What can we learn from North America’s increasing fires and heatwaves?

As the northern hemisphere swelters through summer, the Canadian province of British Columbia is fighting nearly 200 wildfires.

The fires are the result of a heatwave that broke records across northwestern USA and southwestern Canada last week. Extreme heatwaves like this are going to become more frequent, and more intense, as human-induced climate change progresses.

The immediate cause of the current heatwave, and subsequent fires, is a ‘heat dome’ – a meteorological phenomenon that involves the presence of hot air through all layers of the atmosphere, preventing cool sea breezes and cloud cover.

According to the US National Oceanic and Atmospheric Administration, temperature records, which are normally beaten by small increments, tumbled by huge amounts across the region. For instance, Quillayute in the US recorded a maximum of 43°C (110°F), six degrees above its previous high of 37°C (99 °F). Lytton, in Canada, broke a nationwide temperature record when it reached 46°C (116°F). A fire later destroyed much of the town, killing two people.

Forest fires are a yearly phenomenon in North America, but the current fires have burned a much larger area than average for this time of year, and more fires are expected as the northern hemisphere summer progresses.

Australia shares firefighting resources and personnel with the US and Canada, although the pandemic has limited this, and there are growing concerns that the expansion of the fire season in each hemisphere will require resources deployed on both sides of the equator at the same time.

Something that can be shared much more easily is data: over the past decade, research in both Australia and North America has become useful in predicting the speed and spread of fires.

“While the environments are quite different, there are many lessons in fire science that can be learnt between Australia and Canada, from fire behaviour to warnings,” says Richard Thornton, CEO of the Bushfire and Natural Hazards CRC.

There are, of course, major differences between fires in different environments. Fuel load, for instance, is one of the fundamental predictors of fire spread, meaning that the types of trees in different regions play a big part in how large fires behave.

“As we continue to learn from the Black Summer fires of 2019–20 here, and share the knowledge gained with other researchers from countries like Canada, Australia too will be able to learn from the current Canadian fires,” says Thornton.

“Research collaboration is vital, both in sharing knowledge from afar, but also through research exchanges, with Australian scientists spending time with colleagues in Canada, and Canadian researchers working in Australia.”

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Read more:

• The climate crisis Australia our children could inherit
• Bushfire experts clash over logging impacts
• From small dry things bushfires grow
• What fuelled Australia’s “Black Summer” fires?