A high-integrity route for CORSIA: integrating geologically balanced fuels

Working paper

• Criticism of the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) largely stems from its reliance on downstream offsetting markets that lie outside its direct oversight.
• Geologically Balanced Fuels (GBFs) – kerosene bundled with geological CO2 storage units and accounted for at the point of fuel supply – could strengthen the integrity and effectiveness of CORSIA.
• GBFs can be treated as either a distinct CORSIA Eligible Fuel category, or as an offsetting instrument under the Eligible Emissions Units framework. We argue that the GBF product is most complementary and additional to existing approaches when treated as an eligible fuel.
• GBFs are intended to complement, rather than replace, Sustainable Aviation Fuels and Lower Carbon Aviation Fuels.
• Although the current CORSIA framework does not yet accommodate GBFs, it already contains important institutional building blocks, including recognition of fossil-derived eligible fuels and governance rules for carbon capture and storage projects, including a Reserve Inventory Account.
• Integrating GBFs into CORSIA would require three core amendments: legal recognition of GBFs, a methodology for accounting for GBFs, and GBF-specific sustainability criteria.
• The most important technical reform would fall within the CORSIA Methodology for Calculating Actual Life Cycle Emissions Values, through the addition of a GBF-specific chapter covering applicability and underlying fuel value, allocation of qualifying geological storage to a GBF batch, calculation of the GBF actual value, exclusivity and non-overlap, and Sustainability Certification Scheme verification of the GBF methodology.

Authors: Jiang, K; Jenkins, S; Brazzola, N; Allen, M

• Publication status: Published
• Publisher: Oxford Net Zero, University of Oxford
• Pages: 1-23
• Series: Oxford Net Zero Policy Briefing
• Place of publication: Oxford
• Publication date: 2026-08-01
• DOI: 10.5287/ora-2apoodekw
• Language: English