Yukonomist: Visiting the ‘Big Smoke’ gets literal

Yukonomist Keith Halliday

Yukoners obliged to travel to Toronto often jokingly call it the Big Smoke.

There’s no joking now. Last week, Canadian wildfire smoke swept down over Toronto, Boston and New York. The air quality index for New York made Delhi look as pristine as Kluane Park.

These East Coast cities are just the latest to get to know extreme summer smoke events. Back in 2021, record wildfires spread dense smoke over San Francisco and Vancouver. Wildfires in Siberia set new records, with smoke reaching Canada, Greenland and even — for the first time ever — the North Pole.

Here in the Yukon, we’ve always been used to wildfires. Who doesn’t have a story of being stuck coming back from a canoe trip as fire closed a highway?

But they seem to be getting worse.

This brings up climate change, and the nasty feedback loop wildfires play in that phenomenon. Warmer climates tend to have hotter, drier spells of weather as well as more lightning in some places. And when the forest burns, it releases huge amounts of carbon dioxide into the atmosphere. The heat can melt permafrost, releasing carbon from formerly frozen muskeg. Black carbon floats into the sky onto Greenland glaciers, accelerating their melting. All of this, in turn, makes climate change worse. Which causes even more wildfires.

The carbon emissions are big. Scientists estimate that Canada’s wildfires released 270 megatonnes of carbon dioxide in 2021. That’s more than Canada’s heavy industry and massive oil and gas sector combined.

It is depressing to walk downtown to save burning a litre of gas and emitting 2.3 kilograms of carbon dioxide, only to read a news story talking about wildfires releasing 117 billion times more carbon dioxide than you just saved.

Not everyone is convinced that climate change caused this year’s fires. Despite temperatures being on a warming trend since 1980, the Canadian National Fire Database shows a gradually declining trend in the number of fires over that time. Even the famous 2021 fires burned a third fewer hectares than fires in 1981, 1989, 1994 and 1995.

However, there are a host of scientific papers indicating that a warmer climate does increase the chance of big wildfires.

For example, Sarah Kew of the Royal Netherlands Meteorological Institute studied the Siberian fires of 2021. She is an expert in “attribution,” the science of linking climate change to real-world extreme weather events.

She summed up her Siberian findings like this: “The analysis shows that climate change increased the chances of the prolonged heat by a factor of at least 600. This is actually among the strongest results of any attribution study conducted so far.”

You might be wondering how temperature increases of a few degrees or less can result in an alarming 600-times increase in the chances of wildfire-inducing hot spells.

This requires a minor adventure in statistics (skip to the next paragraph to avoid it). As shown in the attached chart from the Intergovernmental Panel on Climate Change, the probability of an extreme event like a wildfire is usually distributed in the classic bell curve. The “Previous Climate” curve has relatively little area in the extreme zone on the right. Then comes the “New Climate.” This curve is shifted to the right by higher temperatures, and also stretched out since hotter climates are more volatile. The result is that the area under the curve in the extreme zone is now much, much larger.

Six hundred times larger in the case of Kew’s Siberian study.

My take is we can be pretty confident climate change is contributing to more severe wildfire seasons. Given humanity’s struggles to get global carbon emissions under control, we should plan on getting used to lots of wildfires in the coming years.

Some have also been saying that this reinforces the need to cut carbon emissions in the Yukon.

This argument is shakier. Canada is only about 1.5 per cent of global carbon emissions. The Yukon produces about 1/1000 of Canada’s emissions, or about 0.0015 per cent of global emissions. We could eliminate all fossil fuel use in the Yukon tomorrow and it would not make a noticeable difference in our wildfire risk.

Which isn’t to say we should stop trying to cut emissions. It is important to do our part. But we should recognize that humanity’s response to climate change will be decided in Washington, Beijing, Delhi and Brussels. Prepare yourself for more wildfires.

So what should we do about it?

First is the risk of wildfire to your property. It’s good our governments are collaborating on the big firebreak south of Whitehorse. You should attend the next Wildfire Awareness Society risk seminar in your neighbourhood. If you haven’t looked into how to de-risk your house in town or your cabin, you should.

Second is emergency preparedness. Keep your vehicle gassed up. You don’t want to end up like our unfortunate fellow citizens in Fort McMurray whose vehicles ran out of fuel during the evacuation from their wildfire. Register with Whitehorse Alert, a government emergency messaging system. Visit getprepared.gc.ca to learn the basics and get a list of emergency kit items for your home.

Third is preparing for smoke. The Yukon spruce tree may be a thing of soulful beauty, but its smoke is surprisingly toxic. Those tiny PM2.5 particles get through paper masks, into your lungs and even into your bloodstream. The way public health professionals talk about wood smoke is downright scary.

The Environmental Protection Agency says these small particles “can also trigger heart attacks, stroke, irregular heart rhythms and heart failure, especially in people who are already at risk for these conditions.”

You may want to buy some quality air filters for your home. Some recommend preparing a smoke haven room with well sealed doors and windows where you and your air filters can hang out and watch Netflix when it gets bad. Even moderate exercise outside during peak smoke events can introduce unhealthy amounts of particles into your bloodstream.

The wildfire smoke even has economic impacts. How will tourism to the Yukon be affected if Outsiders start reading about bucket-list visits being ruined by a week of dangerous dense smoke?

All in all, it is grim news. But no one promised that climate change would be fun.

Keith Halliday is a Yukon economist, author of the Aurore of the Yukon youth adventure novels and co-host of the Klondike Gold Rush History podcast. He won the 2022 Canadian Community Newspaper Award for Outstanding Columnist.