環境：運輸部門における二酸化炭素排出量 - 国土交通省
https://www.mlit.go.jp/sogoseisaku/environment/sosei_environment_tk_000007.html

Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022 | US EPA
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2022