Wind turbines at the San Gorgonio Pass Wind Farm in Whitewater, Calif., in 2012. Bloomberg via Getty Images hide caption

itoggle caption Bloomberg via Getty Images

Thousands of "fairy circles" dot the landscape of the NamibRand Nature Reserve in Namibia. Why these barren circles appear in grassland areas has puzzled scientists for years. N. Juergens/AAAS/Science hide caption

itoggle caption N. Juergens/AAAS/Science

This photo from a Kyodo News helicopter shows a flame of natural gas from a Japanese deep-sea drilling ship on Tuesday. This successful extraction of methane from the seafloor was a world first. Kyodo/Landov hide caption

itoggle caption Kyodo/Landov

Scientists say they have put together a record of global temperatures dating back to the end of the last ice age, about 11,000 years ago. This historical artwork of the last ice age was made by Swiss geologist and naturalist Oswald Heer. Oswald Heer/Science Source hide caption

itoggle caption Oswald Heer/Science Source

In this Sept. 1, 2008, photo released by Wildlife Conservation Society, a male forest elephant strides across Langoue Bai, Gabon. Elizabeth M. Rogers/Wildlife Conservation Society via AP hide caption

itoggle caption Elizabeth M. Rogers/Wildlife Conservation Society via AP

American Electric Power's natural gas-burning plant in Dresden, Ohio, is one of the energy company's new investments in alternatives to coal-burning plants. Michael Williamson/The Washington Post/Getty Images hide caption

itoggle caption Michael Williamson/The Washington Post/Getty Images

The Boston Tea Party museum sits right on the edge of the harbor. With rising sea levels and the increasing threat of strong storms, buildings like these are at particular risk of flooding. Christopher Joyce/NPR hide caption

itoggle caption Christopher Joyce/NPR

Plosky Tolbachnik volcano erupts in Russia's Far Eastern Kamchatka Peninsula on Jan. 6, 2013. It's not a so-called "super volcano," but every million years or so scientists say the Earth burps up volcanoes that can erupt for thousands of years. Alexander Petrov/AP hide caption

itoggle caption Alexander Petrov/AP

Highly detailed sonar systems aboard the research vessel Pritchard gave researchers a clear view of the sediment on the seafloor off Long Island. Courtesy of John Goff/University Of Texas hide caption

itoggle caption Courtesy of John Goff/University Of Texas

A United Airlines 787 Dreamliner arrives at O'Hare international Airport in Chicago in November. Aviation authorities in the U.S. and abroad have grounded the planes because of problems with batteries on board. Nam Y. Huh/AP hide caption

itoggle caption Nam Y. Huh/AP

Much of the money from the Hurricane Sandy relief bill the House of Representatives passed will fund beach and infrastructure restoration projects in areas such as Mantoloking, N.J., seen on Oct. 31. Doug Mills/AP hide caption

itoggle caption Doug Mills/AP

A woman with the Army Corps of Engineers documents a destroyed home last month in a residential area of New Dorp Beach on Staten Island in New York City. Robert Nickelsberg/Getty Images hide caption

itoggle caption Robert Nickelsberg/Getty Images

A forest near Trieste, Italy, is largely dead owing to drought stress during the summer of 2012. Andrea Nardini/Nature hide caption

itoggle caption Andrea Nardini/Nature

Energy Of The Future? California company Sierra Energy is testing out a reactor that turns garbage — like these wood chips, metal fragments and plastics — into synthetic gas that can then be turned into a low-carbon diesel fuel. Christopher Joyce/NPR hide caption

itoggle caption Christopher Joyce/NPR