Microsoft, United partner with RSB, SABA, and Air bp on the first sustainable aviation fuels book and claim pilot

November 16, 2021 — Microsoft and United Airlines, in partnership with RSB, Air bp, and the Sustainable Aviation Buyers Alliance (SABA) intends to pilot the world’s first book and claim system for sustainable aviation fuels (SAF). This system will enable companies to invest in SAF, which can count towards their net zero emission goals, without having to own or use the physical volume of fuel. A robust book and claim system is a key tool to support the widespread uptake of SAF, which is critical to decarbonizing aviation.  

In this pilot, which is currently being worked on by the various parties, Air bp is to supply 7,000 gallons (26,500 litres) of waste-based SAF to United at UK airports that achieves approximately an 80% reduction of lifecycle GHG emissions in comparison to the fossil fuel it replaces. The associated emissions reductions will be claimed by Microsoft, and the transaction will be registered with RSB. SABA, a joint initiative of Environmental Defense Fund (EDF) and RMI, is providing guidance on how to simultaneously address UK policy requirements and recognize the emissions benefits for a voluntary corporate purchase. This experience will inform SABA’s work to develop a digital book and claim registry for SAF, in collaboration with RSB. 

United and Microsoft have both previously invested in SAF – United has worked with its customers to purchase SAF through its Eco-Skies Alliance, and Microsoft has previously partnered with Alaska Airlines and SkyNRG to purchase SAF – but this pilot is the first time that SAF environmental attributes have been transferred using RSB’s book and claim guidance, independently of the physical supply chain. The book and claim system’s robust traceability and transparency requirements ensure that the environmental benefit of SAF is verified and not double claimed. 

Microsoft’s commitment to advancing a robust book and claim system to invest in SAF, in addition to prioritizing the most sustainable certified SAF from RSB-certified supply chains, is laudable. It sends a clear signal to the SAF industry that corporate climate leaders want to invest in SAF that prioritizes sustainability through a transparent and credible system. 

RSB is developing the book and claim system with expert input across the aviation value chain. Stakeholders represent airlines, fuel producers, corporate end customers, civil society, academia and more. Feedback on the project will be key to ensure credibility and broad support of the book and claim system going forward. 

As Microsoft announced its participation, Carbon Program Manager Elizabeth Willmott had this to say, Sustainable aviation fuel is a critical strategy to decarbonize aviation, and a healthy market for SAF in the future depends on clear carbon accounting rules today. We need to ensure transparency and credibility for any environmental claims for sustainable aviation fuel purchases. This pilot offers a promising opportunity to do just that.”  

United’s participation is showcasing how airlines can help to bring meaningful benefits, in the form of credible and traceable emissions reductions, to their corporate customers. Lauren Riley, United’s managing director of global environmental affairs and sustainability welcomed the collaboration, saying, “Successful decarbonization partnerships require transparency and trust. With this project, we are making transparency and trust easier, enabling future partnerships that will help create a sustainable future for commercial aviation.” 

Elena Schmidt, RSB’s executive director, who has been driving the development of RSB’s approach to book & claim with the RSB team for several years added, “I am absolutely thrilled to welcome Microsoft and United’s participation on this exciting pilot project with Air bp. Their participation in the project really highlights how this innovative approach can add real value for companies that are setting ambitious goals on decarbonisation – taking the pilot into the real world. Microsoft’s commitment to sourcing RSB-certified fuel is a fantastic example of how companies can use their buying power to drive positive impacts, even outside their own direct supply chains!”  

Kelley Kizzier, Vice President of Global Climate for Environmental Defense Fund, which co-leads SABA, noted, “Reducing greenhouse gas emissions from air travel is a considerable challenge for companies and for the world. To face it, we need companies and airlines to show leadership, model transparency, and hold themselves to high sustainability standards. The pilot that Microsoft and United Airlines are undertaking is an example of the leadership we need to achieve widespread adoption of high-integrity SAF. The Sustainable Aviation Buyers Alliance looks forward to applying the lessons learned from this pilot to the development of an electronic book and claim registry, alongside RSB, so that more air transport customers can benefit.”  

Bryan Fisher, managing director of RMI’s Climate-Aligned Industries program shares, “This book and claim system is a game changer for the SAF market. Just like early solar and wind electricity renewable electricity credits, virtual ownership of SAF’s environmental attributes can accelerate the technology by unlocking new payers and their resources. That’s why SABA has prioritized participation in this pilot, and will apply what we learn to the creation of a digital registry for SAF certificates.  



The Roundtable on Sustainable Biomaterials (RSB) is an international, multi-stakeholder, independent organisation that supports the just and sustainable transition to a global bio-based and circular economy through sustainability solutions, certification, innovation and collaborative partnerships. 

With credible solutions, global expertise, partners across the spectrum from government to industry and NGOs, and an extremely robust approach to sustainability, RSB is the partner of choice for the bioeconomy as it seeks to combat climate change while also ensuring social development and environmental protection. 

Further information can be found on 

About SABA 

The Sustainable Aviation Buyers Alliance (SABA) is an alliance of aviation customers, airlines, and environmental organizations dedicated to accelerating the path to net-zero aviation, driving investment in and adoption of high-integrity sustainable aviation fuel (SAF), and supporting companies in achieving their climate goals. SABA’s founding companies include Bank of America, Boeing, Boston Consulting Group, Deloitte, JPMorgan Chase, McKinsey & Company, Meta, Microsoft, Netflix and Salesforce. SABA’s Founding Aviators group includes Alaska Airlines, Amazon Air, JetBlue and United Airlines. SABA is managed by Environmental Defense Fund (EDF) and RMI, with expert support from ENGIE Impact serving as SABA’s Secretariat. 



About RMI 

RMI is an independent nonprofit founded in 1982 that transforms global energy systems through market-driven solutions to align with a 1.5°C future and secure a clean, prosperous, zero-carbon future for all. We work in the world’s most critical geographies and engage businesses, policymakers, communities, and NGOs to identify and scale energy system interventions that will cut greenhouse gas emissions at least 50 percent by 2030. RMI has offices in Basalt and Boulder, Colorado; New York City; Oakland, California; Washington, D.C.; and Beijing.  

More information on RMI can be found at or follow us on Twitter @RockyMtnInst. 

About EDF 

One of the world’s leading international nonprofit organizations, Environmental Defense Fund ( creates transformational solutions to the most serious environmental problems. To do so, EDF links science, economics, law, and innovative private-sector partnerships. With more than 2.5 million members and offices in the United States, China, Mexico, Indonesia and the European Union, EDF’s scientists, economists, attorneys and policy experts are working in 28 countries to turn our solutions into action. Connect with us on Twitter @EnvDefenseFund. 

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