Fausta Ortiz, 38, Pastoruri's glacier guardian, stands guard while carrying her daughter Lisoyun, 2, in Huaraz, Peru, Thursday, Dec. 4, 2014. According to Alejo Cochachin, coordinator of the glaciology unit, the Pastoruri glacier retreated 576 meters between 1980 and 2014. Peru's glaciers have lost more one-fifth of their mass in just three decades, and the 70 percent Peru’s 30 million people who inhabit the country’s Pacific coastal desert, depend on glacial runoff for hydropower and to irrigate crops, meaning their electricity and long-term food security could also be in peril. Higher alpine temperatures are killing off plant and animal species in cloud forests and scientists predict Pacific fisheries will suffer. (AP Photo/Rodrigo Abd) (The Associated Press)
LIMA, Peru – The U.N.'s environment agency says the cost to poor countries of adjusting to ever-hotter temperatures will be twice or even three times higher than previously thought — and that assumes a best-case scenario in which greenhouse gas emissions are dramatically reduced.