Estimates show that 2010 was by far a record year for CO₂ emissions from fossil-fuel combustion and cement manufacture. Globally 9,139 Teragrams, a teragram is a million metric tons, of oxidized carbon (Tg-C) were emitted from these sources.

Converted to carbon dioxide, so as to include the mass of the oxygen molecules, this amounts to over 33.5 billion metric tons of carbon dioxide. The increase alone is about 512 Tg-C, or 5.9%, over the 2009 global estimate. The previous record year was 2008, with 8,749 Tg-C emitted; the 2010 estimate is about 104.5% of that, or 391 Tg-C more.

Much of the 5.9% global increase from 2009 to 2010 is due to increased emissions from the world's largest fossil-fuel emitter, the People's Republic of China, where emissions rose 10% to 2.247 Tg-C.

Emissions from the United States remain well below 2007 levels, an indicator of dire economic conditions.  Currently it is estimated that emissions are back at around 1995 levels in the US.

John Reilly, co-director of MIT's Joint Program on the Science and Policy of Global Change, told the Associated Press that large yet developing nations like India, China and Mexico, all exempt from Kyoto, are responsible for the continued rise. Developed countries produced about 60 percent of the world's greenhouse gases in 1990 and now are responsible for less than 50 percent.

A manuscript report on these latest numbers has been submitted for peer review and the preliminary numbers are here. A report on last year's update with some of the methodology involved was published Nature Geoscience last year: Friedlingstein P., R.A. Houghton, G. Marland, J. Hacker, T.A. Boden, et al. 2010. Update on CO₂ emissions. Nature Geoscience. 3 811-812, doi 10-1038/ngeo1022.
The general methodology used to produce the 2009 and 2010 estimates is described at:
http://cdiac.ornl.gov/ftp/trends/emissions/Preliminary_CO2_Emissions_Explaination.doc