How climate change is making wildfires worse in normally mild and wet Atlantic Canada

Nova Scotia's record-breaking fires came as a shock in a region known for relatively mild and wet weather. But rather than being an anomaly, they are a sign of things to come for Atlantic Canada, experts say.

That's because of how climate change is disrupting the region's underlying weather patterns, and making it more prone to intense and longer fire seasons.

"People don't normally think of fire in the Maritimes or forest fire being a thing here," said Anthony Taylor, professor of forest management at the University of New Brunswick in Fredericton.  

"But instances like last week hit home the fact that it does occur here, and it can occur here in a big way."

The climate is changing the region in several significant ways — with hotter weather, less predictable rain, and more tropical storms — that overall have scientists forecasting fire-conducive weather patterns could double or triple in Atlantic Canada by 2080.

And while the fires the region will probably never be as large and dramatic as the vast wildfires in the country's western and northern forests, they will nonetheless threaten people and communities — as Halifax residents saw vividly when hundreds of homes in the city's periphery were damaged or destroyed.

"We're going to be living with fire and all this smoke in the air now and for many years to come," said Lynn Johnston, forest fire specialist with the federal government's Canadian Forest Service.

Less predictable rain

Like the rest of the Canada, Atlantic Canada is getting hotter because of human-caused climate change. According to projections, summer temperatures in the Maritime provinces and Newfoundland and Labrador could be 2-4 C above normal by 2050. 

But precipitation — rain and snow — will also change, with impacts on wildfire patterns.

Atlantic Canada is expected to remain wet, and the total amount of rain is expected to rise slightly — but the way it falls will become more uncertain, with a lot of precipitation at some times and dry spells at other times.

"If that precipitation doesn't come regularly and we have these persistent hot, dry and windy spells that stick around for a long time, that's a big problem for fire activity," said Johnston, whose research focuses on climate change and how it is impacting forest fire patterns across Canada.

"Because once that fire starts, if it's hot, dry and windy for a week, two weeks or longer, that's really, really, really good weather for fires to burn."

That could lead to longer fire seasons, she said, and the fires within those longer seasons being more intense and unmanageable.

Eastern forests have some natural resistance

In general, forests in the Atlantic region are less prone to fire than other parts of Canada. That's because they have a mix of tree species — deciduous, which shed their leaves in the fall, and evergreen.

Deciduous trees, like maple, birch and beech, have moist leaves and are generally less likely to go up in flames than evergreen trees with cones and needles. 

By contrast, the vast boreal forest that covers Northern Canada is characterized by mostly evergreen coniferous trees, which are more prone to large fires.

But even deciduous trees will burn under the right conditions — including long dry spells — and climate change is going to make those conditions more common. 

The total area that burns every year in the region is also projected to go up, according to Taylor — about double what's seen now.

And adding fuel to the fire — literally — are tropical storms that are expected to reach the east coast more often and with growing intensity, a reality all too familiar after Hurricane Fiona last September. These storms blow down trees, which can become kindling for fires down the line. 

"Even though we have less forest fire here, if conditions warm as they're projected to do and we do see this more than doubling of area burned, that's significant for a small region, especially in a region where we have a high density of people," he said.

Fires moving closer to people

All the experts point to a key risk factor of fires in Atlantic Canada: how close they happen to where people live.

In the Halifax area, fires in the communities of Hammonds Plains and Tantallon destroyed about 150 homes. Over 16,000 people had to flee the area.

The area burned in Nova Scotia from two major wildfires, including the Halifax-area one, was 24,000 hectares — an unprecedented amount for the province. It pales in comparison to the 3.3 million hectares burned so far across Canada, but it shows how even relatively smaller fires have a big impact in Atlantic Canada.

"The density of people in the Maritimes is quite high, given the geographical area," said Taylor.

"If you have an increase in the fire risk then I think it's going to directly impact people's lives, just because we're not that far removed from the forest."