Emissions reduction, sustainable fuel & innovation in Environmental sustainability

Our goal is to decarbonize aviation. To do this means more sustainable fuel, better efficiency, and new technology. It means investing in our future through direct action now.

Global aviation accounts for about 3% of global greenhouse gas (GHG) emissions and is one of the toughest sectors to decarbonize. Full-scale solutions to decarbonize the airline industry will take time, making it even more critical that a company like United invests today in technology for the long-term. We are committed to investing in new technologies and taking tangible steps that have the potential to permanently reduce our emissions from flying.

Sustainable Aviation Fuel

For over a decade United has led the industry in developing sustainable aviation fuel (SAF). We are committed to investing in innovative technologies that will measurably reduce the speed of climate change, which is why United has invested in more SAF production than any other airline to date. And in 2021 we flew the first ever passenger flight using 100% SAF in one engine, to demonstrate the scalable and impactful way companies can join together to address the climate crisis.

Infographic, a timeline of firsts.

  • 2013, United partakes in the first commercial-scale supply agreement for sustainable aviation fuel
  • 2015, United invests in Fulcrum BioEnergy, becoming the first U.S. airline to invest in a SAF company.
  • 2016, United becomes the first U.S. airline to use renewable SAF for regularly scheduled flights.
  • 2018, 2050 Goal; SFO-ZRH longest transatlantic SAF flight. 2019, Renewal of World Energy agreement.
  • 2021, First commercial flight using 100% SAF

Reducing United’s environmental footprint

Today, nearly all (98%) of United’s GHG emissions are from the combustion of fossil jet fuel. Reducing our consumption of conventional jet fuel by maximizing our fuel efficiency and working to replace the conventional jet fuel we use with an alternative, SAF, is the nearest-term and fastest mechanism for United to reduce its emissions. SAF is an alternative fuel derived from renewable or waste products that can reduce lifecycle GHG emissions by up to 85% compared to conventional jet fuel. In addition, SAF is “drop-in” ready, meaning it is interchangeable with conventional jet fuel and requires no modifications to our aircraft engines or airframes. This also makes it compatible with the existing fuel distribution and storage infrastructure at airports. United has long championed the development, deployment and commercialization of SAF and invested in more SAF production than any other airline. Some of our SAF accomplishments include:

  • In 2015, United made a $30 million equity investment in Fulcrum BioEnergy, Inc. Fulcrum, a company that has developed a process for converting municipal solid waste into SAF, entered into a long-term supply agreement with United, with the opportunity for United to purchase up to 900 million gallons of SAF.
  • In 2016, United became the first airline globally to use SAF in regular operations on a continuous basis. To date, we’ve used more than 5 million gallons of SAF produced by World Energy, at its Paramount, CA facility, at the Los Angeles International Airport.
  • In 2021, United launched its first-of-its-kind Eco-Skies Alliance program, with two separate enrollments in which corporate partners agreed to collectively fund the price premium for approximately 7.1 million gallons of SAF.
  • In September 2021, United made a joint investment with Honeywell UOP in Alder Fuels, a new clean tech venture developing a first-of-its-kind low-carbon crude technology to accelerate large-scale SAF production. United also agreed to purchase up to 1.5 billion gallons (enough to fly more than 57 million passengers) of SAF from Alder Fuels.
  • In December 2021, United made aviation history by operating the first passenger flight using 100% SAF, in one engine, from Chicago to Washington, D.C. The flight showcased the safety of SAF and the potential for a dramatically reduced carbon footprint for aviation.

Fuel efficiency

As a foundation to the scaled development and use of SAF, United is concentrated on introducing newer, more fuel-efficient aircraft into its fleet as well as improving the efficiency of its existing fleet.

  • From 1990 to 2021, United improved its mainline fuel efficiency more than 30%.
  • In the second quarter of 2021, United announced United Next and entered into firm narrow-body aircraft orders for 200 Boeing 737 MAX aircraft and 70 Airbus A321neo aircraft, which are expected to have an 11% overall improvement in fuel efficiency and 17-20% lower carbon emission per seat compared to older planes.
  • In conjunction with its SAF mission and improving the fuel efficiency of its fleet, United has been revamping its flight and ground operations, implementing operational and procedural initiatives to drive fuel conservation.
  • Over 4,000 units of United’s ground service equipment (GSE) around the world are electric or use alternative fuels and, as of the end of 2021, nearly 32% of its GSE fleet have been electrified.
  • United has worked collaboratively across its organization and with Air Traffic Control providers to improve fuel efficiency through the implementation of best practices by providing training to its pilots and dispatchers and supplying them with the tools needed to execute on those strategies.

Innovating in carbon reduction technology

United has been forming partnerships with and investing in early-stage climate technology companies that have the potential to scale and support United’s climate targets, or are generally supportive of advancing sustainability within the broader economy. In June 2021, United launched a new corporate venture capital fund, United Airlines Ventures, Ltd. (UAV), to focus our efforts on these investments.

  • In February 2021, United announced an investment in, and agreement to work with, Archer Aviation to accelerate the development and production of their electric aircraft. This is an urban mobility solution that has the potential to serve as an “air taxi,” giving United an opportunity to accelerate the development of clean technologies on a broader scale and its customers another opportunity to reduce their carbon footprint before they even board a United flight.
  • In July 2021, UAV announced that, along with Breakthrough Energy Ventures and Mesa Airlines, it invested in electric aircraft startup Heart Aerospace Incorporated. Heart Aerospace is developing the ES- 19, a 19-seat electric aircraft that has the potential to fly customers up to 250 miles with zero emissions when powered by renewable electricity.
  • In December 2021, United became the largest airline to invest in hydrogen-powered engines for regional aircraft with a new equity stake in engine developer, ZeroAvia, Inc. These hydrogen-powered electric fuel cell engines support the retrofit of select narrow-body engines, replacing fossil fuel burning engines with zero carbon alternatives.

Carbon capture – direct air capture

To achieve our goal of 100% green by having net zero emissions by 2050, we believe aviation will rely on carbon removal technologies in its suite of climate technologies. Our climate strategy extends beyond reducing our emissions to focus on atmospheric carbon removal and utilization. We are investing in carbon capture technologies to sequester carbon and also to potentially utilize and recycle captured carbon to make low-carbon fuels.

Airline decarbonization is a major challenge and direct air capture (DAC) technology is one of the few pathways to address the GHG emissions associated with aircraft emissions with its potential to scale and capture millions of metric tons of CO2 per year. The captured CO2 can either be permanently, safely, and securely stored deep underground, or utilized as a feedstock to make synthetic fuels (known as power-to-liquid fuels).

  • In 2020, along with our commitment to become 100% green by 2050, United announced a commitment to invest — the first to be announced in the aviation industry — in DAC technology.
  • In March 2022, United Airlines Ventures (UAV) and Oxy Low Carbon Ventures announced an investment in biotech firm Cemvita Factory to commercialize the production of SAF intended to be developed through a revolutionary new process using CO2 and synthetic microbes.

Emissions data

Our detailed 2020 environmental data is available in the data section of this report. 2021 data will be collated, verified and reported when available in late H1 2021.

External verification

United obtains third-party verification of our greenhouse gas emissions on an annual basis. ERM Certification and Verification Services (ERM CVS, a wholly owned subsidiary of the ERM Group, a global market leader in sustainability services) conducts our emissions verification and provides an ISO 14064-3 limited assurance on our greenhouse gas (GHG) emissions for reporting.

Download our external assurance statement for our GHG emissions ➔