From @cnnclimate: Twice as much food as previously estimated is wasted, with people in wealthier countries wasting more, according to a recent study published in the journal PLOS One. Climate experts have identified food waste as one of the top sustainability problems worldwide. "Globally, if food waste could be represented as its own country, it would be the third largest greenhouse gas emitter, behind China and the US," according to the United Nations environment program. The UN estimates annual global food waste at 1.3 billion tons. (: Don Emmert/AFP/Getty Images)