws or using fire. But 400 million acres is unimaginably big."
Indeed, 400 million acres is an area roughly the size of Alaska – a state where, so far this season, about five million acres have burned.
"We can either manage fires or let them get bigger and hotter – we need a lot more fire in the back country."
But in many regions, that's easier said than done. Since 1990, some 60 per cent of new homes in the U.S. have been built in areas described as the Wildland Urban Interface – in other words, areas where development presses right up against untamed land.
As a result, fires that once did little more than thin out forests now pose a potential risk to property. In the 1980s, fewer than 700 structures, on average, were burned each year. By 2012, that number hovered around 5,000. During the same period, virtually every other measure of fire severity – from the cost of fighting wildfires to the number of firefighter deaths – has also skyrocketed.
It is, in many ways, a self-perpetuating cycle. Increased home-building near forested areas means more pressure on authorities to aggressively combat fires. That, in turn, leads to a buildup of small trees and other fuel that would be thinned out in normally occurring blazes – so when the wildfires do strike, they feed on the fuel and burn hotter and longer than they otherwise would.
As with many climate-change-related problems, this one pits economics against environment. Roughly 90 per cent of wildfire firefighting costs are related to the defence of homes – so as more and more homes are built on at-risk land, firefighters are forced to dedicate more and more resources to containing fires that would otherwise serve a beneficial purpose.
As such, researchers and government agencies are focusing their efforts on trying to convince at-risk communities to prepare for – rather than simply react to – wildfires.
Dr. Rasker and his colleagues are currently working with the Department of the Interior, the White House and other government arms to build a federally funded grant program designed to help communities become more fire resilient. Much of the program is focused on changes in development priorities. For example, Dr. Rasker says, communities could fast-track the application process for home developers who agree to build with more fire-resistant materials, clear the brush from the land and undertake other preventative measures.
"We have a $2.2-billion [U.S.] fire budget in this country," says Dr. Rasker. "With 1 per cent of that, we can work with 100 communities around the West on better land-use planning."
He estimates that, of the roughly 70,000 communities throughout the country at risk of wildfire-related crises, only about 2 per cent are engaged in thorough fire-prevention planning efforts.
In the meantime, forest-adjacent development continues, largely unfettered. And the amount of money the federal government spends every year on defending those homes from wildfire has tripled over the past three decades.
Dr. Medler, who recently spoke to a U.S. Senate panel on the need for significant fire-policy reform, casts an eye toward the logical conclusion of those trends.
"I honestly don't think we've seen a really bad fire season in the U.S. yet," he says. "What keeps me awake at night is the image of 20,000 houses in San Diego being taken out by a fire that goes from being a wildland fire to an urban fire going from house to house to house.
"I just don't think we've done what we can to try to prevent that sort of thing from happening."