If you often fly long distances, those trips are probably the largest part of your carbon footprint. In Sweden, the problem spawned the new word “flygskam,” or “flight shame,” and a growing number of people are pledging not to fly. For airlines, cutting emissions is challenging, and large electric jets may still be a couple of decades away. But a United flight from Chicago to Los Angeles today, June 5, demonstrates how much is already possible.
Instead of regular jet fuel, the flight is using a biofuel blend. “Biofuel is extraordinarily important to us as we seek to reduce our greenhouse gas emissions,” says Aaron Robinson, senior manager for environmental strategy and sustainability at United. The company started first using biofuel in flights from LAX in 2016, working with a nearby supplier. Another supplier near Chicago, which makes biofuel from household waste, will start delivering fuel in a few years. (United owns a stake in the company.) Jet fuel accounts for roughly 99% of the carbon footprint of a flight; pure biofuel shrinks emissions 60%, and using a biofuel blend can cut fuel emissions by 18%. On the flight from Chicago to L.A., United will buy carbon offsets to cover the rest of the emissions, supporting a Conservation International project in Peru that helps local farmers find economic alternatives to cutting down trees in a protected forest.
During the flight, passengers will be served a free meal with recyclable and compostable tableware instead of standard snacks in multiple hard-to-recycle packages. The company will test a new paper coffee cup that can be easily recycled. “We’re really testing out different options to get customer feedback on them, and truly understand how we can operationalize this more in the future,” says Aaron Stash, senior manager for environmental sustainability and stakeholder engagement at United. Each change requires careful analysis: Initially, the company wanted to switch to reusable silverware, but because the amount of fuel a plane uses is so sensitive to weight, using slightly heavier forks is actually worse for the environment. If the test goes well, United may begin using the new tableware on its international flights, where it already serves full meals.
The pilots on the flight will use every possible technique to optimize efficiency. The methods aren’t new, but aren’t always implemented. “We want to be flying the right altitude at the right speed, the most direct routing,” says Robinson. “Given airspace constraints, that’s not always possible. So sometimes we’ll have to take circuitous routings or maybe around weather. Ideally, we would be slowly having the aircraft climb over the course of the flight.” On the ground, the flight will use electric-powered ground equipment instead of standard diesel models.
All of this is difficult to scale up on all of United’s flights. Some airports don’t yet have the infrastructure for electric ground equipment, for example. The supply of biofuel is growing, but still very limited, and technical constraints mean that the biofuel still has to be blended with regular jet fuel. But there will soon be more options. New startups capturing CO2 emissions from power plants or directly from the air can also make new fuel with a dramatically smaller footprint. And the airline will likely eventually use electric planes–though that will take time.
“We’re interested in electric aircraft,” says Robinson. “But the reality is that that technology is not going to be available to us for quite some time. The current projections are that you have a regional aircraft available in 2030 or so, and then a mainline-sized domestic airplane probably 10 or 15 years after that.” The expense of current planes also means that airlines want to use them as long as possible, so the company is focused on biofuel. “The industry has made a very conscious decision of taking the approach of having sustainable fuels that are compatible with our existing aircraft because that’s what we believe is the cheaper, more affordable solution to get to those goals [of reducing emissions] in a faster timeframe,” Robinson says.