WASHINGTON — New U.S. Energy Department figures show the biggest jump ever in heat-trapping carbon dioxide pumped into the atmosphere last year.

That means levels of greenhouse gases are higher than the worst case scenario outlined by climate experts just four years ago when they warned about the pace of manmade global warming. The increase in emissions was spurred by big pollution surges from China and India, which are building more coal-fired power plants.

Energy Department officials say an improving world economy in 2010 also contributed. China is the world’s top producer of greenhouse gases, followed by the United States and India.