Aviation
Aviation is a major producer of greenhouse gases emissions, yet it is not reducing its climate impacts at the pace needed…
What’s the problem?
The aviation industry contributes 3% of international carbon dioxide emissions – roughly the same as Germany or Japan’s annual total.
Action to reduce aviation pollution has been drastically inadequate to date. With existing policies and growth projections, air travel emissions are set to double to as high as 1,700 million tonnes by 2050.
The technologies needed to reduce the majority of aviation emissions already exist. These are derived from renewable energy, either stored in a battery or used to produce renewable hydrogen that powers a fuel cell or is subsequently used to create synthetic e-fuels.
But these solutions need to develop and scale faster to set aviation on track. Meanwhile, policy continues to channel limited resources to alternative fuels like biofuels, that may have high associated emissions and put nature and food security at risk, and may even release more emissions than conventional fuels.
International aviation's projected emissions pathway
Data from Climate Action Tracker
What we do
The SASHA Coalition members include front-running companies developing the most sustainable aviation energy solutions.
As a coalition we bring these companies’ voices to EU and UK politicians and policymakers to demonstrate what policy is needed to support the development and commercialisation of their solutions at the necessary speed and scale, and accelerate the transition of aviation to a sustainable future.
Our members and knowledge partners
Decarbonising EU aviation
How big is the problem?
Roughly 4% of EU carbon emissions come from aviation. Its total climate impacts will be much higher when non-CO2 emissions are accounted for, which may be twice as great as CO2 emissions.
What policy is in place?
The EU’s system for regulating aviation’s climate impacts has two central pillars: ReFuelEU Aviation and the EU emissions trading system (ETS).
ReFuelEU Aviation
ReFuelEU Aviation came into force in 2025 and is designed to boost demand for alternative aviation fuels.
It obliges fuel suppliers to include a certain proportion of alternative fuels in the fuel mix, starting at 2% and increasing gradually to 70% in 2050. It includes a sub-mandate for synthetic fuels that comes into effect at 1.2% in 2030.
EU emissions trading system (ETS)
The EU ETS was extended to cover aviation in 2012, requiring airlines to buy allowances to cover their CO2 emissions.
Each year the number of available allowances incrementally decreases, meaning the industry is incentivised to decarbonise over time or face increasing costs. Member States are obliged to re-invest the revenues generated from the ETS into climate action.
However, the scope only covers flights within Europe and not flights between European and non-European airports, leaving around 60% of CO2 emissions unpriced. Furthermore, non-CO2 emissions and climate impacts, namely contrails, are not covered in the ETS. These may account for up to two thirds of aviation’s total climate damage.
Airlines have also benefited from a huge amount of free allowances totalling €8bn between 2012-2023.
What is the SASHA Coalition working on?
Explore all our work on EU aviation
Decarbonising UK aviation
How big is the problem?
Aviation is responsible for roughly 7% of the UK’s total greenhouse gas emissions, producing an annual 29.6 million tonnes. On the current trajectory, this figure is projected to rise to 38 million tonnes by 2050 — 80% of the UK’s expected CO2 emissions.
What policy is in place?
The UK emissions trading scheme (ETS)
Aviation’s climate impact has been regulated by the UK emissions trading scheme (ETS) since 2021, when it formally separated from the EU ETS (where UK carriers have fallen in scope since 2012). Like in the EU, this puts a price on all in-scope emissions and incentivises reductions by gradually lowering the cap of available allowances.
Similarly to the EU ETS, the UK ETS covers neither emissions from international flights outside of Europe nor non-CO2 climate impacts.
The SAF Mandate
The SAF Mandate obliges fuel suppliers to include increasing quantities of alternative aviation fuel in the fuel mix. The required amount started at 2% in 2025 when it was introduced and will increase to 22% in 2040.
It includes a sub-target for synthetic, or power-to-liquid (PtL), fuels that increases from 0.2% in 2028 to 3.5% in 2040. The SAF Mandate also has a cap for how much HEFA biofuels can contribute to the annual targets.
The Revenue Certainty Mechanism
Complementary to the SAF Mandate is the planned Revenue Certainty Mechanism, a government-backed financial instrument which will guarantee a fixed price for producers of alternative aviation fuels. This intends to reduce project risks, easing developers’ access to private investment.
