Climate change not one heat wave but a pattern of extremes: Waterloo scientist

A University of Waterloo climate scientist says the scorching heat wave that set records in Ontario and Quebec over the Canada Day long weekend can't be directly attributed to climate change.

But Blair Feltmate also says that suggesting the two aren't linked would be like arguing that no particular home run can be attributed to steroids when a baseball player on a hitting streak is caught doping.

Feltmate, who is also the head of the Intact Centre on Climate Adaptation, says while one isolated event might be normal, the world and Canada are seeing more extreme weather events — patterns that can be attributed to climate change.

The heat wave, which kept the usual crowds away from Canada Day celebrations on Parliament Hill, marked the highest-ever humidex in the national capital — and is poised to become the longest extended high-humidity and heat event in the city's history.

A 2017 study in the journal Nature Climate Change found that about one-third of the world's population already lives somewhere where the daily temperatures are considered lethal more than 20 days a year.

Even with drastic cuts to greenhouse gas emissions in the next 75 years, that number is still expected to grow to 50 per cent of the population — or 75 per cent, including parts of Ontario and Quebec, if nothing is done at all.