Yukon’s climate, notoriously cold in Gold Rush days, is transforming

By Yereth Rosen, Alaska Dispatch News - September 28, 2016
Sunset on a tributary of the White River, south of Beaver Creek, Yukon on Sunday, June 28, 2015.
Sunset on a tributary of the White River, south of Beaver Creek, Yukon, in June 2015. (Loren Holmes / Alaska Dispatch News)

In the days of poet Robert Service more than a century ago, Canada’s Yukon territory was almost as notorious for its fierce cold as it was for the powerful gold fever that gripped stampeders who rushed into the Klondike.

“Talk of your cold! through the parka’s fold/ It stabbed like a driven nail,” the Bard of the Yukon wrote in a poem that told the tale of a Gold Rush miner who got warm only when his corpse was cremated.

But by the end of this century, expect the Yukon to feel less like the Arctic and more like the northern Rocky Mountain and prairie regions, according to a new study that examines “cliomes,” the term used to describe localized climates that support distinct habitats.

Of 17 existing Yukon cliomes, seven will probably disappear by 2100, and one new one — favorable to prairie grasslands — will spread from the south, according to the study, published in the peer-reviewed journal Global Ecology and Conservation.

Northern Yukon, where the changes are expected to be most dramatic, will no longer have climate conditions that favor arctic tundra, according to the study. In the mountains of northern and central Yukon, the climate will favor boreal forests instead of alpine tundra now found there. In the southern part of the territory, the climate will become more like that found in the prairies of Saskatchewan and Manitoba.

“It doesn’t mean we’re going to be planting canola soon, but it does mean that we’re going to see a disconnect with the ecosystem and the climate,” said Nancy Fresco of the University of Alaska Fairbanks, a co-author of the study.

A lag occurs between the arrival of a new climate and the spread of new types of vegetation and other features that match the climate and make up an ecosystem, said Fresco, coordinator of UAF’s Scenarios Network for Alaska and Arctic Planning program (SNAP).

The triangle-shaped Canadian territory of the Yukon runs from thick forests of spruce, pine and aspen in its southeast corner to the Arctic Ocean shoreline on the north. It holds Mount Logan, Canada’s tallest peak, vast glacial fields, open plateaus and dry valleys.

Climate change will jumble conditions in those local areas, with some areas taking several shifts to warmer climate types over the coming decades, according to the study.

The new study is an outgrowth of an earlier project that spanned Alaska and neighboring parts of Canada. The project produced an Alaska-Canada report that is posted on the SNAP website. The Yukon section is the first to be in a peer-reviewed paper published in a scientific journal, Fresco said.

It is a rare scientific spotlight for the far northwestern region of Canada, an area often overlooked in global discussions about climate change.

Alaska and its warming climate get wide attention — and even had a high-profile presidential visit in 2015 — but the Yukon and the neighboring Northwest Territories have similar climate conditions, Fresco said. The territories, with their sparse populations and small communities, have government agencies that study climate issues but lack big research institutions that would be the equivalent of UAF.

“They don’t really have that resource,” Fresco said. For that reason, UAF’s SNAP program has established Canadian partners and has done some long-term Canada-specific forecasts, such as an evaluation of the Yukon’s water resources and the Northwest Territories’ Great Bear Lake.

Significant changes in the Yukon have already been measured.

Average temperatures in the territory have increased by 2 degrees Celsius (about 3 ½ degrees Fahrenheit) over the last 50 years, and by 4 degrees Celsius (just over 7 degrees Fahrenheit) in winter, according to Environment Yukon, the territorial government’s environmental agency. Yukon glaciers have lost nearly a quarter of their surface area since 1958, and glacial melt is causing water shortages in some places — including the total disappearance of one river this summer — and flooding in others, according to Environment Yukon.