An animal's ranking on the food chain depends on where its meals place on the ladder. That puts plants on the bottom (they make all their food), polar bears on top and people somewhere between pigs and anchovies. Lisa Brown for NPR hide caption

itoggle caption Lisa Brown for NPR

Saltwater wetlands that include marshes and shoals on Virginia's Atlantic coast. U.S. coastal wetlands losses were 25 percent greater from 2004-2009, according to a recent federal study. U.S. Fish and Wildlife Service hide caption

itoggle caption U.S. Fish and Wildlife Service

The Chinese border town of Suifenhe is a port of entry for almost all of the hardwood coming from the Russian Far East. Russia is the world's largest exporter of timber, but illegal logging is a growing problem. Courtesty of EIA hide caption

itoggle caption Courtesty of EIA

Former President Bill Clinton hugs House Minority Leader Nancy Pelosi of California as another Democrat, Sen. Barbara Boxer of California, looks on at Wednesday's ceremony naming the Environmental Protection Agency headquarters for him. Pablo Martinez Monsivais/AP hide caption

itoggle caption Pablo Martinez Monsivais/AP

Homeowners can receive up to $4,000 for replacing their lawns with less thirsty plantings, in a rebate program run by the Los Angeles Department of Water and Power. iStock hide caption

itoggle caption iStock

Flames from the Doce Fire rise above a hillside in Arizona's Prescott National Forest at dusk on June 18. Todd Tamcsin/American Red Cross via AP hide caption

itoggle caption Todd Tamcsin/American Red Cross via AP

The new rules' would reduce harmful emissions, the EPA says. David Paul Morris/Getty Images hide caption

itoggle caption David Paul Morris/Getty Images

Heron Island is located on the southern end of the Great Barrier Reef, about 25 miles off the northeast coast of Australia. Ted Mead/Getty Images hide caption

itoggle caption Ted Mead/Getty Images

A Ford Focus electric concept car with a home charging unit on display at the 2013 North American International Auto Show in Detroit, Mich., in January. Stan Honda/AFP/Getty Images hide caption

itoggle caption Stan Honda/AFP/Getty Images

A truck carrying hardwood timber drives along a rural road leading to Paragominas, Brazil, on Sept. 23, 2011. The city has become a pioneering "Green City," a model of sustainability with a new economic approach that has seen illegal deforestation virtually halted. Andre Penner/AP hide caption

itoggle caption Andre Penner/AP

A condemned house in the Ocean Breeze area of New York City's Staten Island. Most homes in the seaside community were inundated by the ocean surge from superstorm Sandy. John Moore/Getty Images hide caption

itoggle caption John Moore/Getty Images

Former South Carolina Republican Rep. Bob Inglis now runs the Energy and Enterprise Initiative. /Energy and Enterprise Initiative hide caption

itoggle caption /Energy and Enterprise Initiative

The Michigan Gala apples on this packing line will soon be in short supply. After a mild fall and winter, then a late-April freeze, Michigan's apple cultivation has dropped 90 percent. Noah Adams/NPR hide caption

itoggle caption Noah Adams/NPR