Within the span of a year, Manitoba went from having one of its driest summers in decades to having one of its worst floods on record.
“Everybody who lives on the Prairies for any length of time knows that we have lots of swings, but this is a pretty crazy one,” said Danny Blair, co-director of the Prairie Climate Centre and a climatologist at the University of Winnipeg.
Several climate experts told CBC that while they can’t say definitively that recent weather events are a result of human-driven climate change, they agree it may be a sign of things to come — and a reminder that people need to be prepared for more extreme weather in the future.
Last summer Manitoba set a record for the driest July since 1873; it was the 42nd driest summer in 146 years of records. The winter of 2020-21 was the fifth driest on record.
Fast forward to spring 2022, and while March this year was drier than normal, April was the second wettest in 151 years, with four times the normal amount of precipitation.
“Does that mean that climate change is here in a really big way this year?” Blair said to CBC Up to Speed host Marjorie Dowhos earlier this week.
“No, that’s not the way it works, but it’s symptomatic. It’s indicative of what we should expect more often in the future, and that we should prepare for.”
Blair said the cold and wet winter and spring Manitobans experienced is also an effect of La Niña — a weather pattern that happens every three to five years. La Niña years are often associated with cold and wet winters and springs, followed by hot dry summers, Blair said.
“Which may be a blessing because we need things to dry out for our farmers, and for our basements and for our communities, so we may actually see yet another flip-flop in our weather in the coming weeks,” he said.
Variability is a normal part of Prairie climate, but the swings could become even more dramatic, Blair said.
“We need to make sure that we are ready for, in the years ahead, even wilder swings in the weather,” he said.
“And that includes our frequently flooded communities. Floods are not going away with climate change; they may even become worse.”
While it’s hard to link Manitoba’s recent weather directly to climate change, Blair said Manitobans should be preparing themselves to be more resilient to extreme weather events, like making investments in infrastructure to protect against floods and droughts, and by cutting down on fossil fuel consumption.
Nathan Gillett, a researcher with Environment and Climate Change Canada, also said Manitoba’s recent weather can’t be directly linked to human-caused climate change — because not enough studies have been done with the current data — but it is consistent with warming trends seen around the world.
The Intergovernmental Panel on Climate Change (IPCC) released a report in March on the impacts, adaptation and vulnerability humans face with rising temperatures.
The report’s authors said they had “high confidence” that unless countries step up their efforts to cut greenhouse gas emissions, the planet will on average be 2.4 C to 3.5 C warmer by the end of the century — which experts say is sure to cause severe impacts for much of the world’s population.
What does this mean for the Prairies?
“In terms of the long-term trends, more drought in the summer,” Gillett said.
But at the same time, we’ll also feel the effects of climate change in Prairie downpours.
“The heaviest rainfall events are predicted to get more intense, globally and in Canada,” Gillett said.
While there are natural factors that contribute to climate change, like volcanic activity, there are several ways human activity contributes as well, said Ronald Stewart, a professor of atmospheric science at the University of Manitoba.
“We’ve had a really dramatic increase in greenhouse gases, as you know, but we’ve also changed the land’s surface an enormous amount. We’ve dammed rivers … we’ve put a lot of dust particles into the atmosphere, which weren’t there before, so it isn’t just greenhouse gases. There’s a lot of other factors which actually all come together,” he said.
The recent weather swings in the province may be a good reminder about the effects, Stewart said.
“It’s not that these variations in general have not happened before, but the expectation is, unfortunately, as our climate warms, the large-scale circulation patterns of the atmosphere start to be more conducive to them happening more often,” he said.
The weather over the past year reflects those expected changes.
“I think it’s really interesting if people in Manitoba realize, ‘My gosh, that isn’t just the heatwave going on in India or the heat dome over B.C., that’s the flooding we are experiencing now.’ I mean, that does wake people up.”
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