CO2 emissions
Annual territorial carbon dioxide emissions in megatonnes of CO2 equivalent.
How it is measured
Estimated from fossil fuel consumption, cement production, and land-use data, compiled by the Global Carbon Project.
Where the number came from
Charles Keeling began continuously measuring atmospheric CO2 at Mauna Loa in 1958, producing the curve that made the accumulation undeniable; attributing that accumulation to countries came later and is a different kind of problem, because the atmosphere does not record passports. The UN Framework Convention on Climate Change, agreed in 1992, settled on territorial accounting, meaning emissions are assigned to the country where the fuel was burned, and national inventories have been reported on that basis ever since. The Global Carbon Project, established in 2001, publishes the annual budget that most independent series including ours are built on. Territorial accounting was chosen because it is what a government can actually measure and regulate, not because it is the fairest possible allocation, and essentially every dispute about climate responsibility is an argument about that choice.
Worked example: three ways to say who emits the most, all of them true
Our 2024 figures put China at about 12,289 megatonnes, the United States at roughly 4,904 and India at about 3,193, with Germany near 572. On that basis China emits about two and a half times as much as the United States and the ranking looks settled. Switch to the per-person view on the companion field and it inverts: the United States is at roughly 14.2 tonnes per person, China about 8.7 and India about 2.2, so an average American emits more than six times an average Indian. Both statements come from the same underlying data and answer different questions, one about what the atmosphere receives and one about how a society lives. There is a third framing neither column shows. Territorial accounting assigns emissions to the place the fuel was burned, so a steel plant in China that exports to Germany counts against China; consumption-based accounting, which the Global Carbon Project also publishes, reassigns those emissions to the importer and typically raises wealthy importing economies by several percent while lowering export manufacturers. And a fourth: cumulative emissions since industrialisation, which is what actually drives warming, puts the United States and Europe far ahead of China regardless of any current-year table. If you are using this field to make an argument about responsibility, say which of the four you mean.
Figures read from our own co2 emissions table; each row there carries its observation year and whether it came from a live feed or the frozen archive.
Our data source
Our World in Data, CO2 and Greenhouse Gas Emissions (CC BY 4.0), built on the Global Carbon Budget. It covers 215 entities against the World Bank’s 203 and runs a year ahead, so the World Bank series (EN.GHG.CO2.MT.CE.AR5) is kept only as a fallback.
Refresh cadence: Annual, roughly one-year lag; taken on each rebuild.
What to watch for
Territorial accounting: emissions embodied in imports count against the producer, not the consumer. Consumption-based accounting would raise wealthy importers and lower export manufacturers.
CIA World Factbook equivalent field: "Carbon dioxide emissions" (frozen at the January 2026 final edition; our figures continue from live sources).