Flightpath to the future: Part 3 – Picking up the pace on European airline emissions

This is part 3 in my series on climate policy priorities for aviation in the next EU cycle. Part 1 looked at voters’ expectations and part 2 looked at the current policy pipeline. In part 3, let’s go blue sky and ask what it takes to shift up a gear (or several) to get aviation truly on track for net zero.

I’m starting this post on the train back from the Sustainable Skies summit at Farnborough Airport. The aviation industry puts on events like this to rehearse a policy narrative that supports the sector’s business objectives. This narrative has three pillars:

1. The industry has a climate plan, focused on ‘sustainable’ aviation fuel (SAF)
2. The industry is doing all it can to be on track to deliver this plan
3. Governments need to help pay for this plan

At the start of the event, the organisers polled the audience. Tellingly, even people working to deliver this plan don’t think it’s really working – and it’s not even close.

No doubt industry bosses would say this poll simply shows that governments aren’t doing enough to help. But I think there is a little voice in their heads telling them that something about this plan doesn’t quite add up. And I think they’re right.

The main problem with the SAF-first strategy is that all the things you need to make SAF (crops, wastes, or renewable energy) have better environmental uses.

Do we want to promote destructive monoculture crops over nature restoration?

With crops, the question is: what’s the best environmental use of land? One obvious answer is growing crops to feed people. Another important answer is restoring nature. David Attenborough is crystal clear that it’s not enough to simply slow the decline of nature – we need to restore nature and get wild spaces growing again.

This is vital for carbon as well as biodiversity. Agricultural expansion is the main driver of habitat destruction and species loss, so this is also where we should be targeting nature restoration, starting with nature-friendly farming practices and more plant-based diets (which use less land). The last thing we should be doing is opening up new markets for ecologically destructive monoculture crops. Fortunately, crop-based SAF is (mostly) off the menu in Europe.

Do we want to burn waste instead of preventing it?

With wastes, the well-known waste hierarchy sets out the best environmental uses. We should be reducing the amount of waste first and foremost, then recycling what’s left (keeping that carbon locked up in new products), and only burning it for energy (and releasing that carbon) as a last resort. Even then, if we’re burning the waste, we should be capturing the CO2 at the same time. This can be done in a power plant on the ground, but it can’t be done on an aeroplane in the sky.

It’s a similar story with industrial waste gases. We need to help steel companies adopt new clean technologies like hydrogen, rather than capturing their gases, only to release them back into the atmosphere again (at altitude, with extra warming effects).

Do we want to eliminate one tonne of airplane emissions or 10 tonnes of coal emissions?

With renewable electricity, the graph below shows you get better bang-for-buck, in carbon terms, by using it for any of the activities in the first six columns, compared with turning it into jet fuel (almost 10x as much if you’re displacing coal on the grid). This is because making SAF from renewables (aka e-fuels) needs a huge amount of energy, so the carbon saved per unit of energy is much lower.

On the other hand, wind turbines, solar panels and electrolysers (which make hydrogen out of electricity and water) all have three major benefits over crops and wastes, which mean that e-fuels clearly have the best long-term prospects of all the SAFs:

Wind, solar and electrolysers...

• need to grow to meet wider environmental goals,
• will get cheaper as they grow,
• are relatively energy efficient per acre of land.

Whereas farmland and wastes...

• need to shrink to meet wider environmental goals,
• will get more expensive as they shrink,
• are very energy inefficient per acre of land.

Carbon opportunity cost

It’s not true that “SAF?produces up to 70% less carbon emissions,” unless you explicitly say “on a lifecycle analysis (LCA) basis”. In fact, whether you’re making SAF from crops, wastes or renewables, when you burn these fuels, they produce the same CO2 (and similar levels of other pollutants) as fossil jet fuel.

Any environmental benefit comes upstream in the fuel production process, like when crops suck CO2 from the air through photosynthesis, when wastes are prevented from decomposing, and when renewable energy is generated. Tot up all these impacts (along with smaller ones like emissions from fuel transportation) and you get an ‘attributional’ LCA figure like 70%. This is how fuel suppliers and airlines view the fuels they make and use. Sounds great on paper.

But we’re not doing decarbonising on paper; we’re doing it in the real world. And in the real world, there’s an opportunity cost to using those resources for SAF, because they all have much better environmental uses, as described above. At the moment, this ‘carbon opportunity cost’ is not routinely factored into LCA, and so it wildly overstates the benefits of these fuels.

Factoring in this carbon opportunity cost would wipe out the emissions benefits of SAF for ***at least a couple of decades*** until all the targets for those better environmental uses have been achieved. This means that by the time SAF actually delivers real environmental benefit, we might be ready to start using more efficient zero emission aircraft instead (at least in some market segments). Thinking this way is called ‘consequential’ LCA, dealing with real-world consequences, and this is what policymakers need to focus on.

Beyond SAF?

To be clear: I’m not saying we don’t need SAF. I’m saying:

• We don’t need all SAF – just scalable, sustainable, additional e-fuels
• SAF is the last resort – we need to max out all the other levers first

There are a few ways to reduce reliance on SAF. Some are already supported by airlines because they reduce fuel burn (which saves money) without major new investment, such as airspace reform and incremental aircraft efficiency standards. These gains are rapidly capping out, but there are three big opportunities worth exploring.

First, we can radically rethink how we design planes. We could achieve emissions savings of up to 35% by designing planes to fly a little slower (8-9%) and lower (25,000-31,000 feet). These are major gains for minimal costs. Would you even notice if your flight took 11 hours rather than 10? Hat-tip to Finlay Asher for bringing this one to my attention.

Second, we can electrify short-haul routes. Just like electric cars, electric planes are far more efficient than fossil fuel engines (and even competitive with trains, according to Jayant Mukhopadhaya ). The physical limits of batteries mean they can only do shorter distances though, barring a quantum leap in battery technology (which is not inconceivable, given the pace of progress on battery development).

Third, we can get serious about hydrogen aircraft. Hydrogen has a lot of issues, but it is better, in resource efficiency terms, than all the alternatives except batteries. And unlike batteries, it isn’t as limited on range.

In fact, because hydrogen is so light, it gets more economical the further you fly (hat-tip to Aviation Impact Accelerator (AIA) ). Hydrogen planes will start out small, serving shorter routes, because it will take time to derisk the technology and develop the surrounding infrastructure. But over time, it will deliver better and better performance over longer and longer distances.

Sorting the signal from the noise

By the end of the century, we could be running European aviation entirely on electricity for short-haul, green hydrogen for longer flights, and truly sustainable e-fuels for the rest. No fossil fuels, no biofuels. That’s the future we need to aim for, clearly set out by groups like the Sasha Coalition, but we need to start now. We can’t afford to delay any further.

Because aircraft manufacturers are making decisions on their next big product launches now. The EU’s dreadful decision to label new ***fossil-fuelled*** planes as 'sustainable' in its green taxonomy (yes you did read that right, and yes it is being challenged in the courts) is prompting Airbus to scale back its plans for hydrogen planes and shift focus onto new fossil-fuelled A320 upgrades. This trend needs reversing, fast.

Moonshot

Here’s the exciting thing: Europe is actually really good at making planes. Airbus is the world’s #1 airframer. America’s Boeing is beleaguered by safety issues and China’s Comac is still a minnow in the market. But there’s no room for complacency.

Xi Jinping has dubbed Comac’s C919 narrowbody plane (targeting the same segment as the A320 series, which drives Airbus’ profits) as the “dream of a nation”. We’ve already seen in batteries, renewables and semiconductors just how fast China can move with sufficient political motivation.

It’s time for Europe to flex its aerospace muscle and launch a moonshot programme on zero emission aircraft. If we don’t, then we shouldn’t be surprised if we fail on climate, lose our aerospace leadership spot, or both. If we do seize this opportunity, then we will see economic multipliers ripple through the region as this investment in innovation helps revive our sluggish productivity and ailing economic growth.

The EU is gradually moving in this direction, with incentives for zero emission aircraft baked into the impact assessment for its new 2040 climate target, alongside various industry collaborations. This is a good start, but we must go further.

Blue sky thinking

This post is already too long, and I’m just now getting to actual policies. The truth is, we need to get the best policy brains around a table to come up with fresh ideas. Here are a few conversation-starters to get things going:

• Use the revenues from the strengthened ETS to supercharge R&D into zero emission aircraft
• Require all new runways to be zero-emission, fuelling planes with green electricity or hydrogen (I've written about this before)
• Introduce fleet mandates for zero emission aircraft in the short and medium-haul segments
• Scrap the ludicrous decision to label new fossil-fuelled aircraft as ‘green’

Well done for making it this far. If you can communicate all this more crisply than I’ve managed, get in touch! Just one more post to go, where we pull all this together into a coherent narrative and policy programme. See you then…