A new study by green group Transport & Environment (T&E) into European airline emissions in 2023 found that, for the third year in a row, Ryanair emitted more carbon than other airlines and had its most polluting year yet.
Lufthansa and British Airways were the second and third biggest polluters last year, but remained below their pre-Covid levels of flying. Meanwhile, budget airlines Ryanair and Wizz Air polluted more than ever last year, far past their peak in 2019. Ryanair emitted 15 Mt of CO2 in 2023, equivalent to that of 7 million petrol cars in a year and 23% higher than pre-Covid, while Wizz Air’s emissions grew by 40%.
In 2023, one flight out of four in Europe was operated by one of the three main low-cost carriers (easyJet, Ryanair, Wizz Air), the analysis shows. In 2019, it was one out of five, showing that budget airlines are growing their market share in Europe. On the other hand, legacy carriers including Air France, Lufthansa, KLM and British Airways, have lost 2.8 pp market share since Covid.
Despite low-cost growth, legacy carriers and selected third country carriers are still responsible for the bulk of European aviation emissions (42.2%) because they fly long-haul. In fact, the study finds that 20 airlines (European legacy carriers and the biggest third country carriers) are responsible for a larger share of emissions than that of over 400 airlines flying from Europe combined.

Moreover, the study found that Air France and Lufthansa only paid for 7% and 16% of their emissions, respectively, because of the “limited scope of the European carbon markets and the free allowances given to airlines”. Without these exemptions, Lufthansa would have paid over €800 million for its CO2 emissions last year, but only paid €130 million. When broken down per tonne of CO2, Lufthansa paid €13 and Air France €5.
Budget airlines, which have to pay more because they fly more intra-European routes, also paid for less than half of their emissions, T&E says. Overall, as much as 78% of aviation’s CO2 emissions were not priced last year.
“Flying is far too cheap. Whether we are talking of legacy carriers or budget airlines, the aviation sector is not paying enough for its carbon emissions. Over ten years after the carbon market was introduced for aviation, the system still falls short when it comes to incentivising a shift away from fossil flying”, said Jo Dardenne, aviation director at T&E. “This absurd situation where a passenger pays more for their coffee at the airport than some airlines pay for their emissions must come to an end.”

In 2023, Europe’s most frequented route was London-Dublin with approximately 44 flights a day (one-way), the study found. On the second busiest route, London-Amsterdam Schiphol, which has a direct four-hour train alternative, more than 43 flights departed every day last year. The five most polluting routes departing from Europe were all intercontinental, meaning they are not priced under the EU, Swiss or UK’s carbon market, which only applies to flights within Europe. As a result, no airline had to pay for its emissions on the most polluting route departing from Europe – the London-Dubai leg – even though it accounted for 2.3 Mt of CO2.