The Energy Department's Energy Information Administration said that 2000-10 emissions declined in 32 states. That trend is reversing, however, with 14 states showing declines from 2009-10.
Texas ranked highest with more than 652 million tons of CO2 emitted in 2010. Vermont and the District of Columbia ranked lowest with 6 million and 3.3 million tons, respectively. Wyoming had the highest per-capita level with around 118.5 million tons of CO2 emitted.
The EIA said emissions levels vary according to state size, climate, population density and dominate industry type.
In terms of renewable energy, the EIA said it expected consumption of green energy will increase by 3.3 percent this year, led by renewable resources other than hydropower. For coal, the EIA said emissions would decline if policymakers enacted tighter regulations on greenhouse gas emissions.
The EIA stated that emissions should decline as renewable energy resources gain momentum against coal. For 2040, the EIA estimates that energy-related CO2 emissions should be 28 percent lower than 2005 totals.
The state-by-state analysis wasn't meant as a policy audit. Some of the variables in greenhouse gas emissions since 2010 were attributed to U.S. economic recovery.