Telegraph: Photographs of emaciated polar bears have gone viral on social media, and raised concerns over the effects of global warming. One, taken by National Geographic photographer Paul Nicklen, shows a dead polar bear lying on a pile of rocks in the Arctic archipelago of Svalbard. Mr Nicklen is trained as a biologist and has worked in the Arctic for decades. He says that on a trip to Svalbard last summer he was unable to locate any live bears, but did find two that appeared to have starved to death....