Global carbon emissions last year exceeded worst-case scenario predictions from just four years before, according to the US Department of Energy (DOE). A rise of 6 percent (564 million additional tons) over 2009 levels was largely driven by three nations: the US, India, and China. Emissions from burning coal jumped 8 percent overall. The new data, supported by a similar report from International Energy Agency (IEA), makes it even more difficult for nations to make good on a previous pledge to hold back the world from warming over 2 degrees Celsius.