This article is part of The Climate Exchange, an interactive, digital hub where The Globe answers your most pressing questions about climate change
The polar regions are some of the most important areas on the planet when it comes to understanding climate change, says Philippe Archambault, scientific director of ArcticNet, a network of research centres dedicated to studying the impacts of climate and socio-economic change in the Canadian North. That’s because the ice-covered surfaces of polar regions have traditionally acted as areas that reflect the sun back to itself like a mirror.
A bald eagle (Haliaeetus leucocephalus) perched in a group of trees at sunset near Churchill, Manitoba. Aug 19th, 2024Shane Gross/The Globe and Mail
“A good example I say to the general public is … if you have the sun in your face, that’s quite warm. If I put a mirror between you and the sun, you’re in the shade and the light will hit the mirror and go back. It’s not going to be as warm on your face,” Prof. Archambault says.
But as the planet warms and ice in the polar regions diminishes – summer sea ice in the Canadian Arctic has declined by up to 20 per cent each decade since 1968, while winter sea ice decreased by eight per cent in the same timeframe, according to data from the federal government – both land and water absorb more heat.
The warming of the polar regions is also causing change to its ecosystem – both by introducing new species, which move north as the climate warms, and by harming existing ones, who rely on the regions’ ability to reflect light and heat. Once we lose a species, it’s nearly impossible to get it back. Prof. Archambault likens the shrinking ecosystem in the polar regions to a Jenga tower. Losing a single piece could cause a catastrophic effect, and sometimes it’s hard to predict just what those effects could be.
Sea ice on the Hudson Bay near Churchill, Manitoba is breaking up and melting in the late spring, June 22, 2024.Shane Gross/The Globe and Mail
One example Prof. Archambault uses is marine sponges found in tropical regions. Microbes in these sponges have antiviral properties and are sometimes used to treat conditions such as herpes simplex virus. But marine heat waves have caused some of those sponges to die off, which could lead to a deficit in treatments for certain conditions.
Arctic terns swoop at a polar bear, trying in vain to scare him away from their nests, while smoke from distant forest fires fill the air near Churchill, Manitoba. July 27, 2024Shane Gross/The Globe and Mail
Canada’s polar regions are also home to several endangered species, including polar bears, narwhals and arctic foxes, all of which are seeing their ecosystem slowly destroyed. “We can cool our homes or heat them depending on the weather,” says Prof. Archambault. “It’s not perfect, but humans can adapt. One thing it’s impossible to adapt to is when we lose a species.”