What the decline of mountain snow cover means for Canada | Canada News Media
Connect with us

News

What the decline of mountain snow cover means for Canada

Published

 on

This winter brought a healthy snowpack to many mountain peaks in North America.

California experienced record snow, at times burying communities and ski hills and in Canada, skiers and snowboarders enjoyed the powder this season, with British Columbia experiencing a flush of late-season snow putting snowpacks right around normal.

But despite this snowy winter in the mountains, climate change is taking its toll on our slopes.

So how is our mountain snow changing, what can we expect going forward, and what does that mean for our water supply?

Global trends in snow

Claudia Notarnicola is a researcher with Eurac, a private research centre based in Italy. She has studied how mountain snowpacks across the globe have changed over the past 40 years.

Notarnicola said that in her research, which examined mountain snow cover between 1982 and 2020, there were wild swings in snow year-to-year, but a clear long-term trend.

Claudia Notarnicola has been studying how mountain snow cover has changed over the past 40 years. (Annelie Bortolotti/Eurac Research)

“There is a general decrease, but the variability is very high,” she said when talking about snow cover of global mountain ranges.

Notarnicola’s research shows a decrease of around 3.6 per cent in yearly snow cover, and an average drop in 15 days for snow cover duration globally.

Though North America showed high variability, with pockets of increased snowfall at lower elevations, the overall picture is dominated by snow cover decline and a delayed start in the season with an earlier spring melt.

“There is a correlation between snow coverage and snow coverage duration, but I’d say the duration seems to be more affected,” she said.

But the decline goes beyond the past 40 years.

Snow in the Canadian Rockies

John Pomeroy, Canada Research Chair in water resources and climate change at the University of Saskatchewan, says the snow-cover period in the Canadian Rockies has declined by anywhere from four to six weeks since the early 1970s.

This decline is in part due to faster snow melts in the spring and warmer falls, but is also affected by lower snowpack levels.

While snowpacks are harder to keep track of accurately as they require in-person surveying, Pomery says that in the regions he has studied, there are noticeable trends, including in the Kananaskis Valley.

Though there is a lot of variation in snow cover year-to-year, our Rocky Mountains are seeing four to six weeks less of snow cover on average since the 70s. (Caitlin Hanson/CBC)

“Our higher elevation snowpacks were holding, and even our middle elevation snowpacks were holding. But at the lowest valley bottom, we do have much less snow than we used to,” he said.

That stability at high elevations is thanks in part to Canada’s colder climate, which is different from what is experienced in the United States or the Alps, according to Pomeroy.

“[There] the higher elevations are affected by climate warming in terms of melting the snow, earlier or causing less snow over the winter, but we haven’t seen that at all in the Canadian Rockies yet.”

And with shorter winters set to continue, Pomeroy says the ripple effects will become more pronounced in Alberta’s mountains.

“We see shorter and shorter snow seasons and less than half of the current snowpack in the valley bottoms going forward, virtually none in some years,” he said.

“In the middle elevations we see a fairly large drop in snowpack dropping to about half, but at the highest elevations there’s a shorter snow season, but the peak snowpack is about the same.”

Implications downstream

Despite more stability on the Canadian Rockies’ highest peaks, our shifts in mountain snow will have an effect on those relying on that water.

Pomeroy says the eastern slopes are critical for water supply for cities, irrigation, hydroelectric power and for the ecosystem.

Going forward Pomeroy says shorter seasons will mean a shift in timing for prairie river flows from the peak in June to late in April or even early May.

Mountain fed rivers like the Athabasca will see a change in when peak flow occurs, and more water stress late in the season as climate change continues. (Caitlin Hanson/CBC)

Those rivers will also face a lot of variability, with higher streamflows in the winter and early spring with lower stream flows without glacier support in the hot and dry summers.

“The snowpack acted as a reliable reservoir to hold water and release it even in the hot dry years and the glacier is very much the same feature,” he said.

“As we lose glaciers and lose some of our low elevation snowpack, we lose the dampening of stream flow that we’ve had and the reliability that it will always peak in the spring and drop off in the summer.”

“We have quite a few decades of very serious problems ahead of us no matter what we do and we’re going to have to manage our waters very sensibly to achieve any kind of water sustainability,” he said.

Pomeroy said that this management can include using water more efficiently and storing water that flushes into the system earlier to use during irrigation later on.


Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled “Our Changing Planet” to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.

 

Source link

Continue Reading

News

End of Manitoba legislature session includes replacement-worker ban, machete rules

Published

 on

WINNIPEG – Manitoba politicians are expected to pass several bills into law before the likely end of legislature session this evening.

The NDP government, with a solid majority of seats, is getting its omnibus budget bill through.

It enacts tax changes outlined in the spring budget, but also includes unrelated items, such as a ban on replacement workers during labour disputes.

The bill would also make it easier for workers to unionize, and would boost rebates for political campaign expenses.

Another bill expected to pass this evening would place new restrictions on the sale of machetes, in an attempt to crack down on crime.

Among the bills that are not expected to pass this session is one making it harder for landlords to raise rents above the inflation rate.

This report by The Canadian Press was first published Nov. 7, 2024

The Canadian Press. All rights reserved.



Source link

Continue Reading

News

Father charged with second-degree murder in infant’s death: police

Published

 on

A Richmond Hill, Ont., man has been charged with second-degree murder in the death of his seven-week-old infant earlier this year.

York Regional Police say they were contacted by the York Children’s Aid Society about a child who had been taken to a hospital in Toronto on Jan. 15.

They say the baby had “significant injuries” that could not be explained by the parents.

The infant died three days later.

Police say the baby’s father, 30, was charged with second-degree murder on Oct. 23.

Anyone with more information on the case is urged to contact investigators.

This report by The Canadian Press was first published Nov. 7, 2024.

The Canadian Press. All rights reserved.



Source link

Continue Reading

News

Ontario fast-tracking several bills with little or no debate

Published

 on

TORONTO – Ontario is pushing through several bills with little or no debate, which the government house leader says is due to a short legislative sitting.

The government has significantly reduced debate and committee time on the proposed law that would force municipalities to seek permission to install bike lanes when they would remove a car lane.

It also passed the fall economic statement that contains legislation to send out $200 cheques to taxpayers with reduced debating time.

The province tabled a bill Wednesday afternoon that would extend the per-vote subsidy program, which funnels money to political parties, until 2027.

That bill passed third reading Thursday morning with no debate and is awaiting royal assent.

Government House Leader Steve Clark did not answer a question about whether the province is speeding up passage of the bills in order to have an election in the spring, which Premier Doug Ford has not ruled out.

This report by The Canadian Press was first published Nov. 7, 2024.

The Canadian Press. All rights reserved.



Source link

Continue Reading

Trending

Exit mobile version