Aviation emissions are responsible for about 3.5 percent of the climate change our planet is experiencing, according to NOAA. And while different airlines have varied strategies for dealing with this issue, one carrier, United Airlines, is taking an approach that stands apart: it does not rely on voluntary carbon offsets.
Purchasing voluntary offsets can mean funding an outside project that helps the environment, such as planting trees, and most other commercial airlines in the world are taking this route to net zero. But if a company’s goal is to reduce its impact, rather than compensate for it, United officials contend that buying offsets isn’t enough. “You’ve got to make it less about marketing and more about doing the right thing. And we have to get executives learning what is really zero as opposed to what is a marketing effort for zero,” said United CEO Scott Kirby.
United’s team is leaving no stone unturned in its search for ways to reduce fuel consumption and energy usage. It’s tapping every available resource, scrutinizing every aspect of the aircraft, investing in technologies like electric aircraft and hydrogen fuel cell engines and optimizing every phase of the operation. The goal is to put it all together to create a flight experience that is not only safe and comfortable—but net zero in emissions by mid-century. “We’re embracing a new goal to be 100 percent green by 2050 by reducing our greenhouse gas emissions 100 percent. And we’ll get there not with flashy, empty gestures, but by taking the harder, better path of actually reducing the emissions associated with flying,” Kirby said.
This commitment puts United ahead of the curve when it comes to rapidly evolving federal and international regulations around emissions. The airline believes that aviation policy should include subsidies for clean-energy initiatives, similar to those that benefit the EV and solar industries. This could accelerate innovation and make green solutions more cost competitive.
It starts with the fuel
United’s sustainability efforts begin on the farm, on the ground, with its Sustainable Aviation Fuel (SAF) partners. These partners are sourcing raw materials like forestry and agricultural waste or used oil as feedstock. Fuel made from some of these materials emits as much as 85 percent less greenhouse gas emissions than petroleum-based fuel like conventional Jet A or Jet A-1, on a lifecycle basis, and are capable of being blended and dropping right into existing aircraft engines with no modifications.
The proof point came in December 2021, which marked a historical moment in the history of air travel. A short trip—just under two hours from Chicago to Washington, D.C.—saw a United Airlines 737 MAX 8 make the world’s first passenger flight using 100% SAF in one engine. CEO Kirby was aboard with 114 other passengers.
It was a major step within a journey that has been years in the making, marked by some big milestones along the way.
In 2010, United began publicly sharing its emissions data—guided by its conviction that environmental transparency is critical to gaining support from its aviation peers, customers and policymakers.
In 2016, United became the first airline globally to use SAF in regular operations on a continuous basis.
In April, 2021, United launched the Eco-Skies Alliance program, a first of its kind initiative in which United’s corporate customers can reduce their emissions from travel on United by contributing funds that go toward the increased purchase of SAF.
In September, 2021, United announced an agreement to purchase up to 1.5 billion gallons of SAF, the largest publicly announced commitment in aviation history.
2022 and beyond, United plans to continue integrating SAF into its operations while its venture fund, United Airlines Ventures (UAV), takes stakes in SAF-related companies such as Dimensional Energy. This will enhance an existing portfolio that already includes producers like Alder Fuels and Fulcrum BioEnergy.
Earlier this year, UAV, created in 2021 as a mechanism to support the airline’s net-zero goals by investing in companies that are pursuing clean-energy pathways, announced an investment in biotech firm Cemvita Factory. The goal is to commercialize SAF developed through Cemvita’s revolutionary production process, which uses CO2 and synthetic microbes.
These investments are intended to support United’s efforts to secure more SAF for its flights. To date, United has used more than five million gallons of SAF at Los Angeles International Airport.
Compared to conventional jet fuel, SAF costs significantly more to produce, so the current market remains small. Further financial incentives are needed to make SAF production scalable. This is why United is collaborating with entities ranging from the Biden Administration to the sustainable aviation fuel lobby to make SAF more readily available and more affordable. “We realize there’s a limit to what a single company can do alone,” said Kirby.
Collective industry efforts to garner federal support for sustainable aviation appear to be paying off, as the recently passed Inflation Reduction Act contains the first ever federal provisions for tax credits to specifically incentivize SAF production.
Greener on the ground
At airport facilities across the country, United’s commitment to reduce emissions becomes tangible and visible.
Various projects at United’s hubs in Chicago, Houston and San Francisco have achieved LEED certification, which means they meet the globally recognized standard for environmental sustainability—from water usage, to energy efficiency to green building materials and more.
According to United’s 2021 report to the CDP, an international nonprofit that helps companies disclose their environmental impact, the United Cargo building at O’Hare International Airport sports one of the largest green roofs in Chicago, helping convert carbon monoxide into oxygen and filtering pollution from the air.
Slide to compare
The United Club location in Terminal 7 at LAX has achieved gold-level certification through Audubon International’s Green Hospitality program. Among the club’s innovations is a composting program that helps reduce the energy needed to process solid waste and lessens the airline’s contributions to landfills.
Earlier this year, United opened a new club at Newark Liberty International Airport. The 30,000 square-foot space features a host of innovations that promote sustainability, including enhanced indoor air quality, green cleaning methods and EPA WaterSense-rated fixtures that reduce water waste from amenities such as private showers. While most people think that conserving water is only an issue for drought-plagued areas, the fact is that wasted water contributes to carbon emissions due to the power needed to pump fresh water to homes and businesses and to treat sewage and runoff.
Getting it right in pre-flight
As United aircraft roll up to the gate, more procedural and operational changes towards sustainability are in play. For example, the crew where possible avoids the use of the aircraft’s jet fuel-powered auxiliary power unit during boarding, relying instead on alternative, emissions-reducing energy sources to power at-the-gate air conditioning and electricity for passenger comfort and preflight operations.
While taxiing, pilots can shut down one engine and taxi on the other, which conserves five million gallons of fuel per year—equivalent to removing 9,000 cars from the road. And rather than taxi from gates to hangars in between flights, United manages a fleet of nearly 70 SuperTug vehicles across 10 airports to tow aircraft instead. This alone saves eight million gallons of fuel per year.
Preparing for take-off, sustainability measures continue to unfold. Electric ground service equipment (GSE) is being added in place of gas and diesel-powered vehicles at United’s terminals worldwide. Now, at major hubs like Los Angeles, Houston and San Francisco, approximately three out of five of these ground service vehicles buzzing about the runway with luggage and personnel are electric-powered or use alternative fuels. One such electric vehicle, of which United was the first user in North America, cuts greenhouse gas emissions by 90 percent compared to a similar gas-fueled vehicle.
More broadly, United is working to embed sustainability across its supply chain, including vendor management and product procurement, to support its larger climate objectives.
Paper and planes
In the air as it is on the ground, reducing emissions is all about achieving new heights of fuel efficiency. The forthcoming 200 Boeing 737 MAX and 70 Airbus A321neo, both in the pipeline for United, are expected to have an 11 percent overall improvement in fuel efficiency and 17 to 20 percent lower carbon emissions per seat compared to older aircraft. Meanwhile, the airline is adding to its Boeing 787 Dreamliner fleet. The aircraft is 20 percent more fuel efficient than a typical, similarly sized plane, thanks in part to its lightweight, composite airframe and aerodynamic features such as raked wingtips, which reduce drag by 5.5 percent.
United Airlines Airbus A321neo
In Production:
200 Boeing 737 MAX & 70 Airbus A321neo
Expected to have an 11 percent overall improvement in fuel efficiency and 17 to 20 percent lower carbon emission per seat compared to older aircraft.
Delivering Now:
Boeing 787 Dreamliners
20 percent more fuel efficient than a typical, similarly sized plane. Features such as raked wingtips reduce drag by 5.5 percent.
United’s sustainability team also is constantly scrutinizing in-flight amenities—and looking for lighter-weight alternatives, because the lighter the plane, the less fuel it consumes, and the less emissions it produces. For example, one little change in the paper weight on which United’s in-flight magazine is printed managed to save 170,000 gallons of fuel per year—along with nearly 200 trees. Another 220,000 gallons per year—and 2,100 metric tons of CO2—were saved when teams chose lighter stock for the in-flight services guide.
When it’s time to land, United pilots are trained to request a continuous descent approach from air traffic controllers. This avoids having to constantly apply thrust to attain and hold different vectors and altitudes on the journey down, saving significant fuel while reducing noise pollution. United also has announced a conditional agreement to purchase up to 100, 19-seat electric airplanes from a Swedish startup, potentially for use on regional routes.
United says it has improved its overall fuel efficiency by 45 percent from 1990 to 2021—with more emissions-reducing innovations coming soon. “It’s no longer enough for us to connect the world without making sure it has a future,” said United CEO Kirby.