Certifying geologically balanced fuels: pathways, requirements and the case for reforming lower carbon aviation fuels

Geologically Balanced Fuels (GBFs) represent a novel approach to aligning fossil aviation fuel use with net-zero objectives as a complementary strategy to sustainable aviation fuels. By pairing conventional kerosene with geologically stored CO2 units that match its life-cycle emissions, GBFs operationalise a ‘like-for-like’ offsetting principle consistent with Geological Net Zero. For this pairing to be credible, and for GBFs to become a scalable product eventually recognised under compliance schemes, robust certification frameworks are essential. This brief identifies key certification requirements for GBFs and assesses how the CORSIA Lower Carbon Aviation Fuels (LCAFs) framework could evolve into a GBF-aligned product following best practices from certification standards in and beyond the aviation sector. Annex I provides a list of workable point-by-point recommendations on how to amend LCAFs and make them GBF-ready.