…we are repeatedly warned, if the planet continues to overheat at the present rate, within four decades our biggest carnivore will be extinct, starved to death as its natural hunting grounds disappear. "Come up and see them while you still can," is the gist of their depressing refrain. snip When outsiders question whether anyone would be so cynical, they are reminded of that now-famous photograph of a polar bear which appears to be teetering precariously on an Arctic ice-floe, melting faster than ice-cream, in the depths of winter. For a while, it became a powerful symbol of the perils of...