Is an airport cap the most effective way to curb noise and carbon emissions?
Three alternative measures that governments should consider instead.
The Dutch government recently announced that it is going ahead with a cap on flights at Amsterdam Schiphol Airport. Flights will be capped at 452,500 per year, 9.5% below 2019 levels and lower than a previous proposal of 460,000.
This may seem like an isolated government policy in the heart of Europe, but it is not.
The Mexican government is reducing capacity at the Mexico City International Airport to 43 operations per hour. In 2022, this was reduced from 62 to 52 operations per hour. This is when a feasibility study of safely operating a maximum of 72 operations per hour had been approved. The reductions last year forced all-cargo airlines to stop operating at the airport.
Across the Pacific, the Australian government has announced plans to introduce flight caps and a curfew at Brisbane Airport. Flight caps would limit the number of arrivals and departures to 45 per hour, fewer than when Brisbane operated a single runway, and ban aircraft movements after 10 p.m. This would mostly impact international departures to destinations like Qatar and Fiji.
Most governments state that their main reasons for the cap are to address noise pollution, but they also cite the need to reduce greenhouse gas emissions, as well as recurring logistical problems at the airports.
While environmental groups support the cuts, among airports, Schiphol is the only one in favour. Unfortunately, most of these government mandates have not followed a consultative process with the airlines operating at these airports. These measures sometimes come from public pressures and at other times political motivations.
Arguably, capping flight movements may not be the most effective approach to reduce noise levels and emissions. For example, the stated goal of the Dutch government is primarily to reduce noise levels by 20% and, ultimately, all emissions from flights operating into Amsterdam. The current flight cap will be easy to circumvent. Capacity can just move across the border to France. After all, Air France has the support of the French govt much more than KLM has of the Dutch.
As a result, the overall emissions will remain the same or even increase if flights move to other hubs like Paris. Moreover, while the airlines and their lobby group, IATA, are up in arms about the potential loss of jobs and the negative economic impact, they are mostly silent on how very valid environmental concerns can be addressed.
Three alternative measures to reduce noise and emissions:
1. Disincentivise operating older aircraft
Growing up in Singapore, I saw only gleaming, brand-new cars on the streets. That is because Singapore has a policy that requires cars to be exported off the island or scrapped once they are older than ten years. To keep running cars that are more than ten years old, a massive fee must be paid to renew the Certificate of Entitlement — which can be close to the price of a new car in some cases.
The principle is simple: incentivise newer cars on the road that pollute less and are quieter, just like new airplanes. If the Dutch government insists that airlines only fly the newest aircraft in their fleet to the country, noise and emissions will automatically go down. Night-time departures can be exclusively designated for the newest and quietest aircraft like the Airbus A220 or Boeing 787.
2. Focus on operational efficiencies and eco-piloting measures
On our weekly sustainable aviation podcast, Maarten Koopmans, the CEO of KLM Cityhopper, recently told me that he operated a flight from Amsterdam to Porto in the shortest possible block-time, despite flying at the slowest airspeed.
While that sounds paradoxical, Maarten and his team could do that by flying the straightest route possible to Porto. In doing this, they deployed the Continuous Descent Approach. This also allowed the airline to reduce emissions by saving fuel.
3. Introduce a "fly more, pay more" principle
Governments can introduce a "fly more, pay more" principle and put the money in a Clean Skies Fund. This could take the form of a small surcharge on flight tickets, starting at less than 10% of the ticket cost.
Think of it as similar to a User Development Fee that some airports charge to fund development and maintenance. In this case, however, frequent fliers will pay progressively more to fund the development and maintenance of the environment. This not only ensures that those who tend to fly a lot are encouraged to fly responsibly, but it also limits the burden on those who fly occasionally or are experiencing the wonders of air travel for the first time.
The funds thus raised should be transparently invested in green technologies or pooled into a sustainability fund. After all, the cost of decarbonising aviation is estimated at up to $5 trillion. This way, frequent fliers can play their part too.
In the future, flights operated by aircraft featuring new technologies would be exempt from these charges, creating an additional incentive for developing greener alternatives.
Ultimately, limiting outcomes like noise footprint and carbon emissions by changing customer behaviour and incentivising airlines will likely be more effective than flight caps.
Shashank Nigam is the CEO of SimpliFlying and the host of the Sustainability In The Air podcast, which is also the title of his upcoming book on sustainable aviation. Connect with him on LinkedIn.