Aviation advisory firm IBA’s Sustainability Watch April 2026 puts hard numbers on a question the European Commission will answer in its 2026 EU ETS review: what happens if aviation’s carbon obligation extends beyond intra-EEA flights to all departures from EEA airports.
IBA’s modelling indicates a roughly 109% increase in covered emissions versus today’s scope, which already includes EEA-UK and EEA-Switzerland departures alongside intra-EEA flights. Long-haul departures from EEA airports to the rest of the world remain exempt under the stop-the-clock derogation, currently extended to end-2026, and instead fall under CORSIA. Letting that derogation expire is the headline option in the Commission’s evidence-gathering.
The cost gap is what makes the policy choice load-bearing. IBA puts the effective EU ETS compliance cost per tonne of long-haul CO2 at around 35x the equivalent CORSIA cost, once CORSIA’s 2026 sectoral growth factor — which obliges carriers to offset only a small fraction of emissions — is applied. That is a per-tonne-emitted ratio, not a raw EUA-versus-credit price ratio, and it will compress sharply once CORSIA Phase 2 lifts the offset share in 2027 onward. Carriers with disproportionate long-haul exposure from EEA hubs would absorb most of the near-term differential.
“Carbon leakage is a risk with EU ETS expansion, where this strict new policy could incentivise airlines to diversify their hubs.”
That line captures the second-order question the Commission will need to answer. IBA’s per-carrier modelling, contributed to by Senior Aviation Analyst Ruchika Kulkarni and Senior Analyst (Sustainable Aviation) Archie Brown, places KLM at the top of the league table with an incremental fuel-cost impact of roughly 12% — that is, the modelled additional ETS allowance cost expressed against fuel spend, not the share of KLM’s fuel volume newly in scope. Lufthansa and Air France sit close behind, reflecting the long-haul intensity of Amsterdam, Frankfurt and Paris CDG. Non-EEA carriers operating into Europe, such as Emirates and United, would see roughly a 2-3% incremental fuel-cost impact, a gap that is small in percentage terms but the mechanism IBA flags for hub diversification.
For SAF, the expansion changes the incentive math at the long-haul end of the network where SAF blending economics are weakest. ReFuelEU’s blending obligation applies to fuel uplifted at Union airports above the 800,000-passenger or 100,000-tonne-freight thresholds, irrespective of destination, so a long-haul departure from a major EEA hub already carries a SAF cost the carrier cannot avoid by routing. Extending the ETS to that same departure compounds the carbon cost, narrowing the case for tankering at non-EEA hubs. The 35x near-term per-tonne cost differential does not close the SAF premium — HEFA still sits at roughly two to three times conventional jet on volume terms and e-SAF further out — but it narrows the residual gap.
Watch the Commission’s evidence-gathering window. The 2026 ETS review process is now collecting industry input on the expansion options, with a formal proposal expected later in the policy cycle. IBA’s report is one of the first carrier-level quantifications of the leakage risk, which is the lever airlines and their associations will lean on hardest in the consultation. The cleanest single tell will be whether the Commission proposes a flanking mechanism — a CORSIA-style offset facility, a carbon border adjustment for aviation, or a partial scope option — alongside the headline expansion.
Source: IBA
