Carbon dioxide emissions in the United States declined in all 50 states between 2005 and 2023, according to new data from the U.S. Energy Information Administration (EIA). During this period, total energy-related CO2 emissions nationwide dropped by 20%. At the same time, the country’s population grew by 14%, resulting in a 30% decrease in per capita CO2 emissions.
New Jersey achieved a greater reduction than the national average, with a 36% decrease in CO2 emissions per capita. The EIA attributed most of the decline across the country to reduced coal use for electricity generation. More electricity is now produced from natural gas—which emits about half as much CO2 as coal—and from non-emitting sources such as wind and solar power.
Maryland saw the largest reduction among states, with a 49% drop in per capita CO2 emissions from energy consumption over this period. Other significant reductions occurred in Washington, D.C. (48%), Georgia (45%), Delaware (43%), and North Carolina (42%). In contrast, Mississippi experienced only a 1% decrease, while Idaho and South Dakota saw declines of just 3% and 4%, respectively.
In most coastal states along both the east and west coasts, transportation was responsible for the highest share of CO2 emissions in 2023. These states tend to have higher population densities and more road and air travel. Many no longer use coal for electricity generation, leading to lower electric power sector emissions since 2005.
The industrial sector was responsible for most CO2 emissions in four states: Texas, Louisiana, Alaska, and Iowa. In these areas, large oil, natural gas refining operations or significant agricultural activity contributed to higher industrial emission levels.
Looking forward, EIA projects that total U.S. CO2 emissions will rise slightly—by about one percent—in 2025 due to increased fossil fuel consumption related to crude oil production and growth in electricity generation.
