‘Zombie fires’ are burning even in the winter amid Canada’s record-setting fire season

NPR’s Ayesha Rascoe talks with Lori Daniels, a forestry expert at the University of British Columbia, about “zombie fires” that continue to burn through the winter in remote areas.


Canada had a record-setting wildfire season in 2023. Over 45 million acres burned, with smoky, dangerous air spreading across North America. And now there’s a new record of sorts – a higher-than-usual number of fires continuing to burn in remote parts of British Columbia through the winter. They’re called zombie fires. For more, we turn to Lori Daniels, a professor of forests and conservation sciences at the University of British Columbia. Welcome to the program.

LORI DANIELS: It’s my pleasure to join you.

RASCOE: What exactly is a zombie fire?

DANIELS: Well, a zombie fire is a fire that we thought maybe was out at the end of the summer but has actually gone underground and is persisting through the winter beneath the snowpack, smoldering away underground, and in the spring will pop back up as an open flame when the temperatures become warm and the ground dries out again and the breeze comes up, facilitating that forest fire.

RASCOE: How is the fire able to continue burning under snow?

DANIELS: Well, this year, we have been in a multiyear drought here in British Columbia. And in the northeast part of the province, we just did not get the rains that we anticipated in the fall that would really saturate the ground and put those fires out. Even under a normal snowpack, you can get these fires where pieces of the fire sit below ground and maybe a piece of wood buried below the ground or these soils that we call organic soils in peat and bogs. Think of the peat moss that people buy and put in your gardens – that’s organic material that’s highly flammable. But below ground, the fire can sit smoldering, generating heat, continuing to combust but not popping up into the surface until it is warm and dry enough in the spring.

RASCOE: Is this all about climate change?

DANIELS: This is a combination of factors. Zombie fires have occurred, you know, throughout history. This year in British Columbia, when we hit December 31, BC Wildfire still had 106 fires on record as no evidence that they were completely out and likely a large number of those having gone below ground and might be fires of concern again next spring. Normally, we would have, you know, maybe a few fires to maybe a couple of dozen fires in that category.

RASCOE: So how likely is it that these zombie fires will become or come back as, you know, raging wildfires in the spring when the temperatures are higher?

DANIELS: Not all of them, but we are anticipating that next spring will also be a warm and dry condition. We’re in an El Nino year, and El Nino’s in the Pacific Northwest region of North America, including British Columbia. El Nino years mean that we end up with warmer winters but lower snowpacks. And when those snowpacks – when it becomes warm in the spring, the snow melts out earlier. The ground begins to dry earlier. And that gives us a longer summer season. Fantastic if we’re on summer holidays – not so good from a fire perspective where we’re already in drought conditions. And those forests and the flammable fuels in them will begin to dry out quickly, giving us a deeper drought and more extreme fire conditions, potentially next summ
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