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

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

A map depicts temperature changes over the past 20 years, compared to the average between 1901 and 1960. "The period from 2001 to 2011 was warmer than any previous decade in every region," according to the National Climate Assessment. NOAA NCDC/CICS-NC hide caption

itoggle caption NOAA NCDC/CICS-NC

Wind generators at Pacific Hydro's Cape Bridgewater wind farm in Warrnambool, Australia, in May 2012. Each generator produces roughly enough energy to meet the annual needs of 12,000 households. Mark Dadswell/Getty Images hide caption

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Climate activists at a rally in Doha on December 1, 2012. Karim Jaafar/AFP/Getty Images hide caption

itoggle caption Karim Jaafar/AFP/Getty Images

Former Vice President Al Gore. Jon Kalish/NPR hide caption

itoggle caption Jon Kalish/NPR

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

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The redder the shading, the further above average were the temperatures in September. NOAA's National Climatic Data Center hide caption

itoggle caption NOAA's National Climatic Data Center

A farmer sifts through the drought-stricken topsoil of his Logan, Kansas, land in August 2012. John Moore/Getty Images hide caption

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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