Airport CO2 emissions and cities
National governments and industry efforts to align the aviation sector with climate goals are “critically insufficient", analysis by Climate Action Tracker shows. Luckily, they are not the only decision makers with power and influence over aviation’s climate future: cities have a key role to play. As the British Prime Minister said recently about expanding London Heathrow: “I think principally it’s a matter for London and London MPs”.
Local governments have a long history of being more socially and environmentally responsible than their national counterparts. Networks like C40, ICLEI, and the Global and EU Covenant of Mayors are examples of local leaders actively working to advance the climate agenda. These are the places and representatives that come together to push national governments to go further. For example, the 2024 C40 Annual Report, noted that “3 in 4 C40 cities are reducing per capita emissions faster than their respective national governments”.
However, despite their climate leadership aspirations, these networks have surprisingly little to say about aviation emissions. Indeed, a quick search of their online libraries of policy advice and technical reports reveals…
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almost nothing (see: C40, ICLEI, EU CoM).
How can cities that are ardent supporters of reducing GHG emissions be apparently blind to the emissions created by their airports? Is it a subnational version of the exclusion of most aviation emissions from countries’ own carbon targets? Just as nations somehow overlooked international aviation as part of their “economy-wide” plans to implement the Paris Agreement, so-called “global” cities are happy to count the economic gains from international aviation (like tourism, international business connections and trade) yet largely ignore the environmental impacts that these economic activities create.
At the national level, some progress is starting to be made as a few national governments are starting to factor international aviation emissions into their overall carbon budgets. There is clearly more to do here, for example, these plans do not include the full climate impact of aviation – especially non-CO2 (“contrail”) warming effects, and the industry doesn’t seem to have taken any notice.
Fortunately, there are some urban areas that recognise the need to be clear about the climate impacts of aviation in their cities. Policymakers in London and Amsterdam have all strongly rejected calls for further expansions at their major airports. But there are also examples showing how these precarious gains have to be consolidated: A change of government in Barcelona resulted in a shift from nearly a decade of opposition to supporting the expansion of the nearby el Prat airport, giving rise to thousands of protestors supported by national MPs and the Catalan government.
If you’re wondering where to start: read on.
The first step is to count the emissions from a city’s airport or airports. Use the map of the airport tracker and find your local city or region or start typing the city name to pick the airports that are mainly associated. E.g., for Paris, France there are four airports in the tracker.
These four airport cards show a lot of data. We can see, for example, that these Paris airports had 376,808 outbound flights in 2023, generating 18.6 million tonnes of CO2. It’s also clear that this is dominated by passenger flights, and particularly by Charles de Gaulle and Orly airports. However, we can also see that there were also nearly 21,000 freight flights from Paris Charles de Gaulle, and nearly 23,000 private jet flights from Le Bourget airport.
Once we have the headline figures, we can compare these emissions with what is written in local climate plans. If it’s a big city, these may be available via global platforms like C40.
Finally, to understand the tradeoffs that we need to make, it’s key to visualise these data to show how aviation compares to other sectors. In the Airport Tracker we have done this by comparing individual airports to total city emissions, but there are many ways to do this. For example, the 4.5 million tonnes of CO2 per year that would arise from expanding Heathrow Airport is equivalent to running 1.2 coal-fired power stations.
With this data in hand, local communities then have formal and informal ways to make their voices heard and make their representatives accountable.
