Maine saw the greatest percentage decrease in CO2 emissions with a 27 percent, or 6 million metric ton, reduction. New York experienced the greatest absolute decline at 52 million metric tons, or a 25 percent reduction. The state with the greatest percentage and absolute increase was Nebraska, at 28 percent (11 million metric tons).
From 2012 to 2013, 16 states saw a decrease in emissions, while 34 experienced an increase. This is reflected in the national data for 2013 as energy-related emissions were up about 2.5 percent.
Variations in the amount of emissions per capita can be attributed to climate, the structure of a state’s economy, population density, energy sources, building standards and state emission reduction policies. The 2013 CO2 emissions in Wyoming were 117 metric tons per capita, the highest in the US. North Dakota came in at number two with 78 metric tons of CO2 emissions per capita. West Virginia (50 metric tons per capita), Alaska (49 metric tons per capita), and Louisiana (42 metric tons per capita) round out the top five states in terms of per capita CO2 emissions.
New York had the lowest per capita CO2 emissions — 8 metric tons per capita. This can be attributed to readily available mass transit, a concentration of multi-family housing units and the fact that New York’s economy is oriented toward low-energy-consuming activities such as financial markets. In addition, New York’s energy prices are relatively high, which in turn encourages energy savings. The other states with lowest per capita CO2 emissions — all around 9 metric tons per capita — include California, Connecticut, Rhode Island and Vermont.
EIA’s analysis assigns all emissions related to the primary energy consumed to the state where that electricity is produced rather than where it is consumed. As a result, the states that produce electricity from fossil fuels and sell that electricity across state lines tend to have higher per capita CO2 emissions than states that consume more electricity than they produce.
The analysis also found that states exhibit very different emissions profiles by fuel type, and there can also be significant variations in terms of CO2 emissions by sector (residential, transportation, etc.).