Why you should feel a little less guilty about flying

Quitting Carbon is a 100% subscriber-funded publication. To support my work, please consider becoming a paid subscriber or making a one-time donation.

Aviation emissions are one of the most intractable pieces of the climate puzzle to solve. If not curbed, global emissions from aviation could triple by 2050, according to the International Civil Aviation Organization (ICAO).

For climate-conscious people everywhere, boarding a plane often comes with a pang of guilt.

It is because the long-term trends for the sector are so bleak that I was so pleased to learn just how extensive the efforts underway are to tackle emissions from aviation.

At a forum co-hosted last week by the California Air Resources Board (CARB) and South Coast Air Quality Management District (SCAQMD) at CARB’s headquarters in downtown Sacramento, stakeholders from government, industry, and academia met over two days to update each other on technology solutions to reduce pollution from flying.

I left the forum more optimistic than I had expected about the potential for governments to bring aviation’s soaring emissions under control.

California joins the fight

My biggest reason for optimism is the fact that California has joined the fight.

California’s early efforts to crack down on air pollution predate the federal Clean Air Act, giving the Golden State more power to establish its own environmental regulations than any other state. California has used that power to force the cleanup of cars and trucks. It now aims to do the same for the aviation sector.

Whereas the rules agreed to at the ICAO are technology-following – the result of a lowest-common-denominator consensus reached between airlines and plane makers – the rules coming from CARB will be technology-forcing. They will bite.

California’s environmental regulators adopt long-term emissions targets and give industry technology-neutral flexibility to figure out how to meet them.

The purpose of last week’s forum was to give stakeholders a chance to present available technologies that will inform the proposal CARB staff will bring to its Board in 2027 to reduce emissions from on-ground operations at airports. To meet federal ozone standards, CARB has committed to adopt “programs and policies to reduce NOx emissions from airport and aircraft operations to the maximum extent practicable.”

In July 2024, CARB agreed to a Joint Statement on Advancing Emissions Reductions with SCAQMD and the U.S. Environmental Protection Agency. A few months later, in October, CARB and the Airlines for America trade association committed to a goal of boosting sustainable aviation fuel supply in California to 200 million gallons by 2035 – an amount equivalent to 40% of intrastate aviation fuel demand.

Based on presentations at the forum, here's a quick look both at the status of the aviation sector’s push to reduce its emissions and measures that could be included in CARB’s aviation proposal in two years’ time.

Reducing emissions from ground support equipment

There is a lack of near-term, affordable alternatives to the fossil fuel-based jet fuel consumed by commercial airlines but that doesn’t mean that easy wins aren’t available today to reduce emissions from the aviation sector.

It turns out, for instance, that many of the luggage carts and belt loaders, catering trucks and cargo loaders, tugs and tow tractors that service planes at the boarding gate have already been electrified or will be soon. CARB estimates there are 12,000 pieces of ground support equipment (GSE) operating at California airports today but just 26% are fully electric.

These fleets are poised for a rapid zero-emissions transition at airports around the world.

Los Angeles International Airport has committed to 100% zero-emission GSE fleet by 2033. The Port Authority of New York and New Jersey has mandated 100% zero-emission GSE at its major airports by 2030, with JFK’s new Terminal One set to debut the world’s first centralized all-electric GSE fleet in 2026.

Outside the U.S., the Royal Schiphol Group, which runs Amsterdam’s Schiphol airport, will make “all non-aircraft traffic at ground level emission free” by 2030. And London’s Heathrow is making plans for zero-carbon infrastructure across the airport by the mid-2030s.

Reducing emissions when taxiing

Commercial airliners consume so much jet fuel when the main engines are running that shaving even a few minutes of fuel burn can lead to substantial savings. Using a zero-emissions tug when taxiing a plane to the runway can do just that.

Safran Landing Systems is working to commercialize an on-board eTaxiing system that is attached to two of the plane's four wheels and is used to reduce the need for a tug to roll the plane to or from the gate. The system would be under pilot control and is planned for future newly built planes.

Smart Airport Systems (SAS) is working with airlines around the world to commercialize a semi-robotic hybrid towing system called the TaxiBot* designed for taxiing airplanes from the boarding gate to the takeoff runway. The system, which could be made fully autonomous, if allowed by regulations, and can be fully electrified, has already been trialed at Schiphol airport. The system can reduce fuel consumption and CO₂ and NO_x emissions by up to 85% during taxi, according to SAS.

Utah Valley University lecturer Brett Stone is working with a team of graduate students to develop an autonomous electric aircraft tug. The team has already demonstrated the electric tug, which can be controlled in the cockpit or remotely, with a Cessna plane and is looking to scale up to regional 737-scale aircraft pending funding and a willing airport partner.

CARB said it plans to issue a Request for Proposal for a zero-emission taxiing pilot at a California airport this year.

Reducing emissions at the gate

Another often-overlooked easy climate win is simply plugging planes in at the gate. In the same way that large container ships or oil tankers can save fuel and avoid emissions by plugging into shore power at berth, planes can turn off their main and auxiliary engines by plugging into ground power at the gate.

To save fuel, pilots can turn off the main engines and turn on an auxiliary power unit (APU) typically located in the tail of the plane to power computers, lights, and HVAC systems at the gate. The problem? The APU still runs on jet fuel.

In California, 95% of airport gates have ground power infrastructure available but pilots and ground crews plug in planes only one-third of the time, according to CARB. A simple remedy would be for CARB to require planes to plug into ground power while at the gate, which could be enforced by requiring airports to use thermal or acoustic cameras, or other means, to monitor APU usage.

One speaker at the forum, Tim Toerber with the airport operations optimization startup Assaia, called on CARB to implement just such a rule statewide by 2026. He noted that the plane’s APU status is not on most pilots’ checklists and that airlines don’t always have access to their own APU usage data.

He added that an APU monitoring policy could include fines for non-compliance and said it would give airlines leverage with pilot unions to ensure that APUs are turned off when planes are at the gate.

The human necessity for flight

Addressing aviation’s climate burden is a moral imperative but there is an equivalent obligation to do all we can to preserve the use of a conveyance that closes the distance between us and enriches all our lives.

Fortunately, even minor tweaks can yield big results. Zurich’s airport, for instance, managed to trigger a steep decline in visits by high-NO_x-polluting planes simply by assessing higher landing fees against such aircraft.

CARB is considering requiring similar revenue-neutral, emissions-based landing fees at California airports. Such fees would be used to incentivize the cleanest aircraft in their categories – such as the Bombardier CRJ-700 (regional jet), Airbus A319 NEO (narrow-body jet), and Boeing 787-8 Dreamliner (wide-body jet) – to land at California airports.

The ability to board a plane and cross continents and oceans to visit friends, family, and colleagues is one of the miracles of modern life. There is no replacement for seeing people and places in person. I don’t want to give it up.

What I heard last week leaves me a bit more hopeful that solutions are at hand so that none of us are forced to make that choice.

*This section was updated to include recent developments with the commercialization of the TaxiBot.