US Airlines Are Getting Worse at Emitting CO2, Study Says
Airlines around the globe are failing to significantly reduce their carbon emissions, a new environmental report shows.
US airlines in particular dropped several spots overall in a list of international airlines' CO2 emission, compared to 2017's numbers.
Aviation accounts for about 2% of the world's overall carbon dioxide emissions, according to the UN's International Civil Aviation Organization. CO2 directly contributes to global warming. According to the new study, from German environmental nonprofit organization Atmosfair, no airline in the world reached the top level of carbon emission reduction, dubbed "level A" in the report; just two carriers reached the second-highest level, "B," mainly because their fleets are fuel efficient and more environmentally friendly than some older gas guzzling commercial planes.
The levels of environmental efficiency range from A to G, with G being the worst possible ranking. There were a total of 125 airlines scored. Low-cost carriers were ranked separately, as their business models differ from mainstream carriers and "renders them not-comparable to other airlines" regarding carbon emissions, the study said.
"Airlines which achieve the best results are those using modern equipment, having high seating density and high rates of passenger occupancy and load utilization," Atmosfair said in its report, which was released on Monday. So even though increasingly cramped seating might frustrate you on flights, it could ultimately be better for the environment.
To tabulate the rankings, Atmosfair used data from ICAO to "calculate the CO2 per net load kilometer for each flight based on aircraft type, engine, seat and cargo capacity and load factor."
Taking the top spot as the most fuel efficient airline is the UK's TUI Airways. It snagged the highest ranking because it "flies consistently with highly efficient aircraft (e.g., B737-800)," the report says. "Seating reaches almost maximum capacity. Combined with very high occupancy rates, even compared to the previous year, TUI Airways scores winning points."
All US airlines' rankings got worse, as compared to last year's list.
Alaska Airlines was the only US carrier to crack the top 25 of the most climate-friendly airlines, tied with Shandong Airlines, Sichuan Airlines and Thai Airways International for No. 22 with a level C ranking. It dropped several spots from 2017's list, on which it scored the No. 14 spot.
Other US airlines fared even worse in the report. Delta Air Lines scored a level D ranking and clocked in at No. 45 on the overall list, falling from No. 41 last year. United also earned level D status, coming in at No. 50 on the list, likewise falling nine spots from last year's ranking of No. 41. Hawaiian Airlines fell one spot to No. 57 and a level D environmental tier.
It's also worth noting that the regional subsidiaries of all the major US carriers scored significantly worse across the board (Delta Connection and United Express scored Fs, Alaska Horizon got a D). This is likely because the aircraft operating on shorter regional routes are less fuel efficient.
American Airlines was the only US carrier to actually improve its CO2 pollution score, nabbing the No. 58 ranking in 2018's list, up from No. 66 in 2017 (though it was still in the level D tier). AA was able to move up eight slots due to "high occupancy on long-haul flights in combination with more efficient aircraft," the study says. AA has been phasing out its older and less fuel efficient MD-80s in favor of more fuel efficient planes, particularly the Airbus A320, Boeing B737-800 and B777.
Bringing up the rear of the mainstream carriers was South African Airlink at No. 125 and a level G ranking.
Among the low-cost carriers, US airlines Frontier, Southwest and Spirit received level C rankings, while JetBlue and Allegiant were placed in the D level. Budget airlines were not given a numerical rank.
Many of these airlines have so-called "carbon offset" programs that are said to decrease their carbon footprints — usually by a customer donation to a chosen environmental initiative that helps to reduce CO2 emissions.
Below are the top-10 most carbon-friendly airlines in the world.
Top 10 Most Climate-Efficient Airlines:
1. TUI Airways(UK)
2. LATAM Airlines Brasil (Brazil)
3. China West Air (China)
4. TUIfly (Germany)
5. Transavia France (France)
6. SunExpress (Turkey)
7. Thomas Cook Airlines (UK)
8. Air Europa Express (Spain)
9. Condor Flugdienst (Germany)
10. Juneyao Airlines (China)
TPG featured card
at American Express's secure site
Terms & restrictions apply. See rates & fees.
| 3X | Earn 3X Miles on Delta purchases. |
| 1X | Earn 1X Miles on all other eligible purchases. |
Pros
- Delta SkyClub access when flying Delta
- Annual companion ticket for travel on Delta (upon renewal)
- Ability to earn MQDs through spending
- Various statement credits for eligible purchases
Cons
- Steep annual fee of $650
- Other Delta cobranded cards offer superior earning categories
- Earn 100,000 Bonus Miles after you spend $6,000 or more in purchases with your new Card within the first 6 months of Card Membership and an additional 25,000 bonus miles after you make an additional $3,000 in purchases on the Card within your first 6 months, starting from the date that your account is opened. Offer Ends 04/01/2026.
- Delta SkyMiles® Reserve American Express Card Members receive 15 Visits per Medallion® Year to the Delta Sky Club® when flying Delta and can unlock an unlimited number of Visits after spending $75,000 in purchases on your Card in a calendar year. Plus, you’ll receive four One-Time Guest Passes each Medallion Year so you can share the experience with family and friends when traveling Delta together.
- Enjoy complimentary access to The Centurion® Lounge in the U.S. and select international locations (as set forth on the Centurion Lounge Website), Sidecar by The Centurion® Lounge in the U.S. (see the Centurion Lounge Website for more information on Sidecar by The Centurion® Lounge availability), and Escape Lounges when flying on a Delta flight booked with the Delta SkyMiles® Reserve American Express Card. § To access Sidecar by The Centurion® Lounge, Card Members must arrive within 90 minutes of their departing flight (including layovers). To access The Centurion® Lounge, Card Members must arrive within 3 hours of their departing flight. Effective July 8, 2026, during a layover, Card Members must arrive within 5 hours of the connecting flight.
- Receive $2,500 Medallion® Qualification Dollars with MQD Headstart each Medallion Qualification Year and earn $1 MQD for each $10 in purchases on your Delta SkyMiles® Reserve American Express Card with MQD Boost to get closer to Status next Medallion Year.
- Enjoy a Companion Certificate on a Delta First, Delta Comfort, or Delta Main round-trip flight to select destinations each year after renewal of your Card. The Companion Certificate requires payment of government-imposed taxes and fees of between $22 and $250 (for itineraries with up to four flight segments). Baggage charges and other restrictions apply. Delta Basic experiences are not eligible for this benefit.
- $240 Resy Credit: When you use your Delta SkyMiles® Reserve American Express Card for eligible purchases with U.S. Resy restaurants, you can earn up to $20 each month in statement credits. Enrollment required.
- $120 Rideshare Credit: Earn up to $10 back in statement credits each month after you use your Delta SkyMiles® Reserve American Express Card to pay for U.S. rideshare purchases with select providers. Enrollment required.
- Delta SkyMiles® Reserve American Express Card Members get 15% off when using miles to book Award Travel on Delta flights through delta.com and the Fly Delta app. Discount not applicable to partner-operated flights or to taxes and fees.
- With your Delta SkyMiles® Reserve American Express Card, receive upgrade priority over others with the same Medallion tier, product and fare experience purchased, and Million Miler milestone when you fly with Delta.
- Earn 3X Miles on Delta purchases and earn 1X Miles on all other eligible purchases.
- No Foreign Transaction Fees. Enjoy international travel without additional fees on purchases made abroad.
- $650 Annual Fee.
- Apply with confidence. Know if you're approved for a Card with no impact to your credit score. If you're approved and you choose to accept this Card, your credit score may be impacted.
- Terms Apply.
- See Rates & Fees