A leading Canadian scientist says Canada is on the front line of climate change, and researchers are studying once-in-a-century weather events to predict what can be expected in the future.

Francis Zwiers is director of the Pacific Climate Impacts Consortium at University of Victoria. He is speaking across the country, including in Halifax on Saturday, about climate change and whether extreme events are more frequent and intense than in the past.

"We talk about different kinds of events, we talk about things that typically cause large impacts and things that lie at the very edges of our experience," he said.

In particular, weather events only experienced every 50 or 100 years, or never before, he said.

"We want to know if this is part of an ongoing phenomenon so we can plan for it."

One weather event he has studied extensively is the Calgary flood of 2013. It was the biggest financial loss as a result of weather in Canadian history, costing $5.7 billion in damages.

Dr. Francis Zwiers

Francis Zwiers, the director of the Pacific Climate Impacts Consortium at University of Victoria, is speaking across the country about climate change. (www.uwaterloo.ca)

"If you look at precipitation that was received in southern Alberta during that period of time, we come to the cautious conclusion that the amount of precipitation was increased as a result of us humans having increased the amount of greenhouse gas in the atmosphere," Zwiers told CBC Radio's Information Morning.

Using that information, Zwiers said scientists can look forward and predict what weather can be expected. That study is called event attribution and Zwiers said they've been developing the science for about a decade now.

"It is primarily rear-view mirror kind of stuff, you know the big crash on the highway, then we ask why it occurred," he said.

Using their climate models to look into the future, scientists can calculate how the amount of greenhouse gas in the atmosphere might change between now and 2100.

"We ask our climate models whether or not intense temperature events are going to happen more frequently, what's going to happen with really cold events, what's going to happen to precipitation events," he said.

'Incredulous' there are still deniers

Zwiers said he's "incredulous" there are still climate change deniers.

"Evidence has been gathering for a couple of decades now that it really is us that is gradually warming the climate system and that is having impacts across the spectrum of the kinds of things we experience," he said.

The numbers are getting higher, especially when it comes to the temperature of the planet, but Zwiers said the impact in your own experience may be more difficult to detect.

"Looking across the globe the answer is yes, looking in your own backyard, there's nine chances out of 10 you won't notice it there because the day to day variability in your backyard is simply so large," he said. "But it is happening."

Zwiers is speaking at 1:30 p.m. on Saturday at Paul O'Regan Hall at the Halifax Central Library.