The continuing increase in temperatures has been seen across the globe, but perhaps nowhere so visually as in the Arctic. As permafrost melts, it's revealing valuable fossils from mammoths and other prehistoric animals, worth tens of thousands of dollars, and often sold to museums. Finding and selling the remains can be a much-needed cash flow in impoverished Arctic villages, like this one in Siberia. But the thawing permafrost doesn't only give up valuable mammoth tusks and skulls: it also exposes mammoth stools to the air, releasing a stink not smelled for millennia. And the stink isn't even the bad part: as microbes in the feces warm up and become active again, the ancient dung releases carbon dioxide and methane, contributing even further to global warming.