Why aviation's lofty net-zero ambitions are struggling to take flight

Aviation contributes about 2.5 per cent of global emissions. Getty Images

Emirates, Etihad, Qatar Airways and other airlines are at the heart of the Gulf’s economic diversification plans. With few usable land links, the region’s emergence as a tourism and business hub flies on the wings of a jet. But they could hit turbulence: the push to cut the heavy carbon dioxide emissions from flying.

Air travel is perhaps unfairly demonised among activities that emit greenhouse gases. It contributes about 2.5 per cent of global emissions, less than the 8 per cent coming from cement or the 7 per cent from steel making.

But there are good reasons to worry about aviation’s carbon footprint. It generates additional global warming through contrails – the linear high-altitude clouds formed around jet exhausts under certain atmospheric conditions. Its pollution continues to grow fast, unlike some other sectors, possibly almost tripling by 2050. Private jets have come under harsh criticism in Europe because of their high per person emissions and perceived frivolous use by the rich, with calls for a ban.

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And, unlike renewable or nuclear electricity generation, or electric road vehicles, low-carbon alternatives to petroleum-powered jets are not viable yet.

The issue will become more acute in the next few years. The huge and growing middle classes of South-East Asia, India and Africa are reaching levels of income where taking flights for pleasure and business becomes normal.

Supersonic flight may be returning to our skies, three decades or so after Concorde stopped operations. New technologies with less sonic boom and better fuel consumption could make it viable again. London to Dubai flights in three hours or so would be attractive to the wealthy and to top businesspeople.

But a modern supersonic flight would still burn two to three times as much fuel per person as a business class seat on a current wide-body jet.

Efficiency has crept up over the years, with today’s flights using half the fuel needed in 1990. These incremental gains can continue for a while. Tree-planting and other “offsets” that absorb carbon dioxide are offered by some airlines today, but there are worries about how reliable and permanent they are.

Yet, to meet international climate goals, all new aircraft delivered from the mid-2030s would need to be zero-carbon. That is only a decade away. How could this be achieved?

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Electric aircraft on the drawing board today could manage short haul flights up to 500 kilometres, enough to connect Dubai to all the Gulf capitals other than Kuwait City. Such short routes, though, represent only a small per cent of overall emissions.

Longer distances would require dramatic advances in battery chemistries. More realistically, although there might be some savings from hybrid electric models, medium- and long-haul flights will continue to rely on chemical fuels well beyond 2050.

That means some combination of three things: sustainable aviation fuel (SAF) made from biological materials, synthetic fuels that are practically equivalent to today’s jet fuel, or hydrogen.

SAF is already used today. Emirates has demonstrated A380 flights running entirely on SAF, and the UAE in 2023 announced a target to blend one per cent SAF into jet fuel by 2031. The EU has more aggressive requirements, requiring two per cent from this year, rising to 70 per cent by 2050.

But traditional pathways for making SAF either rely on waste feedstocks that will be in short supply, or on crops such as palm oil that contribute to deforestation.

A variety of chemical processes can turn hydrogen into near-perfect substitutes for kerosene. They are even superior: cleaner and less prone to form contrails. The hydrogen can be derived from water using renewable electricity, and combined with carbon dioxide captured from the atmosphere.

Hydrogen could also be used directly as fuel. It emits only water vapour when burnt. Hydrogen contains a tremendous amount of energy for its weight, three times as much as jet kerosene, but it has low density, requiring large tanks. Entirely new aeroplanes and engines would need to be designed, tested and delivered, and a new hydrogen fuelling infrastructure set up. That does not seem likely to happen on the required scale before the 2040s.

But, whether SAF, synthetics or hydrogen, airlines and fuel suppliers are passing the buck to each other. Airlines complain there is not enough sustainable fuel on the market and that it is too expensive; fuel companies say they need long-term commitments to be able to invest in production.

One obvious solution would be to require private planes to move very quickly to zero-carbon flight. Their wealthy users can presumably afford it, and it would kick-start the market for SAF, synthetic fuels or more ambitious designs.

But for mass aviation, more scalable and affordable solutions are needed. This poses one risk and two big opportunities for the Gulf.

The risk lies between moving too quickly or too slowly. Too fast, and Gulf airports would lose custom either to competitors in the bloc or regional rivals such as Turkey. Too slowly, and they may weaken global climate efforts, and provoke a backlash from climate-conscious partner nations. They might, for instance, lose access to European routes, or face boycotts by tourists.

The first opportunity, by contrast, is to produce synthetic fuels. Demand for green hydrogen has grown much slower than Gulf states had hoped. But green synthetic jet fuel has a guaranteed market, because of the EU rules, and a high price point that could get the nascent industry going. The Gulf’s high-quality wind and solar resources, its open land, geographic centrality, and long experience in oil refining and petrochemicals, all make it a leading contender as a synthetic fuel provider.

The other opportunity is more controversial. Why go to the trouble of pulling carbon dioxide from the air just to make fuel? Planes could continue running on conventional petroleum-based jet kerosene, while offsetting its emissions entirely with the direct air capture (DAC) of carbon dioxide. The offending carbon would then be permanently disposed of deep underground or turned into solid minerals.

Current DAC might cost about $500 per tonne of carbon dioxide, with a possible long-term target of $200. A Dubai-London economy class return flight, with ticket price currently about $800, would emit about 2 tonnes of carbon dioxide. Assuming that half of this could be saved with greater efficiency and SAF, the inclusion of DAC at future costs would bump up the ticket price by about a quarter.

That is expensive, but not insane. The Gulf’s exceptional energy and geological resources could make it a hub not just for luxury holidays, but for DAC too. That is an ideal way for both the oil and airline industries of the Gulf to keep flying high.