Canadian Press: Canada has conceded that a polar bear treaty signed more than 35 years ago is pushing the government to take action against climate change. Talks this week in Norway on the 1973 conservation agreement have ended with all five countries that signed it concurring that melting sea ice is now the biggest single threat to the future survival of the bears. “The parties agreed that long-term conservation of polar bears depends on the successful mitigation of climate change,” says the signed …