‘Zombie fires’ threatening Canada in winter – 02/18/2024 – Environment

Even in the depths of Canada’s winter, embers from last year’s record wildfire season linger.

So-called “zombie fires” are burning even in winter — they are embers that continue to live in the ground under thick layers of snow. And they are growing at an unprecedented rate, raising fears about what the coming summer might bring.

People driving on the highway that passes through the city of Fort Nelson, British Columbia, in winter can easily see — and smell — the clouds of white smoke flowing from the ground around them.

Sonja Leverkus, a firefighter and scientist who lives in the small northeastern town of the province, remembers driving through a snowstorm in November, but the snow didn’t look white.

Instead, she said, it was blue-gray because of the smoke in the air.

“I’ve never seen a snowstorm that smelled like smoke,” said Leverkus, who has lived in the area for more than 15 years.

Smoke clouds were still visible in February, she added, even on extremely cold days when temperatures dropped to -40°C.

Zombie fires

Fort Nelson’s smoke is the result of “zombie fires” — also called “winter fires.”

They are flameless embers that burn slowly below the surface and are kept alive thanks to an organic soil called peat, common in North American boreal forests, and thick layers of snow that insulate them from the cold.

Such fires are not uncommon. Over the past 10 years, British Columbia has seen, on average, five or six that continued to burn through the cold months, experts say.

But in January of this year, the province recorded an unprecedented spike of 106 “active zombie fires,” raising concern among scientists about what these fires could mean for the upcoming wildfire season.

Most typically extinguish on their own before spring, but 91 are still burning in the province, according to local administration data.

Those that are not extinguished by March will pose a major risk when the snow melts and they are exposed to the air. Scientists have linked them to the early start of wildfire seasons.

The neighboring province of Alberta has also seen an increase in these winter fires, with 57 outbreaks in early February – almost 10 times more than the five-year average.

“It’s very alarming to see this continued combustion throughout the winter, especially after Canada’s record wildfire season last year,” says Jennifer Baltzer, a biology professor at Wilfrid Laurier University.

More than 18 million hectares (44 million acres) of land have been burned by wildfires in Canada in 2023 – an area roughly the size of Cambodia – far exceeding the country’s 10-year average.

The season was one of the deadliest in recent history, with several firefighters dying in the line of duty.

Thousands of people were forced to flee their homes and the effect was felt far beyond Canada’s borders when smoke covered large parts of the US in June.

This calamitous wildfire season is one reason why British Columbia is now seeing such a high number of zombie fires, says Mike Flannigan, a professor and fire management expert at Thompson Rivers University in Canada.

Most of them are fires that couldn’t be fully put out until last fall simply due to a lack of resources, he said.

By the end of the year, authorities had recorded a total of more than 2,200 wildfires in the province.

Another reason, Professor Flannigan said, is the extreme drought the province has faced over the past two years.

In February, most of the region was under medium to extreme drought levels, according to the drought map.

Just like the “zombie fires,” the drought has also been noticeable, says Leverkus.

When she was in the woods last summer, she said she noticed that a creek that used to flow freely is now “just puddles.”

These dry conditions persisted through the winter. The province saw so little snow that a ski resort in the South Cariboo region was forced to close its doors in early January for the rest of the season.

Consequences of climate change

“Zombie fires” were once rare, but scientists say they have become more common in recent years due to global warming.

For now, the “zombie fires” are only being monitored by authorities, says Forrest Tower, spokesman for the province’s authorities.

He said many of them can’t be put out manually because most of the province’s firefighting force is off duty during the off-season. They do not yet pose a risk, he said.

But the main concern is that the fires could reignite if the region continues to get very little snow or rain in the spring.

If that happens, he said the province’s seasonal wildfire team could immediately spring into action in March or April.

Flannigan says it’s too early to predict exactly what the next fire season will look like, but what the province has seen so far “is quite unusual.”

And with it being an El Niño year, which portends hot, dry conditions for western Canada, Flannigan says everything points to “a very active spring.”