Green Airlines

Rankings / Trends

Trends since 2000

Together, the ranked airlines went from 38.4 passenger-miles per gallon in 2000 to 60.6 in 2025, a change of 58%.

Efficiency of the whole industry

US airlines together: passenger-miles per gallonLine chart of passenger-miles per gallon for all ranked US airlines combined, 2000 to 2025.35404550556065200020052010201520202025Passenger-miles per gallonAll airlines
US airlines together: passenger-miles per gallonLine chart of passenger-miles per gallon for all ranked US airlines combined, 2000 to 2025.3040506070200020102025Passenger-miles per gallonAll airlines
All ranked airlines combined: total passenger-miles divided by total gallons.

The 6 largest airlines

The 6 largest airlines: passenger-miles per gallonLine chart comparing the 6 largest US airlines by passenger-miles per gallon over time.304050607080200020052010201520202025Passenger-miles per gallonAlaska AirlinesJetBlueSouthwest AirlinesUnited AirlinesDelta Air LinesAmerican Airlines
The 6 largest airlines: passenger-miles per gallonLine chart comparing the 6 largest US airlines by passenger-miles per gallon over time.304050607080200020102025Passenger-miles per gallonUnited AirlinesDelta Air LinesAmerican AirlinesSouthwest AirlinesAlaska AirlinesJetBlue
Largest 6 by seat-miles in 2025. Airlines with regional partners include them. Merged airlines start a new line in the year BTS combined their filings.

Total CO2

Efficiency per passenger-mile has improved, but the total depends on how much flying there is. Emissions from these airlines are at their highest in 2025, at 182.6 million tonnes.

CO2 from scheduled passenger flying, million tonnesLine chart of total CO2 from ranked US airlines scheduled passenger flying by year.80100120140160180200200020052010201520202025Million tonnes of CO2CO2
CO2 from scheduled passenger flying, million tonnesLine chart of total CO2 from ranked US airlines scheduled passenger flying by year.75100125150175200200020102025Million tonnes of CO2CO2
CO2 from jet fuel burned in scheduled passenger service, at 9.75 kg per gallon.

Year by year

YearPassenger-miles per gallonkg CO2 per passenger-milePassengers (millions)Fuel (billion gallons)CO2 (million tonnes)
202560.60.16197518.73182.6
202461.30.15998618.42179.6
202360.90.16094817.70172.5
202260.10.16285815.77153.7
202153.20.18367012.93126.1
202042.20.2313748.9987.6
201958.00.16893318.18177.2
201856.90.17189617.75173.1
201756.40.17385717.07166.4
201655.60.17583116.75163.3
201554.80.17880616.39159.8
201454.00.18177115.89154.9
201352.90.18475215.79154.0
201252.40.18674615.61152.2
201151.50.18974215.70153.1
201051.50.18973115.39150.0
200949.50.19771515.43150.5
200848.70.20075416.50160.9
200748.40.20178216.98165.5
200647.20.20775616.74163.2
200545.60.21475016.91164.9
200443.60.22471516.63162.2
200341.60.23465915.61152.2
200240.30.24262915.73153.4
200137.90.25764016.96165.4
200038.40.25468717.80173.6

Source: US Bureau of Transportation Statistics (BTS), Schedule P-12(a) fuel, T-100 traffic and regional Schedule T-2 filings; US EPA jet-fuel CO2 factor. See the methodology and glossary.