Energy & Green Tech

According to new research, sustainable aviation fuel is not a panacea for the industry’s massive climate problems.

The unprecedented COVID-19 flight ban has caused a rapid recovery in the global airline industry. Even more rapidly than before the pandemic, airlines are expanding in some parts of the world, like the Middle East.

In any case, how might the business keep on developing while at the same time doing its reasonable portion for environmental change? Except if worldwide avionics changes tack, its ozone-depleting substance emanations are projected to cause around 0.1 °C of an all-out Earth-wide temperature boost by 2050.

The aviation and energy industries are promoting so-called “sustainable aviation fuels” as the best option. These fuels can be made from waste like used cooking oil, synthetic kerosene, or organic matter like plants (also known as biomass).

Be that as it may, as our new exploration distributed in The Study of the All-Out Climate shows, economical flying fuel is certainly not a silver projectile. There is not enough land or renewable energy potential on Earth to produce all of the sustainable fuels that airlines require, even if the industry could make the change.

An extreme inquiry
In 2021, the Worldwide Air Transport Association delivered an arrangement for carriers to achieve net-zero carbon by 2050.

American Airlines, Qantas, and Air New Zealand, among others, have made similar commitments.

However, there are few low-carbon alternatives to conventional fossil fuel for jet aircraft. Because of this, reducing emissions from the aviation industry is extremely challenging.

Liquid hydrogen and batteries are two options that face significant obstacles. For instance, neither is appropriate for long-distance flights. Because of this, the aviation industry is turning to sustainable fuels.

Effectively, these fuels perform similarly to those derived from fossil fuels. They are reasonable for long flights and can be utilized in existing planes, so aircraft wouldn’t need to supplant entire armadas.

However, there is currently very little production of sustainable aviation fuel, and it is significantly more expensive than fossil jet fuel.

Practical avionics fuel additionally raises serious ecological worries. So is the change really attainable? Our new examination sets off to address this inquiry.

What we found

The 12 “roadmaps,” or plans, for decarbonizing the global aviation industry were the focus of our study. Academics, businesses, and outside groups all published them.

We discovered that, in the medium term, the plans heavily rely on biofuels and synthetic e-kerosene.

Currently, all commercially used sustainable aviation fuels are made from food waste like cooking oil or animal fat. Larger quantities of raw materials can be obtained from energy crops like soy and willow, agricultural residues like husks and bagasse, and forest biomass like logging waste and manufacturing waste, but chemical engineering processes for converting these materials into fuel are still in their infancy.

To “split” the water (a process known as electrolysis) and produce hydrogen, e-kerosene needs electricity generated by renewable energy sources in order to be produced in a clean manner. Carbon dioxide is then added to the hydrogen.

A number of fundamental issues with sustainable aviation fuels were largely left out of the roadmaps, according to our investigation.

The first is the enormous requirement for clean energy and biomass. On average across the guides, delivering feasible aeronautics energy would expect around 9% of worldwide sustainable power and 30% of accessible biomass in 2050. Even so, in 2050, about 30% of airline fuel would come from fossil fuels.

Biomass resources are also used by other industries. For instance, skincare products in the cosmetics industry contain tallow. Bagasse — the mash left after sugar stick juice is removed — is utilized for heat in sugar plants. As a result, the demand for sustainable aviation fuels runs the risk of displacing other businesses.

Second, the most common way of changing unrefined components into economical flying powers prompts a significant loss of energy and intensity. E-kerosene only uses about 15% of the primary renewable electricity that is still available to power the aircraft.

This is not only inefficient, but it also leaves less clean energy for industries that want to reduce their carbon footprint.

Thirdly, the production of sustainable aviation fuels results in emissions of greenhouse gases. For instance, the cultivation of bio-crops necessitates the use of harvesting equipment, transport, and emissions-intensive fertilizer.

In addition, extensive rainforest areas are already being cleared out to make way for biofuel-producing crops. Assuming that manageable aeronautics fuels were delivered along these lines, they’d be extensively worse for the environment than non-renewable energy sources.

At last, carbon dioxide isn’t the main outflow that contributes to environmental change. Soot, water vapor, and nitrogen oxides are additional examples. The question of whether sustainable aviation fuels will solve this issue is open to debate at this point.

“Unrealistic and irresponsible”

The aforementioned list does not include all of the potential effects that sustainable aviation fuels could have on the environment. However, it is evident that, despite the fact that the fuels will be useful in some way, the industry’s growth plans are ill-conceived and reckless.

Private and government ventures ought to be more coordinated to bring down carbon-intensive modes of transport, like rail. In addition, the traveling public must adopt a new mindset regarding how frequently and how far we must travel.

Flying isn’t the main business that must quickly decarbonize in the coming years. The entire worldwide energy framework needs to change.

This means that airlines can’t claim to be “sustainable” if they use more than their fair share of limited resources.

More information: Susanne Becken et al, Implications of preferential access to land and clean energy for Sustainable Aviation Fuels, Science of The Total Environment (2023). DOI: 10.1016/j.scitotenv.2023.163883

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