The Federal Aviation Administration computer incident that grounded thousands of U.S. flights. The Southwest Airlines holiday chaos. China’s COVID-19 resurgence bringing back requirements for negative tests before flights. Our air travel system has rarely looked so fragile as it has in recent weeks.

While these developments are enough to remind us what life would be like without air travel, they aren’t putting its long-term viability at risk. What really ought to be keeping industry and passengers awake at night is aviation’s greenhouse gas emissions problem.

Before the pandemic, aviation was responsible for roughly 2.5% of global GHG emissions—and passenger demand is most of the way back to that pre-pandemic level, projected to reach 85.5% of its 2019 high this year. These emissions are an existential threat to the industry’s environmental and financial sustainability. They lessen our tolerance for frivolous flying. They push us to buy carbon offsets. And they make some of us consider other modes of transportation altogether.

Air carriers have been exploring new fuels and other technologies to help them shrink their carbon footprints, even as consumption continues to grow. But the shift to cleaner fuel sources isn’t just happening in the air. It’s happening on the ground—at and around airports worldwide.

Dallas-Fort Worth and San Diego International have reached carbon neutrality through emissions reductions and carbon offsets. San Francisco International has a five-year plan to become “triple zero”—zero carbon, zero waste, zero net energy use. In France, Lyon-Saint Exupéry and Lyon-Bron airports have reforesting programs to create carbon sinks. New York’s JFK and Moi International, in Mombasa, Kenya, are using solar energy to act as backup during grid outages and to power passenger gates.

At Toronto Pearson airport, where I work, there is a growing understanding that airports are more than just fuel depots for airplanes. Actual airport operations are estimated to create 10% of aviation’s emissions, but airports are also cities in their own right—focal points for employment, growth, and supply chains, which makes them ideally placed to help reduce an even wider range of emissions on the ground.

“Airports employ extensive fleets of ground support vehicles, consume large amounts of energy for operations, serve as delivery points for jet fuel, and sit at the physical intersection of many complex economies of distribution and logistics. . . . The case for this kind of investment is clear,” says a recent report by the Innovation Economy Council, a Toronto-based research institute.

Here are four significant ways airports are working to reduce aviation emissions in the air and on the ground:

ELECTRIC VEHICLES

Airports will be increasingly asked to accommodate demand for electric charging in airport parking garages, park-and-fly lots, and storage and maintenance facilities. Demand for EV chargers will come from private vehicles, rental cars, and taxi and limousine fleets. At Toronto Pearson, there are 53 EV charging stations for private vehicles, and 85 more for ground support vehicles. Rental giants like Hertz are also moving into this area, including a recent agreement to purchase up to 175,000 EVs from General Motors over the coming five years.

SUSTAINABLE AVIATION FUEL

SAF, as it’s better known, is a renewable, drop-in alternative to jet fuel produced through the refinement and blending of organic feedstocks, such as agricultural waste products, animal fats, corn grain, or algae. Many major airlines and airports have been tinkering with SAF pilot programs, although there are worries about the availability of feedstocks.

The IEC report details how Edmonton International Airport plans to harness Alberta’s natural advantages in clean hydrogen production by using carbon capture and utilization, raising the prospect of recycling captured fuel carbon for SAF production. Meanwhile, organic feedstocks aren’t just being used for jet fuel—at London’s Gatwick, a waste management plant turns organic food waste and packaging into energy that powers the site’s water recovery system.

HYDROGEN

Hydrogen fuel cells produce no emissions and have better energy density than jet fuel. They’re seen as a long-term solution for aviation—after questions are answered regarding cost, storage, and safety. But in the short term, they are ideal for the ground-based vehicles we associate with airports and their surrounding businesses: forklifts, baggage tractors, shuttle buses, and cargo trucks. Large hub airports are strategically located to provide centralized hydrogen distribution or production facilities capable of serving nearby smaller and midsize businesses, such as warehouses. Many thousands of vehicles pass by each day, which is why clean hydrogen infrastructure is also being planned for truck and fleet refueling.

While hydrogen flight may be years away, the wheels are in motion on the ground. The airport in Stuttgart, Germany, just announced its intention to host a hydrogen test facility. Edmonton International is deploying hydrogen-powered shuttle buses, hydrogen fuel-cell rental vehicles, and hydrogen fueling stations. And Airbus has launched an initiative to work with multiple airports that are interested in building low-carbon hydrogen infrastructure.

EFFICIENCY GAINS

Changes in the design and materiality of modern aircraft have already helped to deliver 80% improvements in aviation’s fuel efficiency since the 1960s. A newer development is the evolution of on-board navigation used in approaches and landings. Airport systems that rely on satellite signals—an approach known as RNP AR, or required navigation performance with authorization required—are allowing newer aircraft to fly more precise paths and reduce the time, fuel, and emissions involved with a plane’s approach to land, saving dozens of gallons of fuel and thousands of pounds of emissions, even on short flights.

The first airport anywhere to take this step was Calgary International, in 2018. Toronto Pearson is one of the airports working to provide that option, in addition to a process called A-CDM, or airport collaborative decision-making, which allows us to share the right information with the right people at the right time. Our airport partners can anticipate arriving aircraft, prepare them for their next flights, and enable on-time departure with more efficient operations and less fuel consumption.

As hubs for the entire aviation industry, airports are ideally suited for building the infrastructure, convening the stakeholders, and helping to move them all toward more sustainable fuels and practices. There are no silver bullets for aviation sustainability. But while the majority of emissions are in the air, many of today’s most promising solutions—from sustainable fuels to efficiency gains to solutions that stretch beyond the airport itself—are on the ground.