A new study from the thinktank ODI Global, in collaboration with Transport and Environment (T&E), has identified the world's most polluting airports by analyzing climate and air quality impacts across 1,300 hubs. The findings place three European airports—London Heathrow, Paris Charles de Gaulle, and Frankfurt—among the top ten, despite their stated commitments to net-zero emissions by 2050.
Using 2023 data from the International Council on Clean Transportation, the research shows that if the aviation sector were a country, it would rank as the fifth-largest emitter globally. Just 100 airports account for roughly two-thirds of total CO2 emissions from passenger flights, while European airports collectively produce more emissions than those in Latin America, the Middle East, and Africa combined.
Europe's airports in the spotlight
Dubai International Airport tops the list with 23.2 million tonnes of CO2, followed by London Heathrow at 21 million tonnes and Los Angeles at 18.8 million tonnes. Together, these three hubs emit three times as much CO2 as the entire city of Paris—excluding aviation emissions. Seoul Incheon, New York's John F. Kennedy, Hong Kong, Paris Charles de Gaulle, and Frankfurt round out the top ten.
The presence of Charles de Gaulle and Frankfurt highlights a broader European challenge: major hubs in France and Germany are among the worst offenders, even as the European Union pushes for stricter climate targets. The UK, though no longer an EU member, remains a key part of the continent's aviation network.
Aviation's growing footprint
Denise Auclair of T&E argues that the sector remains “off-track” to meeting net-zero goals. “Allowing a fossil-dependent sector to continue expanding by increasing airport capacity only reinforces aviation’s greatest vulnerability,” she says. “In the majority of European capitals and regions, the economic case for airport expansion is no longer supported by the latest evidence. It’s high time to prioritise our energy independence and citizens’ health.”
Sam Pickard, a research associate at ODI Global, notes that while many sectors have reduced emissions since the 2015 Paris Agreement, aviation's footprint has risen steadily. “On top of that, we still regularly hear about airport expansion plans that ignore the sector’s outlier status when it comes to emissions,” he adds. “This should no longer be buried under the rug with half-baked promises of ramping up expensive so-called Sustainable Aviation Fuels or weak offset mechanisms. A genuine strategy and roadmap that includes demand management are sorely needed.”
London Heathrow responded by stating it has “a clear plan to hit net zero and expansion plans need to meet the UK’s legally binding targets on carbon, air quality and noise set out by the government.”
The findings come amid broader debates about airport expansion across Europe, including plans in Brussels and elsewhere. Critics argue that such projects lock in fossil fuel dependence for decades, undermining climate goals. Meanwhile, initiatives like Spain's climate shelters offer alternative models for adapting to a warming world without expanding aviation infrastructure.
The study underscores a tension between economic growth and environmental commitments. As European policymakers weigh new airport capacity, the data suggests that demand management—not just technological fixes—must be part of the solution. Without it, the continent's airports will continue to punch above their weight in emissions, even as they promise a greener future.
