Associated Press: The amount of heat-trapping carbon dioxide in the air jumped dramatically in 2012, making it very unlikely that global warming can be limited to another 2 degrees as many global leaders have hoped, new federal figures show.
Scientists say the rise in CO2 reflects the world's economy revving up and burning more fossil fuels, especially in China.
Carbon dioxide levels jumped by 2.67 parts per million since 2011 to total just under 395 parts per million, says Pieter Tans, who leads the greenhouse...