Canadians should expect more extreme weather like the current heat wave baking southern Ontario and Quebec in the future because of climate change, a leading climatology professor says.

"My strong opinion is that these kinds of extremes are something you would expect in a warming world, and expect to happen more frequently," Harry McCaughey, a professor of climatology at Queen's University, told

McCaughey says climate models show that overloading the climate with carbon and water vapor (a byproduct of a warming globe) makes the system much more unstable.

"As you warm the system, you tend to get more swings, more highs and more lows," he said.

New York Times columnist Thomas Friedman has dubbed the phenomenon "global weirding" -- an assessment McCaughey agreed with.

"The climate gets weird in the sense that you have no experience . . . of what might happen," McCaughey said.

McCaughey said politicians need to immediately begin taking steps to address the issue.

"We need to really examine out energy mix, how we create and use energy," he said. "We need to begin decarbonizing the system, removing to the greatest possible extent and greatest rate possible . . . on an emergency basis, the use of carbon loaded fuels.

"Canada is simply not a leader in this area."

A massive ‘rare' heat wave

A massive high-pressure system of hot, humid air has enveloped the Gulf Coast states through Ontario, Quebec, and as of Wednesday afternoon, all the way across to the western part of New Brunswick as well.

"The system that we see today is not inconsistent with what we expect to see in the future if we keep on pushing the climate in a single direction, and that's the worry," McCaughey said.

He added the current system is "relatively rare" due to its extended stay over central Canada.

On Wednesday, temperatures were expected to reach 34 degrees Celsius in Toronto and Montreal and 32 C in Fredericton.

High humidity has it feeling more like in the low 40s in Toronto Wednesday.

Environment Canada expects the current heat wave to break on Friday, when thunderstorms are expected.