Will CORSIA Collapse? IATA Warns of Weak Support

The United Nations aviation carbon offset scheme CORSIA is entering its first years of significant offsetting obligations with growing scrutiny, as the International Air Transport Association (IATA) warns that uneven government support and competing regional climate rules could undermine the system many airlines rely on to manage their climate impact.

Global offset scheme at a crossroads

The Carbon Offsetting and Reduction Scheme for International Aviation, known as CORSIA, was created through the International Civil Aviation Organization to limit the climate impact of international flights by requiring airlines to buy carbon credits for emissions above a defined baseline. After a pilot phase from 2021 to 2023 with almost no offsetting costs, the first full compliance phase covering 2024 to 2026 is now underway, marking the moment the system begins to bite financially for carriers.

Publicly available information from ICAO indicates that CORSIA participation remains formally strong. More than 120 states have volunteered to join the first phase, representing close to 80 percent of international aviation activity, with additional countries opting in for 2025 and 2026. Industry groups present this as evidence that the scheme retains broad backing as the only global market based climate tool for aviation.

Beneath that headline, however, the mechanics of the program have changed in ways that significantly limit its reach. States agreed in 2022 to reset CORSIA’s baseline from an average of 2019 and 2020 emissions to a higher level based mainly on 2019 activity, and from 2024 airlines only offset emissions above 85 percent of that 2019 figure. Analysts note that this sharply reduces the share of current emissions that will actually be covered during the 2024 to 2026 period, especially while traffic is still normalizing after the pandemic.

Offsetting demand projections compiled by IATA suggest that, even under traffic growth scenarios, total CORSIA obligations in the first phase will remain modest compared with the sector’s overall emissions. External studies estimate that compliance costs in 2024 and 2025 will account for only a small fraction of typical airline operating expenses, leading some climate campaigners to describe the scheme as having “almost no impact” on carrier finances so far.

IATA pushes back against fragmented regulation

IATA has become one of the most vocal defenders of CORSIA, arguing that a single global framework is preferable to a patchwork of regional carbon markets. The association’s recent fact sheets and policy papers describe CORSIA as the agreed mechanism for managing aviation’s residual emissions and call on governments to avoid overlapping measures that could double charge airlines for the same tonne of carbon.

Much of this concern is directed at Europe, where the EU Emissions Trading System already prices carbon for flights within the European Economic Area and is in the process of tightening coverage and phasing out free allowances for aviation. Policymakers in Brussels are also debating whether to extend the EU ETS to a larger share of long haul departures, a move airline groups warn could conflict with CORSIA and raise costs on routes that are already subject to the UN scheme.

Industry submissions to recent EU consultations, reported by specialist energy and policy outlets, argue that keeping CORSIA as the primary tool for extra European flights would support global consistency and prevent competitive distortions between European and non European hubs. Several airline associations have urged regulators to align future EU rules with CORSIA’s scope and benchmarks rather than building a parallel system.

At the same time, IATA has raised alarms over what it views as insufficient political backing for CORSIA in major markets. In the United States, for example, climate advocacy organizations note that the scheme imposes far lower effective carbon prices than domestic or European cap and trade systems. In this environment, IATA has suggested that sudden spikes in offset prices or tight credit supply could qualify as extraordinary circumstances, language that campaigners interpret as an attempt to shield airlines from higher compliance costs.

Environmental groups question scheme’s credibility

Environmental organizations have long argued that CORSIA’s design is too weak to align aviation with global climate goals. Reports from watchdog groups highlight the limited portion of emissions subject to offsetting because of the high baseline and the exclusion of domestic flights, which account for a substantial share of global aviation activity. They also criticize the reliance on carbon credits, pointing to continuing concerns over the quality and integrity of many offset projects.

Analyses comparing CORSIA to the EU ETS underline the scale of the gap. Estimates published by European climate think tanks suggest that the per tonne cost of compliance under CORSIA is many times lower than under the EU system, largely because only growth above the baseline is priced. One widely cited assessment calculates that if international aviation were fully covered by a carbon market with prices similar to the EU ETS, the sector’s total climate bill would be several times higher than what CORSIA currently imposes.

Civil society groups have also warned that growing dependence on CORSIA could crowd out investment in more durable decarbonization measures such as sustainable aviation fuels and new aircraft technologies. While airlines emphasize that CORSIA is only one pillar of a broader net zero strategy, critics contend that a lenient offset regime risks delaying more costly but necessary changes within the industry.

These tensions have led some campaigners to call on governments to scale back or phase out CORSIA in favor of stronger domestic and regional policies. From this perspective, the danger is not that the scheme collapses outright, but that it persists as a low ambition framework that fails to drive meaningful emissions reductions while being cited as evidence of adequate action.

Risk of “collapse” lies in erosion, not sudden exit

With the first CORSIA offsetting obligations arriving for emissions generated in 2024, attention is turning to whether the system can retain practical relevance as climate policy hardens elsewhere. Aviation emissions have rebounded close to or above pre pandemic levels, and broader climate science assessments reiterate that the sector must deliver steep reductions if global temperature goals are to be met. In that context, a light touch offset scheme faces growing scrutiny.

Rather than an abrupt withdrawal of states, observers describe a more gradual erosion as the likelier risk to CORSIA. One scenario is that leading climate jurisdictions, such as the European Union and potentially parts of North America or Asia, continue building out their own carbon markets, fuel mandates and ticket charges, treating CORSIA as a minimum floor rather than the central instrument. That would leave the UN scheme increasingly marginal for routes covered by stronger regional regimes.

Another risk is reputational. If major airlines lean heavily on CORSIA compliance in their sustainability messaging while independent analyses continue to show aviation emissions rising, public confidence in the scheme could weaken. Consumer facing offset programs have already been scaled back or dropped by some carriers amid questions over project quality, reinforcing skepticism about whether carbon markets alone can credibly neutralize flight emissions.

Under these conditions, CORSIA is unlikely to collapse in the formal sense of being repealed or abandoned by a large bloc of states. Instead, its future role may depend on whether upcoming reviews between now and the start of the second, more mandatory phase from 2027 lead to tighter baselines, stronger credit eligibility rules and closer interaction with regional systems. For now, IATA’s critiques highlight an industry caught between defending a global framework it helped design and adapting to a world that is steadily moving toward higher carbon prices for flying.