Global Courant
Canada is experiencing its worst-ever start to the wildfire season, with fires ravaging much of the country and creating dangerous smoky conditions across the continent and beyond.
After reaching New York earlier this week, it blanketed Washington, D.C., in an unhealthy haze on Thursday, forcing many residents to stay indoors.
Here’s what we know about the wildfires, their trajectory and climate change.
What Caused the Canadian Wildfires?
In Atlantic Canada, little snow fell this winter, followed by an exceptionally dry spring.
Only 4 inches (120 mm) of rain fell in Nova Scotia’s capital, Halifax, between March and May, according to meteorologist Michael Carter of The Weather Network.
A scorching heat wave in late May pushed temperatures in Halifax to 33C (91.4F) on Thursday, about 10 degrees Celsius above normal for this time of year.
But most wildfires are believed to have been accidentally started by human activity.
Ellen Whitman, a research scientist with the Canadian Forest Service, said there is also speculation that trees cut down during Hurricane Fiona, which hit Atlantic Canada in September 2022, or killed by an infestation of forest pests, may be supplying more fuel than usual for forest fires. but that theory requires further investigation.
The many fires in Quebec have been caused by lightning.
While the focus has been on the smoke in eastern North America, fires continue to rage in western Canada.
This view from yesterday in British Columbia. pic.twitter.com/3jUXxYPpwu
— CIRA (@CIRA_CSU) June 8, 2023
Are the wildfires under control?
Not yet.
As of Friday, there were 427 active fires and 232 were out of control, according to the Canadian Interagency Forest Fire Center.
In the West Coast province of British Columbia, authorities reported 81 active wildfires — 28 got out of hand — while in the province of Alberta, authorities reported 72 active wildfires.
Quebec, on the east side of the country, has 128 active fires.
The fires have spread over about 4.3 million hectares (10.6 million acres), about 15 times the annual average over the past decade.
Where are the Canadian wildfires?
The wildfires began in British Columbia and Alberta in late April, displacing more than 30,000 people and halting oil and gas production at their peak.
They have now opened new fronts and spread to the eastern provinces of Nova Scotia, Quebec and Ontario.
Canada is currently receiving international aid to fight the wildfires. Aid has come from the United States, South Africa, Australia and New Zealand. In Europe, France, Portugal and Spain also sent more than 280 firefighters to Canada.
How do the fires affect air quality?
On Thursday, authorities in Washington, D.C. issued a “Code Purple” air quality alert, warning of “very unhealthy air conditions for the entire public, not just those with respiratory illnesses.”
New York again had the worst air quality Thursday morning, with an unhealthy air quality index of 185, according to an IQAir website.
Readings over 100 are classified as “unhealthy,” and those over 300 are “dangerous.”
On Wednesday, authorities in Canada said air quality in Ottawa was among the worst.
Experts have noted that sharp clouds of smoke and ash could continue to affect the daily lives of people in the US and Canada for days to come.
Why does the smoke reach so far?
Strong winds high in the atmosphere can carry smoke for long distances, and it’s common for large, violent fires to create unhealthy conditions hundreds of miles away from where forests burn.
In Canada, air circulates counterclockwise around a low-pressure system near Nova Scotia. That sends air south over the fires in Quebec. There, the sky picks up smoke and then turns east over New York State, carrying smoke toward the East Coast.
The smoke has now also been detected thousands of kilometers away in Norway, the Scandinavian Climate and Environmental Research Institute NILU reported on Friday.
“Very weak” concentrations of smoke particles have been detected since Monday, particularly at the Birkenes Observatory in southern Norway, researcher Nikolaos Evangeliou told AFP news agency.
New York City residents wear protective masks as the city experienced its worst air quality on record due to a cloud of ash and smoke from the Canadian wildfires (Shannon Stapleton/Reuters)
What are the prospects?
Warm, dry conditions are expected to continue across Canada for months to come, though occasional rain and cooler temperatures are expected to bring relief in the short term.
The Weather Network’s long-term forecast expects temperatures in Nova Scotia to be slightly warmer than usual for the rest of the summer.
What role does climate change play?
Whitman of the Canadian Forest Service, said it’s difficult to determine the effect of climate change on a single fire season. Atlantic Canada has been much hotter than normal and scientists expect temperatures in the region to continue to rise for years to come.
For coastal areas, climate change is expected to bring more rainfall, which should reduce the risk of wildfires, but a warmer atmosphere is more efficient at extracting moisture from the soil, a factor that increases fire risk.
Widespread spring fires across Canada are also uncommon, with research showing that fire seasons in North America are getting longer.
According to Joel Thornton, professor and chair of the Department of Atmospheric Sciences at the University of Washington, a warming planet will produce hotter and longer heat waves, causing bigger, smokier fires.
I have never seen such a vertical wall of smoke near Fox Creek, Alberta on a Sunday.
And the strangest thing about this moment was that I couldn’t smell any smoke. #ABfire #ABfires pic.twitter.com/I6vmJvUay4
— Kyle Brittain (@KyleBrittainWX) May 17, 2023
