It’s easy to look up at a plane streaking across the sky and think only of the adventure it represents—the trip to see family, the business meeting across the country, the long-awaited vacation. But that same plane also represents one of the hardest climate puzzles of our time. Aviation produces roughly 2.5 percent of global carbon dioxide emissions, and unlike many other industries, it hasn’t found an easy path to clean energy. The recent backlash over Taylor Swift’s private jet travel is just one flashy reminder of a much bigger issue: we love to fly, and we have no obvious way to make flying harmless to the planet. The trouble is that jet fuel is almost impossibly efficient at what it does. It packs enough energy into every gallon to carry a plane nonstop from New York to Singapore. Batteries simply can’t match that range, and hydrogen, while promising, requires redesigned aircraft and complicated new fuel systems. That’s why many experts and airlines are betting on sustainable aviation fuel, or SAF, as the most realistic near-term answer. SAF is a “drop-in” fuel, meaning it can be mixed with or replace conventional jet fuel without modifying the planes or airport infrastructure. Alaska Air Group, the parent company of Alaska Airlines and Hawaiian Airlines, has become a vocal proponent of this approach. As Ryan Spies, managing director of sustainability at Alaska and Hawaiian Airlines, puts it, “SAF really fits a need that we have today and long into the future. We don’t have to change our planes, we don’t have to change what’s happening at the airport.” That simple fact makes SAF feel less like a futuristic experiment and more like a practical bridge to a cleaner aviation industry.
What makes sustainable aviation fuel so different from the fuel we use now is where it comes from. Conventional jet fuel is made by pumping oil from deep underground, which releases carbon that was locked away for millions of years. SAF, on the other hand, starts with carbon that is already part of the surface world. It can be made from used cooking oil, animal fats, oil-rich plants, farm and forestry waste, or even captured carbon dioxide. The point is to recycle carbon already in circulation rather than introduce new carbon from beneath the earth. This idea is being put into practice in the American West, where two very different companies are working to make SAF a commercial reality. One of them is Twelve, a startup with a futuristic facility in Moses Lake, Washington, a town surrounded by agricultural land and tumbleweeds. Twelve’s AirPlant One opened last year and began producing SAF from captured carbon dioxide this summer. The facility looks like something out of a science fiction film: a giant white tank holds carbon dioxide captured as a byproduct of ethanol production, and the gas is then pumped through silver pipes into devices that strip away oxygen and add hydrogen from water, turning it into hydrocarbons that can power a jet engine. The entire process is powered by low-cost, carbon-free hydropower, which is one reason the region has attracted clean-tech companies. Twelve’s technology can also produce naphtha, a precursor to plastics, but the main attraction is its E-Jet fuel, which is designed to cut flight emissions by up to 90 percent compared with conventional jet fuel. The facility is designed to make 50,000 gallons of SAF per year, which sounds small, but it’s just the beginning. Chief executive Nicholas Flanders says customer demand already outstrips what AirPlant One can supply, and the company is planning a much larger facility that would produce tens of millions of gallons annually.
About seven hours east of Moses Lake, in Great Falls, Montana, another company is taking a completely different route to the same goal. Montana Renewables has converted part of an old oil refinery into a renewable fuel production facility. Instead of building from scratch, it repurposed infrastructure that has been around for a century, which Matt Upmeyer, vice president of commercial, calls “the most economical way to produce renewable fuels like SAF.” The company uses feedstocks like used cooking oil, beef tallow from rendering plants, and camelina, a hardy cover crop that helps farmers improve soil health while producing oil-rich seeds. Montana Renewables started making SAF in 2023 and by the following year had become the largest producer of sustainable aviation fuel in North America. The company can currently produce 60 million gallons of SAF per year and hopes to reach 200 million gallons by the end of 2028. Those numbers sound impressive, but they are still nowhere near enough to solve the challenge. The U.S. government set a goal of producing 3 billion gallons of SAF annually by 2030, though a recent academic study involving researchers at Washington State University suggests the country can probably reach only about 2.1 billion gallons by then. Airlines in the United States consume roughly 20 billion gallons of jet fuel a year, and that number keeps rising. This gap between production and demand is the central tension in the SAF story. Even with all the excitement around new facilities and new technologies, sustainable aviation fuel currently makes up only about 1 percent of the fuel used by Alaska Air Group. It is a hopeful start, but there is a long way to go before SAF becomes ordinary.
One of the biggest obstacles to wider adoption is cost. Sustainable aviation fuel is more expensive than traditional jet fuel, and the gap fluctuates with global oil prices. Ryan Spies of Alaska Air Group offers some rough comparisons. SAF made from fats, oils, and greases, which is the most common form today, typically sells for less than double the price of conventional jet fuel. But SAF made from captured carbon, like the fuel produced by Twelve, has the greatest environmental benefit, Spies says, and is “multiple times more expensive.” That price premium is a formidable barrier for airlines, which operate on razor-thin margins. Policy can help close the gap, and governments have tried different approaches. The United States has used what might be called carrots, such as a tax credit of up to $1.75 per gallon created in 2022, though that credit was reduced to $1 after President Trump returned to office. Europe has opted for sticks, requiring that 2 percent of jet fuel be SAF starting last year, with the United Kingdom raising the requirement to 3.6 percent this year. These mandates create guaranteed demand, which encourages producers to invest in building more capacity. Another important piece of the puzzle is the growing number of customers signing long-term fuel purchase agreements. These deals lock in prices and send a signal to producers that there is a market waiting for their product. Alaska Airlines and Microsoft partnered with Twelve in 2022 to support the development of its fuel, and that kind of early commitment is crucial. As Twelve’s Nicholas Flanders explains, getting customers to sign these long-term agreements “is really important for securing project financing.” Without those guarantees, it is nearly impossible for a startup to raise the enormous sums needed to build a commercial-scale SAF facility.
It is natural to wonder whether sustainable aviation fuel is truly worth the effort. After all, SAF still produces carbon dioxide when burned in a jet engine. But the key difference is in the carbon cycle. Petroleum-based jet fuel releases carbon that would otherwise remain buried underground, adding new greenhouse gas to the atmosphere. SAF releases carbon that is already part of the surface system, whether it came from a plant, an animal, or the atmosphere itself. So while the smoke from a SAF-powered plane looks the same, the impact on the climate is dramatically different. Most SAF produced today offers an 80 percent reduction in emissions compared with fossil jet fuel, and Twelve’s captured-carbon approach can reach 90 percent when factoring in the energy used for production and transportation. To put that in perspective, Nicholas Flanders says that a domestic flight running on Twelve’s E-Jet fuel would have the same emissions per passenger mile as riding the London Tube. Imagine taking a cross-country flight and feeling as good about your climate impact as you would about taking a train. That is the promise of SAF. But SAF is not the only tool available for cleaning up aviation. There are other strategies that can work alongside it, such as designing more efficient aircraft, preventing contrail formation, and using flight plans that minimize fuel burn. Together, these approaches could meaningfully reduce the environmental footprint of flying while we still struggle to make long-haul air travel possible on any other kind of clean energy. The urgency is real. As other sectors like electricity and road transport shift toward renewable power, aviation’s share of global carbon emissions is expected to grow. The industry cannot wait for a miracle battery or a hydrogen revolution. It needs solutions that work with the planes we already have, using the infrastructure we already built, and fit into the lives of travelers who simply want to get where they’re going.
In the end, sustainable aviation fuel is not a perfect answer, but it is an honest and practical one. It acknowledges that people will keep flying for decades to come, and that demanding they stop would be both unrealistic and unfair in a world that depends on air travel for trade, family, and culture. Instead, SAF gives us a way to make the planes in the sky today significantly cleaner. The two Western facilities show what this future looks like in very different forms. Twelve’s Moses Lake plant is a gleaming monument to high-tech innovation, transforming captured carbon into fuel with the help of clean hydropower. Montana Renewables is a study in industrial grit, taking an old oil refinery and turning it into a center for renewable fuel, proving that legacy infrastructure can be repurposed for a new era. Neither approach is a silver bullet, and neither is currently producing enough fuel to replace fossil jet fuel on a meaningful scale. But every new facility, every long-term purchase agreement, and every ambitious production target moves the industry closer to a tipping point. The challenges are real: cost, policy uncertainty, limited feedstocks, and the enormous scale of airline fuel demand. Yet the momentum is also real. Airlines are signing agreements, governments are setting mandates, and companies are innovating in ways that were unthinkable just a few years ago. Taylor Swift may have been ridiculed for her private jet flights, but the conversation she sparked has pushed sustainable aviation fuel further into the public eye. That is a small, strange silver lining. As more people understand where their emissions come from and what can be done about them, the pressure will grow on airlines, fuel producers, and lawmakers to make clean flying the norm. Aviation will never be perfectly green, not in the near future, but with sustainable aviation fuel leading the way, it can become far better than it is today. For anyone who loves to fly, that is a feeling worth chasing.
