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

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

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

itoggle caption John Moore/Getty Images

A man stands in a fountain in Washington Square Park on July 18, in New York City. Temperatures were expected in the upper 90's during another heat wave in the city. Mario Tama/Getty Images hide caption

itoggle caption Mario Tama/Getty Images

Scientists blame higher levels of carbon dioxide in Pacific Ocean waters caused by global warming for the failure of oyster seeds to thrive in hatcheries. Eric Risberg/AP hide caption

itoggle caption Eric Risberg/AP

Climate change as predicted in 1981. Grey shows predictions from global temperature rise via computer models run of Hansen et al 198. Red shows real world data taken since paper was published. Geert Jan van Oldenborgh and Rein Haarsma, KNMI, RealClimate hide caption

itoggle caption Geert Jan van Oldenborgh and Rein Haarsma, KNMI, RealClimate