What can we do to protect against another Fort McMurray-like super fire?

The wildfires that swept the Canadian city of Fort McMurry earlier this year are now classified as the biggest natural disaster to ever hit Canada in terms of dollars. Some $6 billion worth of property went up in smoke.

In this era of global climate change, the far north is the fastest warming part of the world, with fires doubling in size over the past 50 years. People are now beginning to rethink how to protect forest communities like Fort McMurray.

“In Canada, our average annual area burned used to be one million hectares per year in the early ’70s. It is now 2 million hectares per year and we believe this is due to human-caused climate change, and in particular the temperature,” says Canadian wildfire expert Mike Flannigan.

“I get asked all the time, why temperature? Well, three reasons: First, the fire season is longer, the warmer we get. In Alberta, our fire season officially started this year on March 1 — it used to be April 1. Second, the warmer it is, the more lightning you get. The more lightning you get, the more fires you get.

"Third, probably the most important: As we warm, the atmosphere's ability to hold moisture increases almost exponentially. What this means is the atmosphere is more effective at sucking the moisture out of the fuel. Projections of the future say we're going to warm, but we’re not going to get that much more precipitation. Bottom-line? Dry air fuels — easier for fires to start to spread.”

Flannigan says there are a few reasons the fire was so devastating. 

“There are three ingredients for a forest fire to occur,” Flannigan says. “How much fuel you have — how dried it is is really important. The second ingredient is ignition — and people and lightning are the two common ignition agents. The third reason is the weather — hot, dry, windy, we call it. So you need all three to come together and that's exactly what happened this spring at Fort McMurray.

"We have lots of fuel in the boreal forest. We had an ignition that's still under investigation. I'm 99 percent sure it's human-caused because of the time of year and the location, the proximity. And we had hot dry windy weather.”

To avoid devastating fires in the future, Flannigan says it’s important to do prevention work. Humans are unable to control weather patterns and lighting, but there are other things we can do. 

“Fire is opportunistic. It likes to find a pathway, it’s looking for a wick,” Flannigan says.

“I think the biggest gains can be made by managing fuels around communities, reducing the amount of fuel, the type of fuel. Conifers are very flammable, so you want to remove conifers around communities. If you have trees, have deciduous trees or have grass, you can have sprinklers. Don't have things like wood shingles on your roof, pine needles in the eave troughs, wood decking, shrubs beside your house, firewood stacked by your house. … There’s guidelines and suggestions for homeowners and for communities to reduce the risk of fire.”

Both Canadian and American fire management agencies have begun to change their thinking about fire management in recent years. After the 1988 Yellowstone fires, many people considered the blazes a complete disaster. Flannigan, however, says fires aren’t always bad. 

“The reality is, it's part of ecology of the forest,” Flannigan says. “Trees in the boreal western United States, they're used to regular stand-replacing, stand-renewing fires. Fire management in the United States and Canada has moved away from the full suppression model. It used to be, you put out all the fires, all the time.

"Now we have something called appropriate response, and when a fire starts, they determine if it's an unwanted or dangerous fire, and if so, they hit hard, they hit fast. However, if a fire occurs in the wilderness, we run fire growth models for the next week or two, and say, 'where will that fire spread?' If it's not spreading towards communities then we say, 'we'll monitor this fire and let Mother Nature do her job.'"

"So this is the new reality — we have to live with fire, coexist with fire because we cannot completely eliminate it. We've tried to eliminate fire and it doesn't work.”

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