United Airlines has the dual distinction of producing the most carbon emissions among U.S. passenger airlines last year, while also sourcing the most low-emission sustainable aviation fuel.
The Chicago-based carrier generated 30.4 million metric tons of scope 1 — or direct — carbon emissions in 2022, according to company data. That number is lower than, for example, American Airlines’ 34.6 million metric tons of scope 1 emissions. However, United does not include emissions from its regional affiliates in scope 1 while American does; adding regional to United’s number boosts its direct emissions to 36 million metric tons.
“While United is proud to have sourced the most SAF last year of any airline, we know we have a long way to go to reach our 2050 commitment of reducing our greenhouse gas emissions by 100%, without relying on traditional carbon offsets,” United’s Chief Sustainability Officer Lauren Riley said in a statement. SAF is short for sustainable aviation fuels.
After United, the biggest carbon emitters fell along size lines: American, Delta Air Lines, Southwest Airlines, JetBlue Airways, and Alaska Airlines, according to company data. The carriers generally ranked in the same order based on flights in 2022, Cirium Diio data show. United was the main outlier; it ranked third in terms of total flights in 2022 but also had the longest average stage length of the five airlines.
U.S. Major Airline Emissions 2022
In million metric tons
| Airline | Scope 1 | Scope 1 + regional |
|---|---|---|
| Alaska | 6.9 | 7.5 |
| American | 34.6 | 34.6 |
| Delta | 30.7 | 33 |
| JetBlue | – | – |
| Southwest | 18.6 | 18.6 |
| United | 30.4 | 36 |
Source: Airline Weekly analysis of company report
U.S. airline emissions were up across the board last year as the industry recovered from the pandemic. Flight numbers rebounded during the year despite operational issues that prompted schedule cuts during the summer. But even as flights rebounded, airlines were more focused on their carbon emission reduction goals than ever before. These became talking points among executives, and have resulted in numerous headline grabbing deals for everything from SAF supply agreements to electric or hydrogen-powered aircraft, and even pie-in-the-sky SAF-powered supersonic planes.
All of the investments come as the global airline industry targets net-zero carbon emissions by the middle of the century. While each airline has its own specific plan to achieving this, there is broad consensus that wide adoption of SAFs will drive the greatest reduction in emissions. SAFs, which can be made from everything from used cooking oil to “green” hydrogen, can generate no more than half the lifecycle emissions as traditional jet fuel and often result in reductions of 80% or more. SAF feedstocks also cannot compete with foodstuffs and cannot contribute to deforestation or other externalities.
Only about 79 million gallons, or roughly 300 million liters, of SAF was produced around the world last year, according to IATA data. That represents “virtually nothing” in terms of global airline fuel needs, the organization’s chief economist Marie Owens Thomsen said in June. Scaling SAF production to meet the need will be a “journey.”
In the U.S., United was also at the top of the list of SAF users. The airline secured 3 million gallons of the fuels last year, triple the number in 2021, its data shows. American followed with 2.6 million gallons, Delta with 1.6 million, JetBlue 661,000, and Alaska with roughly 300,000. Southwest did not disclose SAF usage for 2022.
U.S. Major Airline Fuel Use 2022
In million gallons
| Airline | Jet Fuel | Sustainable Aviation Fuel |
|---|---|---|
| Alaska | 702 | 0.3 |
| American | 3,601 | 2.6 |
| Delta | 3,412 | 1.6 |
| JetBlue | – | – |
| Southwest | 1,922 | – |
| United | 3,139 | 3 |
Source: Airline Weekly analysis of company report
To be clear, SAF amounted to, as Thomsen put it, “virtually nothing” of U.S. airline fuel use as well. The same four airlines that disclosed SAF usage last year consumed 10.9 billion gallons of jet fuel over the same period.
The European Union and U.S. governments want to change this. Both have enacted policies designed to stimulate the SAF industry, though they have taken different tracks. The EU is putting mandates in place that require airlines to use the fuels for a percentage of their fuel needs in the bloc; the mandate starts at 2% in 2025 and rises in steps to 6% by 2030 and eventually 70% by the middle of the century. On the other hand, the U.S. enacted tax incentives for SAF producers in the 2022 Inflation Reduction Law.
Airlines, however, are split over how to scale SAF production. There is near universal agreement that governments need to do something but some, including Emirates President Tim Clark, think the industry needs to do more to stimulate the market.
“If we rely on government, if we rely on other entities to do things, we may be waiting a long time. We can’t wait that long. We’ve got to do better than that,” Clark said in June.
Updated with JetBlue emissions and fuel data, and corrected IATA number for 2022 SAF production.
