CORSIA: India Eyes 1% SAF Blend as 2027 Offsetting Phase Nears

Why international aviation has a shared system

An international flight departs in one country and arrives in another. A common system helps airlines account for emissions across such services without every route having a completely different carbon-offset framework. The International Civil Aviation Organization, or ICAO, is the United Nations agency responsible for international civil aviation standards. Its member states adopted CORSIA in 2016 as part of a wider set of climate measures. More efficient aircraft, better operations and lower-life-cycle-emission fuels remain important; offsets are intended to complement those changes, not replace them.

CORSIA concerns carbon dioxide emissions from international aviation. It does not cover domestic flights merely because an airline also flies overseas. Within the international system, reporting emissions and having an offsetting obligation are different matters. Monitoring, reporting and verification began in 2019 for qualifying operators, including those from states not yet participating in offsetting. Consequently, 2027 is not the first year in which airlines must understand and record their emissions. It marks an expansion of the offsetting phase for countries such as India.

Phases and routes determine coverage

The pilot phase ran from 2021 to 2023, followed by the first phase from 2024 to 2026. State participation in offsetting during these phases is voluntary. The second phase runs from 2027 to 2035 and uses international aviation activity criteria to determine participation. Exemptions remain for specified smaller aviation markets, least developed countries, small island developing states and landlocked developing countries, unless they volunteer. Calling it the “mandatory phase” therefore does not mean every flight between all member states automatically has an offsetting obligation.

Coverage also depends on the route: both endpoint states must be included for that route's emissions to enter offsetting requirements. This treats operators on the same covered route alike, rather than deciding coverage solely from an airline's nationality. A route with an exempt endpoint can have a different position from one linking two participating states. Monitoring and reporting may still apply even where offsetting does not. These distinctions matter when an airline works out which emissions belong in its compliance calculation, rather than simply adding every flight together.

The baseline is not an airline's physical emissions ceiling

For 2024–2035, the scheme's baseline is 85 per cent of the relevant international aviation emissions recorded in 2019. This does not require each airline to reduce its own actual emissions to that level. Instead, the baseline helps determine the sector's offsetting requirement and the growth factor used to allocate obligations. Under the current resolution, the calculation remains wholly sector-based through 2032. An operator's covered emissions are multiplied by the applicable factor; this is not simply its own growth above a personal 2019 limit.

The authority then accounts for eligible fuel-related reductions when determining the operator's final obligation. Airlines report annually, while offsetting obligations are reconciled in three-year compliance periods. That separates the year in which emissions occur from the later completion of the compliance process. A new phase begins in January, but the related purchases, cancellations and verification do not all happen on its first day. Airlines need reliable records throughout the period, not a last-minute calculation based only on fuel bought near a deadline.

Reliable measurement comes before a credible claim

Monitoring, reporting and verification means collecting emissions information, submitting it in a defined form and having it checked. An operator's monitoring plan sets out its methods and supporting procedures. Records must be sufficiently consistent for an independent verifier to assess the information, calculations and controls behind the report. A claim about lower emissions is therefore not accepted merely because an airline advertises a cleaner fuel or buys a certificate. The evidence must connect the operation, fuel-related claim and compliance record in a way that can be examined.

How sustainable fuel changes the calculation

SAF is renewable or waste-derived aviation fuel that meets the applicable sustainability criteria. CORSIA also recognises a separate category of eligible lower-carbon fossil-based aviation fuel. Neither label means the aircraft stops emitting carbon dioxide when it burns fuel. The comparison instead considers emissions over the fuel's life cycle. This includes obtaining and processing the raw material, making and transporting the fuel, and burning it in the engine. Land-use effects can also change the result, so feedstock origin and production method matter.

An eligible fuel's verified life-cycle performance can reduce an airline's offsetting requirement, but the claim needs the required records and sustainability certification. Fuel producers must be certified under a certification scheme approved for CORSIA. A blending percentage alone does not establish the size of the emissions benefit. One per cent of fuel supplied and one per cent less emissions are different measurements. The reduction depends on the fuel's emissions performance and the amount properly accounted for, not simply a “sustainable” description on a delivery document.

Buying a credit is not the final compliance step

For the remaining obligation, the airline must use eligible emissions units from programmes approved for CORSIA. These units represent recognised reductions, avoidance or removals elsewhere. The airline must cancel the required units: permanently retire them so they cannot be used again. Merely purchasing credits and continuing to hold them does not complete that step. Programme approval also has a defined scope and compliance period. A credit sold on a voluntary market is not automatically acceptable for any CORSIA obligation.

Credit integrity depends on what happens behind the registry entry. Reductions should be additional, meaning they exceed what would otherwise occur, rather than rewarding an unchanged business-as-usual outcome. Credible baselines, independent verification, traceability and measures against reversal or displaced emissions are also important. Double counting must be prevented, including cases where the same reduction is claimed by both an airline and a host country. These requirements explain why a cheap credit is not necessarily an eligible or environmentally dependable one. The accounting needs a real underlying climate benefit.

India's policy task goes beyond announcing a percentage

India had already announced indicative SAF blending targets: one per cent in 2027 and two per cent in 2028. The target rises to five per cent in 2030. An amendment notified on 17 April 2026 brought specified SAF-blended and co-processed aviation fuel within the Aviation Turbine Fuel control framework. This was an enabling regulatory step, not proof that the comprehensive October policy had been finalised. Fuel quality requirements and CORSIA sustainability requirements are also separate tests. Meeting a technical specification does not by itself establish eligibility for a carbon-accounting benefit.

The October report described industry concerns about pricing, production, export rules and predictable demand for domestic fuel. Airlines need dependable supply, while producers need confidence that buyers will take their output. Rohit Kumar, secretary general of the SAF Association, estimated annual offsetting needs of around five million tonnes. At assumed prices of $10–15 per credit, his projected annual bill was $50–75 million. That is an estimate, not an invoice or a guaranteed charge. Actual costs depend on covered emissions, eligible fuel use, the final obligation and the price of acceptable units.

Conclusion

India's reported SAF requirement and CORSIA address connected but different parts of aviation's climate challenge. Blending policy concerns the fuel supplied; CORSIA concerns covered emissions, verified reductions and the retirement of eligible credits. Neither mechanism makes a flight physically emission-free, and carbon dioxide accounting does not resolve every non-carbon-dioxide climate effect of aviation. The practical test is whether fuel supply, evidence and compliance rules work together. A claimed reduction must be traceable to a valid environmental benefit.