Over the years, polar bears have become a symbol both for those who argue that urgent action on global warming is needed and for those who claim that climate change is not happening or, at best, that the issue is overblown. But scientists say during earlier warm periods the bears probably had significant alternative food sources, notably whales, that they do not have today. The researchers needed to be able to determine, as precisely as possible, the periods when sea ice would be gone from a particular region. “The study shows clearly that polar bears are going to do better with less warming,” he added. But others, notably in the southern Beaufort Sea off northeastern Alaska, and in the western Hudson Bay in Canada, have been severely affected by loss of sea ice.

Source: New York Times July 20, 2020 15:01 UTC