Countries by Carbon dioxide (CO2) emissions from Transport (Energy) (Mt CO2e)
The United States leads all 194 countries with 1,678.56 Mt CO2e in annual transport CO2 emissions, more than 1.8 times China's second-place total of 928.70 Mt CO2e. At the other end of the ranking, Dominica records just 0.03 Mt CO2e. The gap between first and last spans a range of over 5.9 million percent, reflecting the enormous differences in population, fleet size, and transport infrastructure across countries.
Ranking 2024
Analysis
This metric measures annual carbon dioxide (CO2) emissions from the transportation sector, expressed in megatonnes of CO2 equivalent (Mt CO2e) and standardized using AR5 global warming potentials. Per the source definition, it covers IPCC 2006 codes 1.A.3.a Civil Aviation, 1.A.3.b_noRES Road Transportation no resuspension, 1.A.3.c Railways, 1.A.3.d Water-borne Navigation, and 1.A.3.e Other Transportation. CO2 is one of the six Kyoto greenhouse gases. The data come from the World Bank World Development Indicators (indicator EN.GHG.CO2.TR.MT.CE.AR5), with a data year of 2024. Coverage is comprehensive: all 194 countries in the ranking have data from the last seven years, 100% of datapoints are classified as official quality, and the average year-over-year change across the dataset is 7.9%, well within the 50% volatility threshold. Twenty extreme outliers were identified at the 3-sigma level, predominantly at the top of the distribution.
The top of the ranking is heavily concentrated among the world's largest economies and most motorized nations. The United States ranks 1st at 1,678.56 Mt CO2e, a figure that exceeds the combined totals of ranks 3 through 10. China follows at rank 2 with 928.70 Mt CO2e, and India ranks 3rd at 344.35 Mt CO2e. The Russian Federation (rank 4, 286.72 Mt CO2e) and Brazil (rank 5, 219.29 Mt CO2e) round out the top five. Japan (rank 6, 174.90 Mt CO2e), Canada (rank 7, 166.30 Mt CO2e), and Indonesia (rank 8, 151.73 Mt CO2e) follow closely. High absolute values at the top reflect large populations, extensive road networks, and high freight volumes rather than any single factor.
The middle of the ranking shows notable variation among countries of comparable size. Poland (rank 21, 68.61 Mt CO2e) and Egypt (rank 22, 62.24 Mt CO2e) sit just above Nigeria (rank 23, 60.44 Mt CO2e) and Malaysia (rank 24, 60.28 Mt CO2e), despite having very different economic profiles. Canada (rank 7, 166.30 Mt CO2e) ranks higher than Germany (rank 11, 138.04 Mt CO2e) despite Germany's larger economy, illustrating how geography and transport mode mix affect totals. At the lower end, small island states and landlocked low-income countries cluster below 1 Mt CO2e. Dominica ranks last at 0.03 Mt CO2e, with St. Vincent and the Grenadines (rank 191, 0.045 Mt CO2e), St. Kitts and Nevis (rank 190, 0.046 Mt CO2e), and Kiribati (rank 192, 0.041 Mt CO2e) all recording similarly minimal figures.
Several data limitations are relevant to this metric. Because the measure covers only CO2 and not all greenhouse gases from transport, it excludes non-CO2 warming agents such as black carbon or nitrous oxide that also originate from transport combustion. The metric captures absolute emissions and does not account for population size, GDP, or per-capita transport activity, which means large countries rank high regardless of efficiency. Reporting reliability may vary for countries with limited statistical capacity, particularly in sub-Saharan Africa and some small island states, even though all 194 datapoints are classified as official. The 20 extreme outliers flagged at the 3-sigma level — concentrated at the top of the distribution — indicate that a small number of countries drive the statistical range disproportionately, which can compress apparent differences among mid- and lower-ranked nations.
Methodology
Data are drawn from the World Bank World Development Indicators, indicator code EN.GHG.CO2.TR.MT.CE.AR5, for the reference year 2024. The metric is defined as: a measure of annual emissions of carbon dioxide (CO2), one of the six Kyoto greenhouse gases (GHG), from the transportation sector (subsector of the energy sector) including IPCC 2006 codes 1.A.3.a Civil Aviation, 1.A.3.b_noRES Road Transportation no resuspension, 1.A.3.c Railways, 1.A.3.d Water-borne Navigation, 1.A.3.e Other Transportation. The measure is standardized to carbon dioxide equivalent using AR5 global warming potentials. The ranking covers 194 countries, all of which have data from within the last seven years (100% recency). Data quality is high: 100% of datapoints are classified as official. The average year-over-year change is 7.9%, indicating moderate volatility. Twenty extreme outliers were identified using a 3-sigma threshold, predominantly at the upper end of the distribution. The value range spans from 0.03 Mt CO2e (Dominica) to 1,678.56 Mt CO2e (United States), a spread of over 5.9 million percent. Rankings reflect absolute national totals and are not normalized for population, land area, or economic output.