New records have been set for the largest areas burnt, but is that a good measure of fire severity? Considering the devastating impacts - apparent in tandem with record-setting heatwaves, smoke, and pyroCybs - is a better metric. Canada Wildfire Science Director Mike Flannigan wraps up the 2021 fire season and what that means for 2022.
Dry tinder, large fires
This fire season got off to an early start, with large fires in Manitoba in May. British Columbia, Saskatchewan, Manitoba, and Ontario all had substantial amounts of area burnt, which isn’t necessarily the most significant variable (more on that later). Spring started dry for the southern areas of Canada from northwestern Ontario to British Columbia. Then fires started in Manitoba, followed by active fires in northwestern Ontario and Saskatchewan.
In 2021, Manitoba had over 1 million hectares that burned, while both Saskatchewan and BC were not that far off from 1 million hectares each as well. In BC, the top three years in terms of area burned have occurred in the last 5 years (2018, 2017, and 2021, respectively) for the period 1950 – 2021. Meanwhile, Ontario had the largest area burnt on record since 1959. In Canada, around 4.2 million ha have burned, and this is well above normal.
New records have been set for the largest area burnt - but is that a good measure of fire severity?
Is the area burned the best metric of fire season severity? Probably not. In our Canadian forests, wildfire is a natural process that may be helpful in some circumstances, so having more “good fire” on the landscape is not a negative. What metric should we use instead of area burned?
Fire Impacts might be a more useful metric and would include direct fire impacts such as loss of life, homes & structures lost, evacuations required, watersheds & species at risk, and economic impact. Even though the numbers are not finalized for 2021, we can guess that the 2021 fire season had significant impacts across all these metrics.
Blocking ridges causing devastation
Towards the end of June, a historic heatwave hit the Pacific Northwest and spread throughout Alberta and Saskatchewan. The all-time high temperature for Canada (45°C) was shattered several times and by many degrees, with temperatures nearing 50°C in Lytton, British Columbia, at the end of June. Tragically, the heat was followed by a devastating fire that took the lives of two people and destroyed much of the town of Lytton. This heatwave was a result of a large blocking ridge in the upper atmosphere. Fire researchers have known for decades that these blocking ridges are associated with significant fire activity.
Wildland fire smoke was also a significant issue during the 2021 fire season. Many regions of Canada experienced weeks of extremely poor air quality due to smoke — and the more we find out about smoke, the more we will find out how bad it is for us. Additionally, recent studies have found that wildland fire smoke makes us more susceptible to COVID-19.
Self-generative and active
On June 30, 2021, a massive pyroCb near Kamloops BC generated thousands of lightning strikes and started tens of fires up to 40 km downwind, the most lightning strikes and fire starts I have ever seen from one pyroCb. There have been over 50 pyroCb events in North America this year, the most on record, but the dataset on pyroCbs is limited.
A few days later in July, there were active fires from YK & BC all the way through to Quebec. It is extremely rare to see active fires over such a large longitudinal band. As I write this story in early October, they are very active.
Still, even more remarkable is that these fires are burning through the night, and nights are long in October. We may be seeing more and more night-time burning as our climate changes.
What will the 2022 fire season bring?
Who knows, but if we have another hot and dry year, we will see more wildland fire and more smoke. Fire is a multi-faceted issue that will need multi-prong approaches - there is no cure for wildfire.
We all have to learn to live with wildfire.