The global output of heat-trapping carbon dioxide jumped by the biggest amount on record, the U.S. Department of Energy calculated, a sign of how feeble the world's efforts are at slowing man-made global warming.
The new figures for 2010 mean that levels of greenhouse gases are higher than the worst case scenario outlined by climate experts just four years ago.
"The more we talk about the need to control emissions, the more they are growing," said John Reilly, co-director of MIT's Joint Program on the Science and Policy of Global Change.
The world pumped about 564 million more tons (512 million metric tons) of carbon into the air in 2010 than it did in 2009. That's an increase of 6 percent. That amount of extra pollution eclipses the individual emissions of all but three countries — China, the United States and India, the world's top producers of greenhouse gases.
It is a "monster" increase that is unheard of, said Gregg Marland, a professor of geology at Appalachian State University, who has helped calculate Department of Energy figures in the past.
Extra pollution in China and the U.S. account for more than half the increase in emissions last year, Marland said.