As planet warms, ferocious snowfalls could increase
Forecasters say a warming global climate could actually cause some parts of Canada to see colder conditions, including heavy snowfalls like the one that hit parts of the Maritimes this week.
There's a direct relationship between the temperature of the atmosphere and how much water it can hold, said Judah Cohen, a research affiliate at the Massachusetts Institute of Technology, who works as a director of seasonal forecasting at Verisk Atmospheric and Environmental Research.
"It's like a sponge. If the atmosphere is very warm, it could hold a lot of moisture," he said. "You put all the water in the sponge. And then as you slowly lower the temperatures, it's like squeezing the sponge, and so all the water comes out of it," he said.
Beginning Friday, the sponge got squeezed as a stalled low-pressure system off Nova Scotia's coast dumped up to 150 centimetres of snow in parts of Cape Breton, prompting local states of emergency and a call from the province for federal help in digging out.
About 20 or 30 years ago, Cohen said, the consensus in the scientific community was that a warming world would result in less snow. But now it is believed climate change could lead to more intense snow and rain, he said.
John Clague, a professor of geosciences at Simon Fraser University in Burnaby, B.C., said ocean temperatures in the North Atlantic have increased in recent years, allowing temperate air masses along Canada's East Coast to hold more water vapour. When this moisture-laden warm air comes into contact with arctic air, "crazy" amounts of snow fall, he said.
"In my view, it's another example of extreme weather that may have the fingerprint of climate change on it," he said of the recent Nova Scotia storm.
"No single extreme weather event can be attributed to climate warming, but we have been seeing far more of these extreme events around the world ... It's not inconsistent with climate change."
Clague said the climate in North America is largely controlled by the jet stream. He described the jet stream as a continuous fast-moving band of air that sits high in the atmosphere. It separates polar air in the north from temperate air in the south.
Although wobbly, the jet stream, he said, is usually fairly fixed within a range of latitudes in the Northern Hemisphere.
"But over the past decade, the jet stream has become more snakey and unpredictable -- wandering over a larger range of latitudes," Clague added.
"During this winter storm, the jet stream has moved south and allowed arctic air to move over the Maritimes, impacting populated areas like Nova Scotia and Prince Edward Island."
Cohen agreed, adding that the reason parts of Nova Scotia got more than a metre of snow was the changing jet stream.
An atmospheric ridge caused by the jet stream twisted itself over the continent in an inverted horseshoe shape, making its impact felt on both the East and West Coasts, he said. The stalling of the jet stream caused the air ridge that hit the high pressure to be blocked from moving east, bringing days of rain in California and snow in Nova Scotia.
"It's like a traffic jam in the atmosphere, and weather systems get stuck," Cohen said. "If you're stuck in a high pressure ridge, you are more likely to get a heat wave. Or if you're maybe stuck in a cold trough, you are more likely to get heavy rain events and flooding. And as in the case of Nova Scotia, you can get more snow."
This report by The Canadian Press was first published Feb. 6, 2024.
For more Nova Scotia news visit our dedicated provincial page.
CTVNews.ca Top Stories
Police arrest Toronto woman in connection with three recent homicides
Police have arrested a Toronto woman in connection with three recent homicides and investigators say that they believe two of the victims may have been 'randomly targeted.'
NDP house leader says House dysfunction will be a factor in future confidence votes
NDP House leader Peter Julian says there's more his party wants to do in Parliament before the next election, but if the current dysfunction continues it will become a factor in how they vote on a confidence measure.
Canadian family stuck in Lebanon anxiously awaits flight options amid Israeli strikes
A Canadian man who is trapped in Lebanon with his family says they are anxiously waiting for seats on a flight out of the country, as a barrage of Israeli airstrikes continues.
Youth pleads guilty to manslaughter in death of P.E.I. teen Tyson MacDonald
A teen charged with the murder of another teen on Prince Edward Island last year has pleaded guilty to a lesser charge of manslaughter.
BREAKING Jury begins deliberations in Jacob Hoggard's sexual assault trial
The jury tasked with determining if Canadian musician Jacob Hoggard sexually assaulted a young woman in northeastern Ontario eight years ago began deliberating Friday after nearly two weeks of testimony that saw the singer and his accuser give starkly different accounts of what happened.
BREAKING Here's what the jury didn't hear in Jacob Hoggard's sexual assault trial
A northeastern Ontario jury has started deliberating in Canadian musician Jacob Hoggard's sexual assault trial, we can now tell you what they weren't allowed to hear.
Yazidi woman captured by ISIS rescued in Gaza after more than a decade in captivity
A 21-year-old Yazidi woman has been rescued from Gaza where she had been held captive by Hamas for years after being trafficked by ISIS.
Scientists looked at images from space to see how fast Antarctica is turning green. Here's what they found
Parts of icy Antarctica are turning green with plant life at an alarming rate as the region is gripped by extreme heat events, according to new research, sparking concerns about the changing landscape on this vast continent.
Suspect in shooting of Toronto cop was out on bail
A 21-year-old man who was charged with attempted murder in the shooting of a Toronto police officer this week was out on bail at the time of the alleged offence, court documents obtained by CTV News Toronto show.