In 2018 U.S. states with the highest shares of carbon dioxide (CO2) emissions coming from transportation were primarily located along the eastern and western coasts, with California, Hawaii, and Washington having the highest share at 59%, followed closely by Idaho at 58%. The four lowest states were Louisiana (19%), North Dakota (15%), West Virginia (14%), and Wyoming (12%). Nationally, 37% of CO2 emissions were from transportation.
Note: Based on energy-related CO2 data for five sectors—residential, commercial, industrial, electric utilities, and transportation.
Source: U.S. Energy Information Administration, Energy-Related CO2 Emission Data Tables, Table 4.