Carbon emissions in the USA during 2011 are likely to below 1998 levels. Emissions in 2011 will also be below the 2010 mark. Those are the conclusions from EIA data at www.eia.gov/totalenergy/data/monthly/pdf/sec12_3.pdf
What explains the USA's real progress on reducing carbon emissions?
America is using production, energy more efficiently with energy consumption at 2000 levels, rampimg up sharply all renewables, including biofuels as a substitute for oil, and continues to shift from coal to gas for electricity production. Coal on a lifecycle basis emits twice the carbon pollution to make electricity as gas does.
Other pollutants like mercury, nox, sox are also declining sharply, in part for the same reasons that drive carbon emission declines and in part because 60% of coal plants now have installed pollution controls for non-carbon, traditional pollutants and comply with the new EPA cross state air pollution rule and the proposed EPA Air Toxic Rule.