The title is very unassuming - Record High 2010 Global Carbon Dioxide Emissions from Fossil-Fuel Combustion and Cement Manufacture Posted on CDIAC Site.
Greenhouse gases increased by 5.9 percent from 2009 to 2010. Biggest Jump Ever in Global Warming Gases explains that despite the poor global economy, there was an increase in travel and manufacturing in 2010.
But if there is one single factor - it is coal. CO2 emissions from coal were up almost 8 percent in 2010. That of course, is the preferred new energy for India and China as they rapidly modernize and expand their economies.
I don't have the international data, but the data on the left provides an explanation of the increased CO2 production within the US. About 1 percent is due to population increase, 2 percent because of increased productivity, 0.7 percent because our products require more energy to produce than previously, and 0.2 percent because the energy we used released additional carbon (such as coal instead of natural gas).
To be fair, the US greenhouse gas production is still considerably below its peak in 2007. What troubles scientists though, is the increased greenhouse gas production by China and India. Andrew Weaver of University of Victoria summarized it, saying, "We really need to get the developing world because if we don't, the problem is going to be running away from us."