So how will climate change affect Toronto?

Narcity spoke with Kent Moore, professor of atmospheric physics at the University of Toronto Mississauga (UTM), who shared with us what Toronto can likely expect in the years to come and how climate change will affect the city itself.

What kind of extreme weather events can Toronto expect?

“Toronto has warmed on average about a degree and a half, maybe two degrees, over the past 30 years. That means our summers are hotter and our winters are warmer, too,” said Moore.

“We have seen a lot of very heavy downpours over the past few summers which are causing flooding,” he added. “This is in line with what we would expect to see with warming, because as the atmosphere warms it may contain more water vapor.”

Toronto experienced a hot and humid summer in 2021, with the city recently reaching highs of over 40C with Humidex and closing in on mugosity records previously set in the 1950s. According to the Government of Canada, Toronto has experienced a average temperature of 20.3 C in August 1990. This August, average temperatures around 24.0 C.

But, Moore explained, that doesn’t just mean sweatier residents – it means more damaged infrastructure.

How could climate change affect Toronto?

“The basic problem is that our infrastructure just wasn’t designed for the climate we are experiencing today,” Moore said.

He cited neighborhoods above subway tracks and the Don Valley Parkway as a few examples of areas of the city that will face as flooding becomes “more common” in Toronto.

“Anytime you have water flowing on the surface and you don’t have the infrastructure to support those water flows, you’re going to have flooding,” Moore continued.

“It happens even downtown,” he said, referring to a 2013 viral video of a flooded Ferrari in the Lower Simcoe Underpass.

FERRARI UNDER WATER! # Storm IN TORONTO FLOOD !!! @ReneLaVice

“We have paved a lot of riverbeds in the Toronto area,” said Moore. “So if you live in a little depression where there was a river running through it, then water is going to pool in that area.”

“You can mitigate these things by building some sort of levee or levee, but it’s a huge expense.”

Moore noted that the amount of heavy rain in recent years has also had an impact on Toronto’s basements.

“Over the last few years, there have been a few of these very, very severe rain events where people’s basements have been flooded,” Moore said. “So yeah, I think the basement apartments could be less livable.”

How can Toronto prepare for climate change?

Asphalt in the city is a problem for both extreme heat and flooding, Moore noted.

He explained that asphalt absorbs more heat than grass and soil, and only moves water elsewhere rather than capturing it and letting it seep into the ground.

This results in a “heat island” effect, which makes the air warmer and increases water runoff, which is more damaging to urban infrastructure such as sewers.

The expert said the city was changing to adapt to these dangers, stressing two underground holding tanks in the beaches, which trap sewage and stormwater overflows, preventing them from flowing into Lake Ontario.

Moore said Torontonians should make small changes to help – like switching to public transit or paving their driveway with interlocking bricks instead of asphalt, so water can seep into the ground.

“It will not only help Toronto, but the whole world as well. It is a global problem, but we can help solve it locally,” he concluded.