Vanishing cold: Climate change projections for northern communities

Canada’s northernmost communities need to prepare for a future that includes dramatic reductions in the number of days when the thermometer will fall below -25 C, suggests a new municipal-level analysis of climate projections.

The Local News Data Hub at Ryerson University compared temperature projections for the period 1951-80 with the period 2051-80 using data from ClimateData.ca, a national data initiative bringing together scientists from university, government and private-sector organizations.

The results for 30 cities and towns show that sweltering summer heat above 30 C will be more common in cities such as Montreal, Toronto, Regina and Saskatoon. And in more northern communities, there will be fewer days when temperatures drop below zero, with deep-freeze temperatures colder than -25 C also occurring less frequently. 

“One thing is clear: Northern parts of Canada are warming many folds faster than the global average, as well as the average across the country,” said Caroline Lee, a senior research associate with the Canadian Institute for Climate Choices. 

“Not only are (northern communities) facing greater hazards, they have less of an ability to deal with those impacts,” Lee said. “The infrastructure there isn’t as robust. You don’t have as many resources, financial resources, or human resources to manage those impacts.” 

For Iqaluit, the projections show that winters in the period 1951-80 used to have an average of three months (94 days) of days colder than -25 C. That is expected to fall to 25 to 63 days per year on average by 2051-80. 

Other famously cold cities such as Yellowknife, Dawson City in the Yukon, and Churchill, Man., which used to experience just over an annual average of 80 days of extreme cold per year, could see that fall by as much as half by 2051-80. For Dawson City, that means 44 to 58 days per year on average when it will be below -25 C. Churchill can expect 34 to 59 extreme cold days. Yellowknife will experience 44 to 62 such days. 

Whitehorse will lose at least a month of days when temperatures drop below 0 C. Residents living in the Yukon capital, who could expect an annual average of 232 frost days back in 1951-80, will see 177 to 202 such days per year in the future. Hot summer days with temperatures above 30 C, meanwhile, will happen more often: Instead of just one day on average per summer, there will be two to 11 days by 2051-2080. 

The Data Hub analysis is based on what climate scientists call a moderate emissions scenario. The scenario is more ambitious than global attempts at reducing emissions to date, but also more pessimistic than the net-zero emissions targets that Canada and other countries worldwide pledged to reach in the 2015 Paris Agreement. 

The projections from the federally funded ClimateData.ca portal are based on 24 different climate models. Comparing 30-year averages ensures that what is described reflects the overall climate and not the more variable experience of weather. The 2051-80 projections are presented as a range to capture both the lower (10th percentile) and higher end (90th percentile) of the models’ outcomes.

With the closing of the United Nations Climate Change Conference, known as COP26, in Glasgow, Scotland, many leaders face increasing pressures in their countries to embrace deeper cuts to greenhouse gas emissions and other measures to slow global warming. Prior to the summit, a United Nations report warned that the planet is currently headed for a temperature rise of 2.7 C by the end of the century that will “lead to catastrophic changes in the Earth’s climate.”

Experts say the prospect of fewer cold days is no reason to rejoice. 

Warmer temperatures will have a major impact on ecosystems and people’s livelihoods in the north, said Chris Burns, a geography professor at Carleton University. Changing ice conditions, for instance, will make travel on rivers unpredictable.

“There are people who live a traditional lifestyle, like Indigenous people, who might be accustomed to using the rivers as part of their daily life in the wintertime,” Burns said. “And then all of a sudden, that season gets cut short by a couple of months, and even in the cold winter-time, it becomes much less safe.”

In the winter of 2017, he noted, Yukon residents were not able to use the ice bridge across the Yukon River that connects Dawson City to West Dawson because temperatures were too warm for the river to freeze up sufficiently, forcing residents to make a 12-kilometre detour to get across.

Burns said that an increase in rainfall in the future will increase the risk of flooding because water can’t penetrate frozen ground. If the surface of the ground becomes heavy with water and makes the soil at the top of permafrost more buoyant, there could be more landslides.

“Both the flooding and the landslides tend to be things for which there is very little warning,” said Burns.

Brian Horton, manager of climate change research at the YukonU Research Centre, said there is already evidence of thawing permafrost: “That can sever a highway, it can cause long-term damage to buildings and really gradual damage, or really sudden damage,” he said. 

More extreme precipitation will also be a major concern in places such as Whitehorse where low-lying areas can quickly flood, Horton added. “(And) if there is an increase in these extreme rainfalls, and lightning, that can cause fires that could become a big concern for both Whitehorse and for many communities all around Central Yukon,” he said.

University of Winnipeg geography associate professor Nora Casson said that individuals can help change the course of history by voting and also by pressuring local, provincial and federal officials to support community efforts to mitigate and adapt to climate change.

“The impacts of climate change across Canada are really regionally different, so adaptation solutions need to be done in consultation with local governments, with Indigenous governments,” she said. “None of the solutions are going to work without buy-in from the community.”

This story has been updated to reflect Brian Horton’s current title. He is the manager of climate change research at the YukonU Research Centre.

This story was produced by the Local News Data Hub, a project of the Local News Research Project at X (also known as Ryerson) University’s School of Journalism. The Canadian Press is an operational partner of the initiative. Detailed information on the data and methodology can be found here.