Agence France-Presse: Global warming has been rough on polar bears, but for Colorado’s marmots it has meant more food and more sex, according to a unusual study released on Wednesday. Longer summers — and less time spent burning up stored fat during hibernation — have given the large burrowing rodents an evolutionary leg up, said the research, published in Nature. Not only has climate change made individual specimens heavier and healthier, it has led to a marmot baby boom as …