Freezing rain to become the new norm in winter storms for southern Ontario, report projects

The recent winter weather in southwestern Ontario has some people pointing to climate change as the cause, but a climate modeler with University of Waterloo says there are too many variables on a regional scale to come to any conclusions.

Chris Fletcher says research and data clearly show global temperatures are warming.

But, he says, there is always more uncertainty when making predictions about climate on a smaller scale.

"We have a noisy system. We can have swings of temperature from one day to the next of 25 or 30 degrees without any problem at all," he explains.

"And that's just natural variability. It's very hard when that kind of variability is happening to be able to pick up the signal of climate change."

Marie-Eve Giguere, a meteorologist with Environment and Climate Change Canada, told CBC's The Morning Edition with Craig Norris it's "too hard" to tie recent weather specifically to climate change.

Fletcher agrees, adding that it's a challenge to isolate individual weather events or seasons and say they are a direct result of climate change.

Looking forward

A 2015 report on climate change, which Fletcher participated in, predicted that Waterloo region will experience a four to five degree change in temperature over the next 100 years.

Fletcher said the report also points to research that predicts southern Ontario could see a 40 per cent increase in instances of freezing rain and ice during the winter, due to a combination of warming temperatures and increased precipitation.

There is even evidence that snow tourism and hockey rinks are less sustainable that they used to be, he said.

But for now, Fletcher says it's difficult to say if the changing weather people have experienced in their lifetime is reflective of natural or man-made changes in climate.

"I think where we're on a bit of safer ground is looking forward, looking further into the future," he said.

"What's going to happen is that signal of climate change is going to become much stronger."