Polar bears, ice and climate change

WWF January 6, 2016 0

In October 2015 I had the pleasure of accompanying guests on Natural Habitat Adventures’ Classic Polar Bear Adventure in Canada. I work on climate change adaptation for WWF, and a large part of my work is focused on how climate change is impacting species, and how we can help them adapt. Polar bears are the poster child for these impacts, and justifiably so. To date, global warming has been most pronounced in the Arctic, and this trend is projected to continue.

Polar bears’ dependence on their sea ice habitat is what makes them so vulnerable to a changing climate. They rely almost entirely on the sea ice environment for traveling, hunting, mating, resting, and in some areas, maternal dens. In particular, they depend heavily on sea ice-dependent prey, such as ringed and bearded seals.

Sparring polar bears in Churchill, Canada, waiting for the ice to freeze over as the winter approaches. © WWF-US/Nikhil Advani

Sparring polar bears in Churchill, Canada, waiting for the ice to freeze over as the winter approaches. © WWF-US/Nikhil Advani

The population in Churchill is one of the few that spends the summer on land. Most bears follow the retreating summer sea ice, and thus remain on the sea ice year round. However, bears are now spending increasing amounts of time on land, as the extent of summer sea ice declines, and the ice melts earlier and freezes later than it used to. Polar bear viewing season in Churchill is in October and November. It was eye opening to see male bears lining up along the shore, clearly anxious for the ice to freeze over which would give them access to blubber-rich prey. It’s an even longer wait for the females with cubs, who don’t take to the ice until the males are gone. For most of the bears that spend the summer on land, it’s been a long few months of fasting using up their stored fat reserves.

Some estimates project that the Arctic could be completely devoid of summer sea ice by mid-century. A truly scary thought for the persistence of this iconic Arctic species. All hope isn’t lost though. The just-concluded COP 21 climate talks in Paris have hopefully put us on a path to reducing our greenhouse gas emissions, and initiatives like WWF’s “Last Ice Areas”, which identifies sites that are projected to retain sea ice farther into the future than other areas, might be our best hope of helping this species adapt to an ever-changing world.

To learn more about WWF’s work on wildlife and climate change, visit https://www.worldwildlife.org/wildlife-and-climate

About the author: Nikhil Advani is a scientist on the climate adaptation team at WWF. Learn more about his work here: https://www.worldwildlife.org/experts/nikhil-advani 

Leave A Response »