Melting at the base of this Texas-sized ice pack in the Amundsen Sea off Antarctica could lead to significant ocean level rise in the long term. This image of the ice shelf was taken on the first flight of Ice Bridge from an altitude of 20,000 feet. NASA hide caption

itoggle caption NASA

A farmer harvests corn on a farm near Spring Mills, Pa. According to current biofuel laws, if you burn ethanol from corn in your car, the government doesn't count the carbon dioxide that comes out of the tailpipe as an actual carbon emission. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

A customer looks at a display of televisions in a Best Buy store in San Francisco. California state regulators are currently considering ways to reduce the power consumption of flat-panel televisions. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images