Decarbonising Aviation. Plane easy?

Tackling aviation emissions is challenging; what are the options the Government should be looking at?

By George Smeeton

Information on this page correct as of:

Unfortunately, no. As most people are aware, decarbonising some sectors of life is relatively easy. Solar panels are now mainstream, and electric vehicles will be in the very near future. But some sectors are really, really hard. Aviation is one of those sectors. But just how hard, exactly?

Tackling greenhouse gas emissions presents a challenge to airline operators. Image: Rosedale7175, creative commons licence
Tackling greenhouse gas emissions presents a challenge to airline operators. Image: Rosedale7175, creative commons licence

Official advice

A bit of background. The UK committed itself to become a net zero nation by 2050 in June of this year, off the back of a (requested) Committee on Climate Change (CCC) report. The recommendations of that report said that committing to net zero should a) involve the aviation sector, and that b) there should be no use of international credits.

It also suggested that the aviation industry could pay the annual costs of removing its emissions (yep, it did: p.29), but crucially it did not suggest how it should pay. Could, for instance, the International Airlines Group (the parent company of British Airways, the UK’s largest airline) become a major landowner and a conservation champion by rewilding vast swathes of the country, thereby turning them into carbon sinks? Or should IAG simply have to pay a carbon tax for every tonne of carbon it emits? (Which in turn would be hypothecated to growing trees?) The CCC expects UK aviation to still be emitting at least 31 MtCO2 in 2050, which means - whilst there is plenty of scope for electric planes and planes fuelled by biofuels or synthetics - it still expects some planes to burn oil taken from under the ground then.

Following June’s activity, the CCC sent a letter to the Transport Secretary where it stresses that the first thing the Government should be doing is international, for the obvious reason that planes fly between counties, but further goes on to say that “carbon pricing, support for research, innovation and deployment and measures to manage growth in demand” should all be utilised. In essence, we should expect a raft of domestic aviation policies over the next couple of years (it should be noted that one recent survey found that most people in the UK back limits on flying to tackle climate change. The demand for reducing demand is already there).

Offsets

So how should the likes of IAG react? After all, 2050 is ages away, right? Well, yes and no. The average age of BAs fleet of planes is 13.5 years, but the oldest plane it has (named the City of Portsmouth) is actually 29 years old. So if this age spread still stands for BA in 2050, then there is a chance that the next plane it buys will still be in service when the UK becomes net zero. If this plane is not electric (it won’t be), then BA will have to either source zero-carbon fuel for it (technically possible, but really expensive right now), or offset its emissions in the UK. Which means, all things being equal, this plane will incur extra fuel-based costs in 2050, and possibly earlier.

Unbeknown to most, the UK Government has just formally completed a consultation on what the aviation industry should look like in 2050 (a consultation paper it has imaginatively called “Aviation 2050”), which will culminate in a white paper (ie a paper setting out final policies) sometime in 2020. There is a full section in the document on (chapter 3.77 onwards), which is full of the fluffiest, woolliest language you will ever find in a Government document, but does also propose that aviation emissions in 2050 should be the same as they were in 2005, which was 37.5 MtCO2e.

This is interesting, as in 2017 the UK's total forest stock sucked 18 MtCO2e out of the air. This means that the UK's forests would have to more than double in land area (from 13% of the country today) to offset the UK's future aviation emissions. Is this feasible? And if aviation uses all future afforestation, then no other sector can use it. What about industry? Or beef production? Besides, the CCC suggested that forest cover should rise to 17% of the UK by 2050 - not 26%.

Alternative fuels

This means, effectively, that the aviation industry has to find another solution. It could invest in capturing carbon directly from the air, or something else (BECCS?), but is likely in the UK to have to use some combination of synthetic fuel or biofuel. This is problematic though, as currently there are virtually no commercial vendors of synthetic jet fuel or jet biofuels.

Technologies such as algal biofuels are not currently being produced at scale. Image: AgriLife Today, creative commons licence
Technologies such as algal biofuels are not currently being produced at scale. Image: AgriLife Today, creative commons licence

Synthetic fuels are made in a lab or factory, rather than refined from oil pulled from the ground. However, they are a) not made on a large enough scale yet, and b) use a lot of energy to be made. Crucially, this energy use means that synthetic fuel production is not zero or low carbon (yet?). This would suggest that biofuels should be the answer, but biofuels come with their own problems.

The biggest by far is the simple fact that land used for biocrops for planes is not used for crops for human or animal consumption. These demands on the UK's land mean that, unless there is a major cultural change (like a marked reduction in the amount of meat consumed), UK-grown biofuels are not likely to be a major part of the UK aviation industry’s 2050 fuel demands. This further means that either a) aviation, and by extension the UK, will miss its net zero targets, or b) some serious R&D needs to go into zero (or near zero) carbon planes.

Clearly aiming for option a is a non-starter, so option b wins out. Whilst there is 30 years to the UK's net zero deadline, due to aviation’s long lead times this means that some measures need to be taken soon, and the brutal truth is that it is not obvious what those measures need to be. One recent eminent report suggested that biofuels should be reserved for the aviation sector, due to the dearth of other solutions. Furthermore, it suggested that the aviation sector is “a high priority for innovation support”.

So, over to you, Mr Shapps. Just what policy levers will be pulled?

(Finally, there is a small footnote to this debate. As this infographic shows, there are 19 other nations that are currently either considering or have implemented a net zero target. Importantly, in addition to these, the EU is also considering a 2050 target. This matters to UK aviation, as 67% of the flights taking off from the UK are headed to somewhere in the EU. This means that even if the UK Government did nothing at all, the UK's aviation industry would still have to do something.)