The Arctic is warming more quickly than the rest of the world, and the ice is melting. The ice flows are where polar bears hunt seal, which is the main part of their diet.If there is no ice the bears have no food. Even if the bears don't starve to death they become too weak and malnourished to reproduce.
The Canadian governement needs to ensure that oil and gas exploration in the Arctic is limited.
But in the end, just as it took the whole world to put the polar bear into danger, it will take the whole world to pull it back.