Menu Close
Really deep cuts in aircraft emissions are still a distant prospect. Joakim Lloyd Raboff/

The planned aviation emissions rules will just delay the heavy lifting until later

There appeared to be some rare good news this week for reducing greenhouse gas emissions from aircraft.

At a meeting in Montreal, the environment committee of the United Nations’ International Civil Aviation Organization (ICAO) unanimously recommended that new CO₂ emissions standard be applied to new aircraft designs from 2020, and to new deliveries of current in-production aircraft types from 2023. Aircraft that do not meet the standards would cease production by 2028.

The recommendation still needs to be adopted by ICAO’S 36-member governing council, although it is likely to back them unanimously. But will the new standards make a genuine difference to the previously unregulated emissions from air travel?

Flight plan

The committee reportedly considered a set of ten “stringency options”, which would curb emissions from large aircraft by amounts ranging from 20% to just over 40%.

The issue in contention was which option to choose for aircraft that are already in production. In contrast, yet-to-be-designed aircraft were less controversial; most ICAO members were in favour of stringent standards for designs that don’t yet exist (future generations always seem to wear the cost of climate change).

The option chosen, and the recommended time frames for implementation, suggest that the imposition on manufacturers may be minimal.

The proposal will require carbon dioxide emissions from new aircraft to be cut by just 4% over 12 years, when market forces alone are predicted to deliver more than a 10% efficiency gain in the same time frame.

Welcome news?

Airlines, industry groups and governments have all welcomed the recommendations. A senior White House official said that the United States had “pushed hard for a strong standard” and that the government is “very pleased with the result”. A fact sheet issued by the White House said:

When fully implemented, the standards are expected to reduce carbon emissions more than 650 million tons between 2020 and 2040, equivalent to removing over 140 million cars from the road for a year.

The US government added that the ICAO announcement:

…follows closely on the heels of the Paris Climate Agreement reached last December and demonstrates the international [aviation] community’s continued commitment to take action on climate change…

The only problem is that it doesn’t. In reviewing how the Paris climate negotiations affected international aviation, Geneva-based industry lobby group the Air Transport Action Group (ATAG) noted that:

There ended up being no direct reference to international aviation in the final [Paris climate agreement] text, we expect partially because there were much ‘bigger’ issues to concentrate on and also because ICAO and the industry remain fully focused on the aviation climate challenge and are working hard to deliver solutions under the ICAO mandate.

This is a curious claim to make – especially given that legally binding national emissions targets were not on the table in Paris, and that countries’ climate pledges were announced before the climate summit began and were not up for renegotiation.

It’s mostly curious, though, because the White House estimates that commercial aircraft account for 11% of global transportation emissions and that, without more action, these emissions may grow by almost half.

That’s a conservative estimate. The Intergovernmental Panel on Climate Change calculates that aviation accounts for up to 8% of total global emissions (if air travel were a country it would be ranked 7th for emissions, between Germany and South Korea), and air travel is growing by 4-5% a year.

The United Nations estimates that without switching to alternative fuels, total aviation emissions will be anywhere between 290% and 667% above 2006 levels by 2050.

Easy to effect, but ineffective

What’s more, estimates vary widely for the emissions reductions that will be delivered by the new standards. The White House calculates that the new rules would cut CO₂ emissions by 650 million tonnes between 2020 and 2040.

But the European think tank Transport and Environment claims that the true emissions reduction over that period would be closer to 300 million tonnes, while another research group, the International Council on Clean Transportation, puts the figure even lower.

National governments will support the new aviation standard, just as they will support the development of a market-based mechanism, almost certainly in the form of an emissions trading scheme.

Both are options are easier and more palatable than a straightforward carbon tax on airline tickets. But both are likely to be less effective in cutting the carbon footprint of air travel.

Want to write?

Write an article and join a growing community of more than 175,000 academics and researchers from 4,814 institutions.

Register now