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

Wild bees, such as this Andrena bee visiting highbush blueberry flowers, play a key role in boosting crop yields. Left photo by Rufus Isaac/AAAS; Right photo courtesy of Daniel M.N. Turner hide caption

itoggle caption Left photo by Rufus Isaac/AAAS; Right photo courtesy of Daniel M.N. Turner

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

The Racetrack area in Death Valley National Park, which boasts one of the darkest night skies in the U.S. Dan Duriscoe/National Park Service hide caption

itoggle caption Dan Duriscoe/National Park Service

Carnegie Lake, Australia, 1999 Carnegie Lake in Western Australia fills with water only during periods of significant rainfall. In dry years, it is reduced to a muddy marsh. Flooded areas appear dark blue or black, vegetation appears in shades of dark and light green, and sands, soils and minerals appear in a variety of colors. NASA hide caption

itoggle caption NASA

WBT radio's bomb shelter in Charlotte, N.C., part of a government-funded emergency communications network, as it looked in 1963. Courtesy of Jerry Dowd hide caption

itoggle caption Courtesy of Jerry Dowd