The aviation industry is a major contributor to the world’s carbon emission and greenhouse gas problem, generating 2% of the world’s carbon dioxide emissions and estimated to account for 3% by 2050. The UK’s aviation sector, for example, was responsible for 34 million tonnes of CO2 emissions in 2012, a figure forecast to rise to 43.5 million tonnes by 2030 [1].

The huge volume of commercial aviation activity, the long distances we now travel, the massive amount of fuel burned to power the equipment, the release of emissions directly into higher levels of the atmosphere, the ever-growing demand for capacity – this all adds up to a very knotty problem for the industry to address. How can we better balance the need to accommodate unprecedented growth in demand with the environmental imperative to fly far less than we already do?

There are a number of methods currently in use, of varying levels of effectiveness.

What are we doing?

On the passenger level, carbon offset schemes have not necessarily been successful, with most airlines yet to offer them and some of those that do reporting passenger take-up rates of only 10% [2]. This may be due to terminology being unclear, people not having enough information about where their cash goes or what it is used for, or preferring not to part with extra money when they are already paying for (potentially costly) airfares, among other possibilities. Whatever the reason, a participation rate of 10% is unlikely to make a significant dent in the problem.

Moving a level higher in the structure to the metal, while manufacturers are constantly striving to improve the technology to make it smarter and ever more fuel efficient, the growth in demand far outstrips our ability to shrink the associated environmental damage.

The technological improvements that are being made, while incredibly impressive and exciting, are not yet sufficient to make a real difference – after all, even with all the gains being made in weight reduction, fuel burn, alternative fuels, more direct routes, etc., we are still scheduled to hit 3% of global emissions by 2050.

We have also seen how slow the pace of change can be, and how difficult new technology can be to embed. Pratt & Whitney’s new PW1100G engine, for example, is described as delivering ‘game-changing reductions in fuel burn, environmental emissions, engine noise [and] operating costs’ [3], but its many problems currently make it inferior to the more mature and more reliable models, and are now delaying delivery of the new and more efficient aircraft models they power [4]. As for even more efficient power sources, like renewable energy, this is not expected to be an option in the near future, and ‘certainly not in the timeframes needed for urgent climate stabilisation’ [5].

Moving up to the lender level, initiatives like the recently launched Green Loan Principles might help to generate more momentum for green lending, and aviation asset finance would fall under a number of the nominated ‘Green Projects’ in that scheme [6]. This might encourage both borrowers and lenders to think about how their transactions can be structured to take advantage of the image-related benefits of actively investing in these Green Projects. However, the Green Loan Principles remain ‘voluntary recommended guidelines’, and are therefore unlikely to motivate the wholesale change required to seriously influence aviation’s environmental footprint.

Moving finally to the regulatory level, ICAO’s CORSIA (the Carbon Offsetting and Reduction Scheme for International Aviation) programme will come into force in 2021 (with a reporting obligation for all international flights kicking in on 1 January 2019), and will, like the passenger carbon offset initiative, require airlines to purchase carbon credits relating to environmental projects, in compensation for emissions made above 2020 levels. However, and also like the passenger carbon offset initiative, it will be voluntary until 2026 while the scheme is tested, and research has already identified enough ‘loopholes’ in the regime that it has been argued that CORSIA may not have much of an impact on aviation emissions at all [7].

So what else can we do?

There is no silver bullet here, and it is not realistic to campaign for substantially less global air travel given the current boom in demand and the infrastructure planned to facilitate that. We could start at the top by tightening and closing the loopholes in CORSIA to maximise its effect and make it a more meaningful instrument, and by making the Green Loan Principles mandatory for a certain percentage of lender books enforced with an anonymised annual public reporting requirement, perhaps in a format similar to that recently introduced for gender pay reporting in the UK.

We could also be more active in educating passengers about what carbon offsets are, what happens to their donation and what projects will benefit from it, so that people feel more comfortable purchasing them. We can use the technological advances that are in service to their best effect while even newer ideas come to fruition (such as, for example, increasingly using 2-engined aircraft for long haul flights and using larger 4-engined aircraft to ease local congestion, instead of the more traditional other way around, as we discussed several weeks ago here).

None of these things will work in isolation, but persistence and increasing awareness might help – even if only a little.




[4] See, for example:;

[5] Professor James Higham: