NASA images show Qori Kalis (above), a glacier that is part of the world’s largest tropical ice cap, on a plateau 18,670 ft. (5,691 m) high in the Andes Mountains of Peru. In 1978, the glacier was still expanding. But not anymore. By 2011, it had retreated far enough to leave a lake 86 acres (35 hectares) in area and 200 ft. (60 m) deep. Human-influenced climate change has also contributed to the retreat of Muir and Riggs Glaciers (next pages), in Alaska. Courtesy of NASA

How a War on Science Could Hurt the U.S.-and Its Citizens

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