A CORSIA Lower Carbon Aviation Fuel (LCAF) is defined in Annex 16 Vol IV as a "A fossil-based aviation fuel that  meets the CORSIA  Sustainability Criteria under this Volume." LCAF can serve as a complementary measure alongside Sustainable Aviation Fuels (SAF) in helping to reduce aviation greenhouse gas (GHG) lifecycle emissions. The LTAG report includes a quantification of the potential contributions from LCAF towards the ICAO long term aspirational goal for international aviation (LTAG)..

An LCAF may be certified as a CORSIA eligible fuel if it meets the CORSIA Sustainability Criteria, including a 10% reduction in lifecycle emissions compared to the aviation fuel baseline of 89 gCO2e/MJ. For example, five billion liters of LCAF at 80 gCO2e/MJ could provide the equivalent GHG emissions reduction of about one billion liters of SAF at 45 gCO2e/MJ.

Details on the CORSIA eligibility and life cycle emissions of LCAF are provided in

LCAF technologies

A variety of technologies and processes can be used to produce CORSIA LCAF, such as carbon capture and sequestration (CCS), renewable and low carbon intensity hydrogen, and renewable and low carbon intensity electricity. Further, LCAF producers and their crude suppliers can use additional mitigation measures, such as methane emission management (venting, flaring and fugitives - VFF) and use of newly developed crudes. 

More details on these technologies are provided in the following references:

• Update on LCAF technologies (ICAO CAEP, April/2023) 
  

• Lower Carbon Aviation Fuels: contributing to the energy transition. ICAO Environmental Report 2022.
  

• Aviation Climate Policy &Lower Carbon Aviation Fuel, ICAO Stocktaking 2019.
  

LCAF sustainability

LCAF sustainability criteria are defined in the ICAO document "CORSIA Sustainability Criteria for CORSIA Eligible Fuels". More specifically, Chapter 3 of this document defines sustainability criteria applicable to batches of CORSIA LCAF produced on or after 1 January 2024 (e.g. after the CORSIA Pilot Phase). These LCAF sustainability criteria cover carbon emissions, environmental and socio-economical aspects.

LCAF life cycle emissions

Under CORSIA, the life cycle emissions of LCAF needs to be obtained with the use of the methodologies defined in Chapter 7 of the ICAO document "CORSIA Methodology For Calculating Actual Life Cycle Emissions Values".