United Airlines and United Airlines Ventures (UAV) announced an investment in and commercial agreement with Dimensional Energy, another step forward, according to the announcement, to reach United’s 100% green net zero commitment by 2050, without the use of traditional carbon offsets. Dimensional Energy’s technology removes the need for fossil fuels, converting carbon dioxide and water into usable ingredients for the Fischer-Tropsch process — a nearly 100-year-old proven technology used to produce fuels from coal or methane. While facilities around the world continue to use Fischer-Tropsch to produce fossil fuels, Dimensional will be one of the first to use it to produce sustainable aviation fuels (SAF). Under the commercial agreement, United has agreed to purchase at least 300 million gallons of SAF over 20 years from Dimensional. United’s SAF agreements, according to the company, represent the largest volume of SAF of any airline over the next 20 years, based on publicly announced agreements. Michael Leskinen, president of UAV, said that “sometimes you have to look to the past to solve new problems,” and the company recognizes that decarbonizing air travel is going to require combining proven technologies, such as Fischer-Tropsch, with the latest advances in science and engineering.