Amazon’s fleet of aircraft, which is soon to surpass 80 Boeings, enables the e-commerce giant to deliver everything from dog food to Dysons within two days. It’s an impressive logistical feat, but it comes with a heavy carbon footprint — and is particularly conspicuous given the company’s recent pledge to achieve net-zero emissions by 2040. To start to address the issue, Amazon Air announced on Wednesday that it will buy up to 6 million gallons of sustainable aviation fuel, which it says will reduce its aircrafts’ emissions by 20 percent.
While the purchase is a small step that won’t substantially reduce the company’s overall carbon footprint, it may help boost demand for alternative fuels, which are currently too expensive to be competitive with conventional jet fuel.
What makes sustainable aviation fuel (SAF) “sustainable” is not necessarily that it produces fewer carbon emissions than conventional jet fuel when it’s burned in an airplane — it’s that it has a smaller carbon footprint when the entire life cycle of the fuel is taken into account. (In addition, many SAFs burn more cleanly, spewing less soot and other pollutants from a plane’s engine.)
SAFs can be made from a number materials, like various plant oils and crops like poplar and switchgrass. Many of the SAFs under development are made from reusable waste products, like used cooking oil, animal fat, municipal solid waste, and corn leaves, stalks, and cobs. Amazon plans to use a blend of jet fuel and SAF derived from animal fats and oils, produced by the fuel company World Energy.
To assess the emissions reductions claimed by Amazon’s SAF, you need to assess every step of its life cycle, compared to that of conventional jet fuel. Jet fuel starts as crude oil in the ground. It has to be pumped, shipped, or sent via pipeline to a refinery, where it is refined and then shipped again to the airport before it’s burned in an engine. The process for Amazon’s SAF, on the other hand, involves growing and delivering food for livestock, feeding and processing the animals, delivering the fat to a refiner and refining it, getting the fuel to the airport, and burning it in the plane. By saying that this fuel will reduce emissions by 20 percent, Amazon and World Energy are essentially claiming that this whole chain of events generates 20 percent fewer emissions than the one for the crude oil the company would have used instead.
Annie Petsonk, international affairs counsel for the Environmental Defense Fund, called Amazon’s purchase an “important baby step” because it could boost demand for sustainable fuels. Today, SAFs are deep in the “valley of death” that frustrates many new energy technologies, she said. Sustainable fuels tend to be more expensive than conventional jet fuel, and investors don’t want to support the innovations that could bring prices down until there’s a bigger market. Some state and federal incentives exist to lower the price, but they still don’t make the price of SAFs competitive with conventional jet fuel, which is especially cheap at present due to the economic slowdown caused by the COVID-19 pandemic.
Petsonk said Amazon’s purchase will help demonstrate that SAFs work and that major companies are willing to pay a premium for them. Her team calculated that switching from conventional jet fuel to the new fuel could reduce the company’s emissions by about 12,000 metric tonnes of CO2. (Achieving this reduction could be jeopardized if production of the fuel has indirect climate impacts, such as causing other companies that use animal fat to switch to palm oil, thereby contributing to deforestation.)
Given that Amazon’s 2019 self-reported carbon footprint was more than 50 million metric tonnes, a 12,000 metric tonne reduction is a drop in the bucket. But at this point, the options to reduce aviation-related emissions are still relatively limited. There are other SAFs that boast larger carbon reductions, but they are still in the early stages of development. The Illinois-based biotech startup LanzaTech is one of the leaders in the space. It produces a form of sustainable ethanol for jet fuel by capturing the emissions from steel mills. Another company, Velocys, is building a plant in the U.K. to supply British Airways with jet fuel made from household waste that would otherwise go to a landfill. Both companies boast a 70 percent reduction in greenhouse gases compared to conventional jet fuel.
Right now SAFs make up just a fraction of a percent of the fuels burned in airplanes, Petsonk said. But with governments around the world excusing the industry from its emissions reduction goals, Amazon’s adoption of sustainable fuel does move the needle, however slightly.