Aviation is the most climate-intensive form of transport. Green fuels, new technology and demand reduction can put us on a path to cleaner flying.

The problem with aviation

Emissions from aviation are a significant contributor to climate change. Airplanes burn fossil fuel which not only releases CO2 emissions but also has strong warming non-CO2 effects due to nitrogen oxides (NOx), vapour trails and cloud formation triggered by the altitude at which aircraft operate.

These non-CO2 effects contribute twice as much to global warming as aircraft CO2 and were responsible for two-thirds of aviation’s climate impact in 2018.

6.3 million EU departing flights (2023)

640 million European passengers (2023)

133 MtCO2 Total of EU emissions (2023)

Aviation growth

Emissions from aviation have been growing faster than any other mode of transport, and have more than doubled between 1990 and 2019. Aviation emissions went from 1.5% of all European emissions in 1990 to 4.7% in 2019. The sector is expected to fully recover from the Covid ‘shock’ as early as 2024.

If unmitigated, aviation emissions could more than double (compared to 2019) by 2050 and in doing so, the sector will consume more than 10% of the remaining carbon budget to stay below 1.5°C of warming.

Subsidising pollution

Aviation remains heavily subsidised, with all parts of the sector – from airports to aircraft to airlines – receiving state support. Aid is being given to airports by local, regional or national authorities – often in breach of EU guidelines concerning state aid. At EU and national level, aid is also granted to aircraft manufacturers.

And airlines are exempt from paying tax on their fuel and VAT on their tickets. These subsidies result in artificially cheap ticket prices, which serve to drive up demand and reduce incentives for more sustainable aviation. Any public money should come with green strings attached.

Clean tech

Cleaner fuels and changes to aircraft design can play an essential role in reducing emissions from flying. Ensuring planes are as efficient as possible and are capable of being powered by alternatives to fossil kerosene, is essential. Both pathways have a role to play, and will require cooperation between industry and regulators.

However, the right type of fuels need to be pursued. Using crop-based biofuels would cause negative effects such as driving deforestation or increasing food prices. Therefore the focus needs to be on Sustainable Aviation Fuels (SAF). These can be advanced biofuels, which are produced using feedstocks which don’t compete with food, or feedstocks derived from renewable electricity, known as e-kerosene.

The EU has introduced a new proposal called ReFuelEU which requires all aircraft departing from an EU airport to uplift a fixed percentage of SAF. This percentage scales up over time and includes additional sub-targets for e-fuels. This initiative aims to boost the supply and demand for sustainable aviation fuels in the EU.

Paying for pollution

The EU has put in place a carbon market for aviation called the Emission Trading System (ETS) which remains one of the few measures in place attempting to address the sector’s soaring emissions. Under the carbon market, airlines must pay for emissions on flights within the European Economic Area (EEA). However, airlines still get more than half of their pollution permits for free and all long-haul flights – which represent the bulk of aviation emissions – are not counted under the carbon market.

Transport & Environment has published a Roadmap to climate neutral aviation in Europe, which outlines the pathway to reducing the emissions of this carbon-intensive industry.