Climate change boosts number of frost-free days in Sudbury: report

A report headed to Greater Sudbury’s planning committee Monday says climate change is leading to a significant increase in the number of frost-free days in the area. (File)

A report headed to Greater Sudbury, Ont.’s planning committee Monday says climate change is leading to a significant increase in the number of frost-free days in the area.

In turn, that’s increasing the risk of severe wildland fires.

“In the Sudbury region, the average frost-free season has increased from 134 days (1976–2005) to approximately 154 days,” the report said.

“Projections suggest this will further increase to 165 days under low-carbon emission scenarios and up to 181 days under high emission scenarios by 2051–2080, potentially extending the wildland fire season by as much as 47 days.”

Annual temperatures

As average annual temperatures increase, so too do the intensity of wildland fires, the report said.

“Wildland fires are fueled by dry vegetation, including grasses, brush and trees,” the report said.

“Increased temperature dries out vegetation more quickly and more thoroughly.”

In addition, the fires are caused primarily by humans or by lightning strikes. Warmer temperatures lead to “the development of more storms capable of producing lightning, the ignition source of more than half of Canada’s wildland fires.”

“Dry heat creates more fuel, while wind spreads wildland fires and makes them more difficult to extinguish. Warmer temperatures also cause earlier snowmelt and delay the first autumn frost, effectively lengthening the wildland fire season,” the report says.

In Canada as a whole, the number of wildland fires decreased from about 9,000 a year in the early 1980s to about 5,000 in the mid-2020s. However, the intensity of the fires increased dramatically.

“Annual averages have risen from about 1 million hectares in the early 1980s to roughly five million hectares in the mid-2020s,” the report said.

“The 2023 wildland fire season was the most severe on record, with 17,347,637 hectares burned across the country.”

Reducing the risks

What that means for Sudbury is that when approving new development, measures must be taken to reduce the risks from wildland fires.

“The combination of risk assessment tools and environmentally appropriate mitigation measures identified by the Ontario Ministry of Natural Resources to be incorporated into the design, construction and/or modification of buildings, structures, properties and/or communities to reduce the risk to public safety, infrastructure and property from wildland fire,” according to the Provincial Policy Statement.

With the growing number of days that are frost-free, so too is the area in the city where wildland fires are a risk.

The city is introducing what it calls Schedule 6B –Wildland Fire Hazard. It’s a document that outlines where the fire risk is highest in the city and will require developers to “demonstrate that wildland fire risks have been mitigated in accordance with provincial standards.”

Read the full report here.