COPENHAGEN—The Altiplano, or high plain, of Bolivia and Peru is getting a new climate. In the past 60 years temperatures have risen, rainfall patterns have changed and soils have begun to dry out even further. As a result, farmers move their crops further up the mountainsides, like endangered species seeking refuge at cooler elevations. Floods and frosts remain the biggest threats but when the entire water system of your area changes, how do you adapt? That is the question residents from the Andes to the Himalayas are asking as the climate changes. Water streams off the Pastoruri Glacier in Peru year-round now, even in July, which is the middle of their winter in the Southern Hemisphere. Some call it an “ice blanket” now, rather than a glacier, thanks to its steady retreat. And much like their Incan ancestors, the residents must build weirs to hold some of the water and save it for their daily lives. Local farmers have also seized control of hydroelectric dams in the region, due to concerns that power producers, such as U.S.-based Duke Energy, might be holding back water needed for their crops. “The farmers felt shortages,” says John Furlow, a climate change specialist at USAID who is attending the United Nations’ climate summit here. “There’s a realization of impacts getting ahead of where the science is.” At the same time, local residents rely on the governments of Peru or Bolivia for protection from avalanches and floods kicked off by newly formed lakes of glacial meltwater or thawing permafrost. “There’s a fair amount of mistrust of the government and a reliance on it to protect people,” Furlow adds. …

Climate change is ridding the world’s tropical mountain ranges of ice