A man gathering firewood to sell cuts down mangrove trees in the coastal area of Medan city on Indonesia's Sumatra island on Jan. 31. The country, which has one-quarter of the world's mangroves, is losing them at a rate of 6 percent a year. The coastal forests play important ecological and environmental roles. Suntanta Aditya/AFP/Getty Images hide caption

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Germany plans to take all of its nuclear power plants offline by 2022, which means coal-fired power plants like the Kraftwerk Westfalen, in Hamm, Germany, will be a key component of the country's energy infrastructure. Lars Baron/Getty Images hide caption

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Young corn plants grow next to the Guardian Energy ethanol plant in Janesville, Minn. Five years ago, the U.S. government projected that in 2012, ethanol production would use up 30 percent of the nation's corn supply. Last year, it used 40 percent. Glen Stubbe/MCT/Landov hide caption

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In this undated picture, Mount Everest, the world's tallest mountain at 29,029 feet, stands behind the Khumbu Glacier, one of the longest glaciers in the world. Nepal has more than 2,300 glacial lakes, and experts say at least 20 are in danger of bursting. Subel Bhandari/AFP/Getty Images hide caption

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A clampdown on contamination in growing fields has pushed out wildlife and destroyed habitats. Adam Cole/NPR hide caption

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Carlton Ward Jr., leader of the Florida Wildlife Corridor Expedition, kayaks into the Everglades sunset. Steve Newborn/for NPR hide caption

itoggle caption Steve Newborn/for NPR

Pictured here on April 13, 2011, Barataria Bay — part of Louisiana's Barataria Basin — was one of the hardest hit areas in the aftermath of the Deepwater Horizon oil rig explosion. Today, obvious signs of the spill have faded, but communities are still reeling from its effects. Mario Tama/Getty Images hide caption

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