European bison, or wisents, keep a safe distance from human visitors to their enclosure on the property of Prince Richard of Sayn-Wittgenstein-Berleburg in Germany's densely populated state of North Rhine-Westphalia. Soraya Sarhaddi Nelson /NPR hide caption

itoggle caption Soraya Sarhaddi Nelson /NPR

A decal advertising E85 ethanol is displayed on a pump at a gas station in Johnston, Iowa. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Chief Almir of Brazil's Surui tribe attends a press conference with Google representatives in Rio de Janeiro last year. Chief Almir has brought technology to his previously isolated people, who now use smartphones to send photos of illegal logging in the Amazon. Vanderlei Almeida /AFP/Getty Images hide caption

itoggle caption Vanderlei Almeida /AFP/Getty Images

An Arizona restaurant sold lion meat burgers in 2010 in an attempt to drum up business during the World Cup soccer tournament held in South Africa. Matt York/AP hide caption

itoggle caption Matt York/AP

For the first time, new nationwide science standards recommend teaching K-12 students about climate change. hide caption

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Workers clear honey from dead beehives at a bee farm east of Merced, Calif. Marcio Jose Sanchez/AP hide caption

itoggle caption Marcio Jose Sanchez/AP

The city of Gladstone near the Great Barrier Reef is the world's fourth largest coal-export hub. Dredges, like one seen here, have turned the harbor brown as they work to expand the coal port. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR