This browser does not support the video element.

Health and Science

How humans have made wildfires worse

Zoeann Murphy/The Washington Post

Burning since late July, Northern California’s Mendocino Complex and Carr Fire are among the biggest blazes in state history. As of Aug. 14, the two fires combined have torched more than half a million acres and destroyed more than 1,000 homes. Eight people have died in the blazes, including four firefighters and two small children.

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

CalFire continues to battle these fires and 13 other major blazes in the state. According to the U.S. Forest Service, there were 55 large uncontained fires in the United States burning in the third week of August.

Stuart W. Palley for The Washington Post

For the western United States — and most of the world — deadly and destructive blazes like the Carr Fire are the “new normal,” researchers say.

According to the National Interagency Fire Center, wildfires today burn roughly twice as long as they did in 1990.

The average number of acres burned per fire has doubled.

Meanwhile, federal spending on fire suppression ballooned from a little less than $400 million to nearly $3 billion.

This is partly a problem of our own making, scientists say. It’s the product of forestry practices and warming from human-caused climate change.

And because more and more people are moving into fire-prone landscapes, the consequences will probably get worse.

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

Many forests in the western United States are “fire adapted” said Scott Stephens, a fire ecologist at the University of California at Berkeley. Natural wildfires every 5, 10 or 20 years help clear debris from the forest floor and make room for stronger, healthier trees.

Archaeological and historical records show that Native Americans honed their environment using controlled burns for hundreds of years.

But beginning in the late 19th century, the U.S. government established a policy of fire suppression. Wildfires were seen as the “moral and mortal enemy of forests,” according to one Joint Fire Science Program report — they damaged agricultural land and destroyed valuable timber.

As as result, fuel for fires — brush, leaf litter, dead trees — has been building up for a century. When a spark does light, the resulting blaze is more destructive.

This is what happened in the mixed conifer forest that constitutes some of the area burned in the Carr Fire.

Because of warmer weather, forests are drier and prone to burning earlier in the year. Droughts also prolong fire season by delaying the wintertime rain and snow that can help put fires out.

A 2016 study in the Proceedings of the National Academy of Sciences found that climate change accounts for more than 50 percent of the increase in fuel aridity in western U.S. forests.

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

Stuart W. Palley for The Washington Post

The high cost and devastating toll of recent wildfires is also tied to the large numbers of people living in fire-prone landscapes. Nearly half of the West’s population lives in what’s known as the “wildland-urban interface,” where human development brushes up against forest, grassland and other natural ecosystems.

This presents firefighters, land managers and local community leaders with a dire choice: risk lives to battle the blaze or let people’s homes burn.

So how do we fight these devastating fires?

We don’t.

So how do we fight these devastating fires?

We don’t.

“There aren’t enough people in the U.S. Army to stop a fire like that,” Stephens said of the Carr Fire.

All firefighters can do is defend individual structures, and attempt to “contain” the blaze. This involves digging trenches and bulldozing trees around the circumference of a fire to deprive it of fuel and stop it from spreading. On Aug. 14, the Carr Fire was 65 percent contained, according to CalFire, which means that firefighters have built a fire break around less than half of the blaze.

This browser does not support the video element.

Zoeann Murphy/The Washington Post

This browser does not support the video element.

Zoeann Murphy/The Washington Post

This browser does not support the video element.

Zoeann Murphy/The Washington Post

Wildfires are as unstoppable as hurricanes, Stephens said — and much like hurricanes, increasingly inevitable as the climate changes. “But you could do a lot more when you’re getting ready for fire to inevitably occur,” he said. By building with fire-safe materials, establishing buffer zones between ecosystems and communities, and better caring for forests before fire season starts, some of the destructiveness of fires could be mitigated, Stephens said.

“I don’t want people to think this is all climate change and we’re just spectators,” he said. “We can do a lot better with the way people live in these communities.”