evidence: A new study suggests that polar bears could face extinction as climate change drives sea ice loss, according to a new study published Monday in the journal Nature Climate Change, showing the potentially dramatic consequences of warming global temperatures. All but a few of the 19 subpopulations of polar bears scattered across the coldest reaches of the globe could be wiped out by 2100 as the warming climate continues to erode sea ice, according to the study. [...] Global Warming Is Driving Polar Bears Toward Extinction, Researchers Say (New York Times)