Countries by Nitrous oxide (N2O) emissions from Transport (Energy) (Mt CO2e)
China ranks first in nitrous oxide (N2O) emissions from transport with 23.15 Mt CO2e, followed closely by the United States at 20.68 Mt CO2e. At the opposite end, Dominica and the British Virgin Islands each record just 0.0003 Mt CO2e. The gap between the top and bottom of the ranking spans more than 7.7 million percent, reflecting the extreme variation in transport activity and fleet size across 194 countries.
Ranking 2024
Analysis
This metric measures annual nitrous oxide (N2O) emissions from the transportation sector, expressed in megatonnes of carbon dioxide equivalent (Mt CO2e). According to 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, standardized to carbon dioxide equivalent using AR5 global warming potentials. The data are drawn from the World Bank World Development Indicators (indicator code EN.GHG.N2O.TR.MT.CE.AR5) for the reference year 2024. Coverage is comprehensive: all 194 countries in the dataset have data from the last seven years, and 100% of datapoints carry official status. The viability checks identified 21 extreme outliers at the 3-sigma threshold, and average year-over-year volatility is 8.8%, well within acceptable bounds.
China (rank 1, 23.15 Mt CO2e) and the United States (rank 2, 20.68 Mt CO2e) are the two dominant emitters, together accounting for a disproportionate share of global transport N2O. India ranks third at 7.48 Mt CO2e, a substantial drop from the top two. Iran (rank 4, 4.51 Mt CO2e) and Brazil (rank 5, 3.59 Mt CO2e) are the next largest, with Russia (rank 6, 3.57 Mt CO2e) close behind. Canada (rank 7, 2.07 Mt CO2e) and Japan (rank 8, 1.83 Mt CO2e) follow, with Indonesia (rank 9, 1.76 Mt CO2e) and Saudi Arabia (rank 10, 1.67 Mt CO2e) rounding out the top ten. High absolute values at the top of the ranking correspond with large populations, extensive road networks, and high vehicle counts.
In the middle of the ranking, several European countries cluster tightly: Germany ranks 14th at 1.31 Mt CO2e, France 15th at 1.14 Mt CO2e, and the United Kingdom 17th at 1.12 Mt CO2e. Thailand (rank 16, 1.14 Mt CO2e) falls between France and the UK, a notable placement for a middle-income economy. Singapore, despite its status as a major logistics hub, ranks 91st at just 0.066 Mt CO2e, reflecting its small land area. Luxembourg ranks 110th at 0.041 Mt CO2e. At the lower end, small island states and landlocked microstates dominate: Dominica and the British Virgin Islands share rank 193 at 0.0003 Mt CO2e, and St. Vincent and the Grenadines ranks 192nd at 0.0004 Mt CO2e.
A key limitation of this metric is that it measures absolute emissions, not emissions per capita or per unit of GDP, which means larger countries rank higher regardless of efficiency. Countries with large informal transport sectors or incomplete fuel consumption records may underreport emissions. The metric excludes non-energy transport emissions and resuspension effects (as indicated by the 1.A.3.b_noRES code). Territorial reporting conventions mean that emissions from international aviation and shipping may be attributed inconsistently across countries. The 21 extreme outliers flagged at the 3-sigma threshold warrant particular scrutiny, as they may reflect genuine scale differences or data irregularities.
Methodology
Data are sourced from the World Bank World Development Indicators, indicator code EN.GHG.N2O.TR.MT.CE.AR5, with a reference year of 2024. The metric is defined as: a measure of annual emissions of nitrous oxide (N2O), 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. The ranking covers 194 countries, all of which have data from within the last seven years (100% recency). All datapoints are classified as official quality (100%). The viability checks identified 21 extreme outliers at the 3-sigma threshold. Average year-over-year change is 8.8%. Values range from 0.0003 Mt CO2e (British Virgin Islands, Dominica) to 23.15 Mt CO2e (China), a spread of over 7.7 million percent. Higher values indicate greater absolute transport N2O emissions. No per-capita or intensity normalization is applied.