May 17, 2021
Press Releases

The greenhouse gas accounting guidelines mark a milestone in fuel sustainability accounting for airline industry stakeholders.
New Sustainable aviation fuel (SAF) greenhouse gas (GHG) emission accounting and insetting guidelines developed through a collaboration between MIT Center for Transportation & Logistics (MIT CTL) and Smart Freight Centre (SFC), set clear guidelines to facilitate GHG insetting and drive investments in production that will help decarbonize aviation. The guidelines are designed to be flexible enough to drive the long-term value chain collaboration needed to bring real change across the industry. Simultaneously, the rules are stringent enough to ensure real in-sector GHG abatement is achieved through mechanisms that include the prevention of double counting.

Within the last two decades, according to the International Energy Agency, GHG emissions from aviation have increased by 50% (at 2% per year) as passenger flight activity has grown two and a half times. (1) Freight transportation by air has also increased as income and purchase power continue to grow in emerging economies. In 2019 alone, aviation carried 61 million tonnes of freight, worth $6.5 trillion. This represented 1% of global freight by volume but 35% by value. (2)  While jet engine fuel efficiency has also improved substantially over the same period, passenger and freight travel by air still requires high power output and energy-dense fuels. By some estimates aviation fuel, GHG emissions could account for as much as a quarter of the world’s 2050 total carbon budget targets at 1.5C. (3)

Companies, governments, and NGOs worldwide see SAF as one pathway toward reducing airline industry GHG emissions to meet global targets. Most SAF is biomass-derived fuel harvested from waste oils, or organic plant matter, rather than from fossil fuels extracted from underground.(4)  The first SAF demonstration flights happened in 2007 and 2008. (5)  By 2019, more than 180,000 commercial flights had used some form of SAF during the preceding decade. In that same year, there were 3.8 million flights globally, illustrating that there is a long way to go for industry-wide adoption of SAF. (6,7) One factor, the cost of SAF - which can be several times the cost of conventional aviation fuels - has contributed to SAF’s limited use to date. Insetting, or the purchase of GHG emission reductions within an organization’s supply chain, is a tool that aims to spread the cost premium of SAF across the aviation value chain and increase the uptake of SAF. 

The GHG Accounting Guidelines developed by MIT CTL and SFC, commissioned by Shell Aviation, create a framework for GHG insetting in the aviation sector designed to facilitate financing for the production and distribution of SAF. Insetting is a methodology that locates emission reduction activities within a company or an industry’s own supply or value chain. Unlike GHG offsetting that relies on various schemes to allow companies to purchase emissions credits in local or global markets, insetting requires companies to seek emission reduction within their own value chain. The GHG Accounting Guidelines provide a platform for value chain collaboration among stakeholders. They establish a clear set of rules to ensure that these insets drive real in-sector reduction and help prevent emissions reductions from being counted twice within the value chain, known as double counting. 

“Collaborating on projects like these that bring research results to bear on emerging supply chain challenges is one way we engage with industry to foster positive change,” says Chris Caplice, Executive Director of MIT CTL. “It’s exciting to see the publication of this framework and to see our models being put into practice in ways that can influence entire sectors.”

Companies and organizations throughout the aviation supply chain will be able to use the guidelines. From fuel suppliers, air carriers, and logistics service providers (LSPs), to shippers of freight, corporations who use corporate travel, and travel management companies, stakeholders will be able to collaborate on accounting to meet mandated or voluntary emissions goals. The Guidelines create a clear approach for SAF emissions accounting and disclosure that is based on the SFC’s previously developed, Global Logistics Emissions Council (GLEC) Framework. The guidelines are aligned with recognized emissions accounting protocols, including the Greenhouse Gas Protocol, and represent a clear and consistent set of rules that all reporting companies can use.

"Decarbonizing air transportation is critical to achieving an efficient and zero-emissions global logistics sector,” said Dan Smith, Senior Technical Manager, Smart Freight Centre. “Smart Freight Centre is proud to have collaborated with the MIT Center for Transportation & Logistics in developing these guidelines to scale the uptake of SAF and reduce aviation GHG emissions." 

The Sustainable Aviation Fuel Greenhouse Gas Emission Accounting and Insetting Guidelines aim to facilitate collaboration across air transportation value chains, drive the investment necessary to bring SAF production to scale and decarbonize the aviation sector. Companies, organizations, and regulatory bodies are invited to download and utilize the guidelines upon publication in June of 2021. To learn more and be first to receive the publication, visit:


  1. Aviation, International Energy Agency, Retrieved 13 May, 2021 from
  2. Aviation Benefits Beyond Borders Report (September, 2020),  Air Traffic Action Group Retrieved 13 May, 2021 from 
  3. Aviation could consume a quarter of 1.5C carbon budget by 2050 (8 Aug 2016), Carbon Brief, Analysis, Retreived 13 May 2021 from 
  4. SkyNRG Website, Retrieved 05/13/2021 from
  5. Aviation biofuel demonstrations, Wikipedia, Retreived 13 May 2021 from 
  6. Sustainable Aviation Fuels Fact Sheet (May, 2019), International Air Transport Association (IATA), Retrieved, 13 May 2021 from 
  7. Presentation of 2019 Air Transport statistical results (PDF) , International Civil Aviation Organization, Retrieved 13 May 2021, from 
  8. Sinderu, Jon, (Jan 10, 2020) The Promise of Sustainable Aviation Fuel Isn’t for Today, Wall Street Journal, Retrieved from