Science, Tech & Environment

Climate change is fueling a spike in wildfires across the Americas

burning trees.jpg

A tree on fire is seen as wildfires blaze near the Paranoa neighborhood in Brasilia July 29, 2015. Drought, high temperatures and low humidity in areas have caused wildfires to start in several places in Brasilia, according to officials.

Credit:

Ueslei Marcelino/Reuters

North America is on fire. Nearly five million acres in Alaska have burned in 2015, and the wildfires are on pace to become the largest ever in Alaska’s history. More wildfires are spreading across Canada, California, Oregon and Washington. Climate change, scientists warn, will only continue to make the wildfires worse.

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This story is based on a radio interview. Listen to the full interview.

Nicky Sundt, a climate policy analyst at the World Wildlife Fund, used to work as a smokejumper in the 1980s. He has seen wildfires in North America get continually worse over the last three decades.

“The average annual number of large fires in Alaska has doubled, and there's also been a big increase in the size of those fires,” Sundt said. “The fire behavior is unlike what we used to see three decades ago. The fuels are drier and it's just burning hotter, it’s burning cleaner and burning down into the soil more than it used to.”

Sundt points to climate change for the increase in wild fires. Warmer temperatures are drying out forests and grasslands more quickly, turning them into easy fuel for fires started by humans, or by lightning strikes.

Climate change not only aggravates wildfires, but scientists say that the millions of burning acres are in turn worsening climate change.

A study released by researchers this year found that two-thirds of carbon loss in California occurred on the six percent of the state burned by wildfire. And many say, if the wildfires continue as they are predicted to do, the carbon loss will only get worse. Sometime by the year 2030, according to the National Climate Assessment, US forests will not be absorbing carbon, as much as releasing it back into the atmosphere — a trend researchers think might happen in large part because of wildfires.

Wildfires are doing more than releasing carbon into the atmosphere. They are burning through tundra, and accelerating permafrost melt.

“Permafrost contains vast quantities of carbon that can be emitted then, not only as carbon dioxide but also as methane, which is a very, very, powerful greenhouse gas. So you can get into a situation where the fires are accelerating the loss of carbon from these landscapes and actually feeding climate change even further,” Sundt says.

Wildfires are doing more than filling the atmosphere with greenhouse gases. They’re also emitting large quantities of smoke. This year smoke from Canadian and Alaskan fires caused authorities to issue air quality alerts across much of the American Midwest as well as Colorado and Washington. The soot, which is being deposited across Nova Scotia, Greenland and the North Atlantic, can fall on ice or snow. Once the snow is blackened by soot, it absorbs sunlight, speeding up the melting process.

In order to temper the vicious cycle of worsening climate change and wildfires, Sundt suggests focusing on reducing carbon emissions into the atmosphere.

Beyond that, Sundt says, there is a need to prepare for an increase in large wildfires that will become more and more difficult to manage.

“If we continue releasing carbon dioxide into the atmosphere and if climate change continues unabated,” Sundt said, “We cannot possibly cope with the consequences whether it has to do with wildfires or whether it has to do with increasing flooding or any of the other many consequences of climate change that we're seeing emerging now.

This story first aired as an interview on PRI's Living on Earth.