Seattle Times: These days the news is full of beautiful – and wrenching – images of polar bears, often swimming in unending open water, or standing on tiny ice floes. Although polar bears swim readily, ice is the habitat to which they are best suited – where they hunt the seals that are their prey. And the ice is shrinking. Even those only vaguely familiar with polar bears know they are heading into troubled times. Scientists now know enough about climate change to model future sea-ice conditions. …