From Climate Scepticism

By MARK HODGSON

The problem

A little over three years ago, the BBC’s Future Planet series informed us that “[a]round 2.4% of global CO2 emissions come from aviation. Together with other gases and the water vapour trails produced by aircraft, the industry is responsible for around 5% of global warming.” Worse still:

…emissions from planes are rising rapidly – they increased by 32% between 2013 and 2018. While improving fuel efficiency is gradually reducing the emissions per passenger, it is not keeping up with the rapid increase in total passenger numbers, which are projected to double in the next 20 years.

Seven years ago, CarbonBrief decided to do some sums and concluded that even if the aviation industry met its own targets, it would be consuming 12% of the global carbon budget compatible with the mythical 1.5C, by 2050. If it fails to meet its targets, things will be so bad that its share of that budget could rise to 27%.

What is to be done?

Well, the Guardian has just published an article on its website discussing the options. We are reminded of the problem:

…passenger numbers are booming, with rampant demand for travel after Covid. Airlines are gearing up for worldwide growth, as China reopens and Indian carriers expand.

Unfortunately the Holy Grail seems to be beyond us for now:

Bar the obvious solution of flying less, immediate tangible steps to cut CO2 are limited. Commercial flights using hydrogen or electric power are, at best, a hope for the future. Replacing old fleets with modern fuel-efficient planes for less CO2 a head is a step most airlines are taking – but that benefits the bottom line more than the environment when more people fly.

The magical elixir, it seems, is now “sustainable aviation fuel” (SAF). Unfortunately:

Airlines might be using “every single drop” of SAF available, but that amounts to 0.1% of the total jet fuel needed – and supplies are impossible to find in much of the world.

Synthetic or e-fuels are supposedly an answer – “seen as the most credible way forward by many – involving a process that draws carbon dioxide from the air, albeit energy-intensively, rather than using sources that are limited or problematic.”

Problematic solutions

Almost incredibly, one of the “problematic” solutions that has been touted is the use of animal fats. Pigs seem to be in the firing line Quite apart from the ethical problem of raising pigs in order to kill them so that flying can carry on with a clean conscience, there is a rather practical consideration too:

According to a report by the Brussels-based charity Transport and Environment, creating enough SAF for a transatlantic flight would require the fat of 8,800 pigs….

…Tim Clark, the president of Emirates Airlines, asked: “There’s only so many animals you can slaughter to get the oil … Where’s the feedstock?” For him, e-fuels are more feasible, but he warned: “Money is probably the biggest single blocker, because these are hugely expensive programmes. So I’m afraid that means nuclear coming into the mix. That’s not going to sit well with Greens, but in the end, I don’t see how you’re going to drive enough power to get your synthetic fuels and power the rest of the global economy sustainably with wind or whatever it may be.”

Oh dear, it’s a tricky conundrum. For once, however, the BBC beat the Guardian to the story. “Using pig fat as green jet fuel will hurt planet, experts warn”, they advised us as long ago as 31^st May. And the BBC gives us plenty of detail that is rather concerning:

The fact that animal fats are used as fuel will come as a surprise to many.

For centuries tallow and lard have been used to make candles, soaps and cosmetics.

However, over the last 20 years or so, biodiesel made from these animal wastes or from used cooking oils, has steadily grown in use in the UK and further afield.

Across Europe, fuel made from dead animals has grown fortyfold since 2006, according to the new research.

Much of this material is used in cars and trucks as biodiesel, which is classed as a sustainable fuel, and as such it has a much lower carbon footprint under the rules.

But UK and EU governments are now very keen to increase the use of these types of waste to make aviation greener.

To that end they are putting in place challenging mandates that will require airlines to use a bigger proportion of sustainable aviation fuel (SAF) in their tanks.

For the UK it’s going to be 10% by 2030, for the EU 6%.

Given what follows, the Guardian and the BBC must both be offering up thanks for Brexit:

With the UK likely to restrict the use of animal products and used cooking oils, flights that refuel across Britain will be likely to have only small amounts of animal-derived material in their engines.

In the EU, airlines will have a 6% sustainable aviation fuel target for 2030 of which 1.2% must come from e-kerosene. Assuming the remaining 4.8% is derived entirely by animal fat, that would require around 400 pigs per transatlantic flight.

Yet another dilemma

And that’s not all.

Among those industries who might have to source different ingredients if aviation consumes a greater share of animal fat are pet food manufacturers.

They currently utilise a significant amount of the better quality animal by-products to help feed the UK’s 38 million pets.

“These are really valuable ingredients for us and they are hard to replace, and they’re put to good use already in a very sustainable way,” said Nicole Paley, deputy chief executive of UK Pet Food, the manufacturers’ trade association.

“So actually diverting these ingredients to biofuels is actually creating another problem. It would put us in competition with the aviation industry. And when it comes to the purse strings of the aviation sector, the pet food industry would find it really difficult to compete.”…

…Many in the biofuel industry are concerned that the proposed changes might also see animal fats diverted from one form of transport to another.

“If you make a big incentive for use of these lipids, animal fats, and used cooking oils, in aviation, it will inevitably take it away from other things,” said Dickon Posnett from Argent Energy, a waste-based biodiesel producer in the UK and Europe.

“So if you want to increase aviation sustainability, at the expense of truck sustainability, then crack on. But that’s a decision for the government to make.”

Conclusion

Every “net zero” solution seems to cause problems. The Law of Unintended Consequences applies to net zero as ruthlessly as it does to everything else in life.