The UK would have to dedicate half of its farmland or more than double its total supply of renewable electricity to produce enough jet fuel to meet its ambitions of “zero jet”, or net zero flight, scientists said.
A report published on Tuesday by the Royal Society argues that there is no single, clear and sustainable alternative to jet fuel that can sustain the current level of flight.
Scientists say that while the government and aviation industry have set a 2050 goal to balance emissions, huge challenges remain around the availability, costs and impacts of alternative fuels, as well as the need for new types of planes and infrastructure. airport around the world. world to allow for the most likely long-term solutions.
More research and significant investment would be needed, the scientists say, to address questions in four types of fuel – green hydrogen (made from water using renewable energy), biofuels (energy crops and waste), ammonia and synthetic fuels or e-fuels.
Producing enough biofuels would require around half of the UK’s farmland, while other feedstocks such as municipal waste could only contribute “a very small fraction” of jet fuel requirements, they report.
Producing enough hydrogen or green ammonia to power future planes would require well over double all of the UK’s current renewable electricity generation capacity. E-fuels or synthetic fuels – which are produced by capturing and converting carbon dioxide from the air – would require five to eight times the UK’s current capacity.
The Royal Society said the findings highlight the challenges of decarbonizing aviation, and there is still much work to be done on how these fuels are stored and handled – as well as their actual environmental impacts in production and when used in flight.
aviation COtwo represented 2.4% of global emissions in 2019. UK aviation (both international and domestic) caused 8% of the country’s greenhouse gas emissions.
Graham Hutchings, regius professor of chemistry at Cardiff University and chairman of the report’s working group, said: “We need to be very clear about the strengths, limitations and challenges that must be addressed and overcome if we are to scale up the new technologies needed in a few decades.” .
The report said more research is needed to understand how alternative fuels would affect contrails, which contribute significantly to the aviation warming effect.
Sustainability would depend on how fuel alternatives are produced, said Professor Marcelle McManus, director of the Sustainability Institute at the University of Bath. “We need consistency and we need to apply this globally, because the adoption of any of these new technologies will create demands and pressures for land, renewable energy or other products that could have environmental or economic effects.”
As airlines look to sustainable fuels to reduce COtwo emissions at 70-80%, McManus said that for many different types of fuels labeled as sustainable, “definitely not the case” that a change would result.
The Doctor. Guy Gratton, associate professor of aviation and the environment at Cranfield University, said: “The term SAF (sustainable aviation fuel) is quite nebulous… not everyone has the same environmental footprint.”
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The government has said it will force airlines to use SAFs for at least 10% of their fuel needs by 2030. Gratton said that while that target could be met, what the overall environmental benefits would be “a more complex issue”.
He said creating new fleets of radically different planes to operate with hydrogen-powered planes would be extremely expensive but feasible, adding: “It seems reasonable to say that if we get the investment in research and infrastructure we could get close to a massive reduction in emissions. . towards the 2050 target”.
A spokesman for industry body Airlines UK said the industry is committed to reaching net zero by 2050. They said: “There is no silver bullet but modernizing airspace to make flying more efficient by introducing new emission technologies zero such as hydrogen aircraft and increasing the use of sustainable aviation fuels in this decade, this can be achieved.”
The spokesperson said the industry is working closely with the government to “maximize the enormous economic and environmental opportunities of leading the zero-jet transition.”
A Virgin Atlantic Boeing 787 will fly from London to New York later this year powered entirely by fuel made primarily from waste oils and fats, in what is being billed as the first net-zero transatlantic flight.