Not far from the hallowed spires and research labs of Oxford University, two workers in overalls and hard hats are searching for air travel’s “holy grail” – climate-friendly airline fuel made from nothing but carbon dioxide and green hydrogen.
That is how OXCCU chair Alan Aubrey describes the Oxford-based company’s mission to scale up its nascent production of so-called e-SAF, a synthetic hydrocarbon fuel that backers hope could one day become a viable, green alternative to traditional kerosene jet fuel.
“The beauty of this is that the inputs – CO2 and hydrogen – are at least theoretically unlimited,” the company’s CEO Andrew Symes told reporters during a visit to OXCCU’s experimental plant last year. “This industry – yes it starts small – but it can grow and scale and become very big.”
E-SAF can reduce planet-heating carbon emissions by up to 90% compared to conventional jet fuels. In contrast to more established forms of SAF, e-SAF does not require vast quantities of raw materials such as used cooking oil (UCO) or – more controversially – agricultural products such as sugar-based ethanol, soy or palm oil.
It is easy to see the fledgling industry’s appeal as airlines and governments fret over how to tackle air travel’s growing carbon emissions. They are closely watching the progress of startups such as OXCCU, whose backers include United Airlines, Saudi energy giant Aramco and Italy’s Eni.
Policymakers in the European Union and the UK are also taking note, and fuel providers are being mandated to supply growing amounts of e-SAF, starting with 0.2% in the UK in 2028 and 0.7% in the EU in 2030.
So far, e-SAF has only been used for a few high-profile test flights. In 2021, Dutch airline KLM used 5% SAF on a flight from Amsterdam to Madrid, and the British air force was the first to power a plane entirely on e-SAF when a two-seater made a short trip around a private airport.
But scaling up synthetic fuel production could be a long haul.
To fly or not to fly?
E-SAF remains prohibitively expensive to produce and so far its use has mainly been limited to demonstration projects, like OXCCU’s plant at Oxford Airport. Critics say it could be decades away from becoming commercially viable.
Producing green hydrogen from water to make the fuel requires huge amounts of renewable electricity, which the industry’s detractors say is a waste of scarce green power resources.
Such obstacles, they say, make it a distraction from the most obvious solution to aviation emissions: flying less.
Aviation’s Green Dream: Read our investigative series on Sustainable Aviation Fuel
“The idea that we can magic up this gigantic renewable capacity to produce e-fuel … it’s just not doable, it’s not going to be affordable, and it makes no sense from the perspective of using resources,” said Alethea Warrington, a campaigner on aviation issues at Possible, a UK-based NGO that promotes climate action.
Some climate campaigners are more positive about e-SAF. Aoife O’Leary, head of climate think-tank Opportunity Green, said there is a need to “deal with the unsustainable growth of aviation”, but that we should “also decarbonise the flights that exist”.
Acknowledging the huge renewable energy requirements needed to make green hydrogen, she said that “if paid for by the industry, then it would be additional to the renewable energy that exists otherwise”.
Aviation industry body IATA, the International Air Transport Association, urged governments in a recent statement to redirect into renewables “a portion of the $1 trillion in subsidies that governments globally grant for fossil fuel” and to develop policies“ to ensure SAF is allocated an appropriate portion of renewable energy production”.
The Possible group has called instead for measures to limit flight numbers, for example, a frequent flyer tax and efforts to promote rail transport.
But sweeping policies to reduce flying would be unpalatable for many governments and painful for passengers. Surveys from Europe and the US suggest that about a quarter of flights are taken to visit friends and relatives, and globally about 95% of flights are longer than 500 km (310 miles) – making other forms of transport less practical.
In the meantime, the world’s appetite for flying continues to grow, spurring efforts to find a way to tackle the carbon footprint of aviation – today the cause of about 2.5% of all energy-related emissions.
On its current trajectory, the aviation industry is on course to blow a big hole in the world’s goal to limit global warming to 1.5 degrees Celsius. According to the International Civil Aviation Organization, a UN agency, the sector’s emissions could double or even triple between 2015 and 2050.
That is partly because other sectors, such as road transport and power generation, are cutting their emissions by switching to renewable electric energy – still a distant technological prospect for commercial aircraft.
Fuel from air and water
Concern that plant-based SAF could increase competition for land and raise deforestation risks might boost efforts to ramp up e-SAF production.
New rules in the EU and the UK say only waste products such as UCO should be used to make SAF, but experts and industry insiders told an investigation by Climate Home News and its partner The Straits Times that in key UCO supplier Malaysia, unused or barely used palm oil is being passed off as waste oil.
In contrast, synthetic fuel is made by passing an electric current – produced with renewable electricity – through water, splitting it into hydrogen and oxygen gas. The oxygen is released harmlessly into the atmosphere, while the hydrogen is captured and mixed with carbon dioxide (CO2) to make the hydrocarbon jet fuel.
E-SAF producers such as OXCCU and US-based Twelve, which is set to supply Alaska Airlines and International Airlines Group, source their CO2 from industries that produce it as a waste product.
“It’s essentially getting two uses out of the carbon before it goes up into the atmosphere,” Symes said, adding that an even better option would be using technology to capture CO2 directly from the air, which would be fully circular and carbon neutral.
While OXCCU buys its green hydrogen, Twelve is planning to make its own at its factory in the US Pacific Northwest. “That’s something we’ve invested a lot of time and money into over the past few years,” the company’s vice president of business development Ashwin Jadhav told Climate Home.
Green hydrogen challenge
Scaling up green hydrogen production will be a “real challenge”, despite e-SAF’s “immense” potential, said Azim Norazmi, climate policy manager at IATA.
With the global aviation industry’s net-zero goal just 25 years away, he said plant-based biofuels – not e-SAF – will be the “biggest contributor” to meeting that target.
Aurelia Leeuw, Opportunity Green’s EU policy director, said one of the issues holding back e-SAF production is that airlines generally only want short-term contracts of around a year, while producers need longer-term certainty to justify investments in ramping up output.
The European Commission is expected to announce a sustainable aviation plan in the next few months. Leeuw and others are hoping this will help solve the problem by bringing international aviation into the EU’s Emissions Trading System (ETS) and using the funds raised from imposing charges on airlines to buy large quantities of e-SAF. An intermediary – such as the European Commission – would then sell the fuel on short-term contracts.
The idea under consideration would bring flights taking off in Europe that land outside the continent into the ETS, generating more funding from the aviation industry to support investment in e-SAF.
Leeuw said demand for e-SAF is also being held back by airlines and fuel suppliers assuming that the European Commission will water down its mandates and not fully apply penalties for fuel suppliers that do not meet them. The size of these penalties will depend on the price difference between conventional jet fuel, SAF and e-SAF – but are likely to be thousands of dollars per tonne, according to Brussels-based NGO Transport & Environment.
“The European Commission is saying the [e-SAF] targets are not up for debate. But the airlines and oil and gas incumbents are lobbying them hard and playing off the uncertainty that they themselves are creating,” she said.
“There must be no doubt that these… are the targets – and those are the penalties,” she added.
This article was developed with the support of Journalismfund Europe.
The post Air travel’s ‘holy grail’: Jet fuel made from CO2 and water prepares for take-off appeared first on Climate Home News.
Air travel’s ‘holy grail’: Jet fuel made from CO2 and water prepares for take-off
Climate Change
DeBriefed 15 August 2025: Raging wildfires; Xi’s priorities; Factchecking the Trump climate report
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Blazing heat hits Europe
FANNING THE FLAMES: Wildfires “fanned by a heatwave and strong winds” caused havoc across southern Europe, Reuters reported. It added: “Fire has affected nearly 440,000 hectares (1,700 square miles) in the eurozone so far in 2025, double the average for the same period of the year since 2006.” Extreme heat is “breaking temperature records across Europe”, the Guardian said, with several countries reporting readings of around 40C.
HUMAN TOLL: At least three people have died in the wildfires erupting across Spain, Turkey and Albania, France24 said, adding that the fires have “displaced thousands in Greece and Albania”. Le Monde reported that a child in Italy “died of heatstroke”, while thousands were evacuated from Spain and firefighters “battled three large wildfires” in Portugal.
UK WILDFIRE RISK: The UK saw temperatures as high as 33.4C this week as England “entered its fourth heatwave”, BBC News said. The high heat is causing “nationally significant” water shortfalls, it added, “hitting farms, damaging wildlife and increasing wildfires”. The Daily Mirror noted that these conditions “could last until mid-autumn”. Scientists warn the UK faces possible “firewaves” due to climate change, BBC News also reported.
Around the world
- GRID PRESSURES: Iraq suffered a “near nationwide blackout” as elevated power demand – due to extreme temperatures of around 50C – triggered a transmission line failure, Bloomberg reported.
- ‘DIRE’ DOWN UNDER: The Australian government is keeping a climate risk assessment that contains “dire” implications for the continent “under wraps”, the Australian Financial Review said.
- EXTREME RAINFALL: Mexico City is “seeing one of its heaviest rainy seasons in years”, the Washington Post said. Downpours in the Japanese island of Kyushu “caused flooding and mudslides”, according to Politico. In Kashmir, flash floods killed 56 and left “scores missing”, the Associated Press said.
- SOUTH-SOUTH COOPERATION: China and Brazil agreed to “ensure the success” of COP30 in a recent phone call, Chinese state news agency Xinhua reported.
- PLASTIC ‘DEADLOCK’: Talks on a plastic pollution treaty have failed again at a summit in Geneva, according to the Guardian, with countries “deadlocked” on whether it should include “curbs on production and toxic chemicals”.
15
The number of times by which the most ethnically-diverse areas in England are more likely to experience extreme heat than its “least diverse” areas, according to new analysis by Carbon Brief.
Latest climate research
- As many as 13 minerals critical for low-carbon energy may face shortages under 2C pathways | Nature Climate Change
- A “scoping review” examined the impact of climate change on poor sexual and reproductive health and rights in sub-Saharan Africa | PLOS One
- A UK university cut the carbon footprint of its weekly canteen menu by 31% “without students noticing” | Nature Food
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
Factchecking Trump’s climate report
A report commissioned by the US government to justify rolling back climate regulations contains “at least 100 false or misleading statements”, according to a Carbon Brief factcheck involving dozens of leading climate scientists. The report, compiled in two months by five hand-picked researchers, inaccurately claims that “CO2-induced warming might be less damaging economically than commonly believed” and misleadingly states that “excessively aggressive [emissions] mitigation policies could prove more detrimental than beneficial”80
Spotlight
Does Xi Jinping care about climate change?
This week, Carbon Brief unpacks new research on Chinese president Xi Jinping’s policy priorities.
On this day in 2005, Xi Jinping, a local official in eastern China, made an unplanned speech when touring a small village – a rare occurrence in China’s highly-choreographed political culture.
In it, he observed that “lucid waters and lush mountains are mountains of silver and gold” – that is, the environment cannot be sacrificed for the sake of growth.
(The full text of the speech is not available, although Xi discussed the concept in a brief newspaper column – see below – a few days later.)
In a time where most government officials were laser-focused on delivering economic growth, this message was highly unusual.
Forward-thinking on environment
As a local official in the early 2000s, Xi endorsed the concept of “green GDP”, which integrates the value of natural resources and the environment into GDP calculations.
He also penned a regular newspaper column, 22 of which discussed environmental protection – although “climate change” was never mentioned.
This focus carried over to China’s national agenda when Xi became president.
New research from the Asia Society Policy Institute tracked policies in which Xi is reported by state media to have “personally” taken action.
It found that environmental protection is one of six topics in which he is often said to have directly steered policymaking.
Such policies include guidelines to build a “Beautiful China”, the creation of an environmental protection inspection team and the “three-north shelterbelt” afforestation programme.
“It’s important to know what Xi’s priorities are because the top leader wields outsized influence in the Chinese political system,” Neil Thomas, Asia Society Policy Institute fellow and report co-author, told Carbon Brief.
Local policymakers are “more likely” to invest resources in addressing policies they know have Xi’s attention, to increase their chances for promotion, he added.
What about climate and energy?
However, the research noted, climate and energy policies have not been publicised as bearing Xi’s personal touch.
“I think Xi prioritises environmental protection more than climate change because reducing pollution is an issue of social stability,” Thomas said, noting that “smoggy skies and polluted rivers” were more visible and more likely to trigger civil society pushback than gradual temperature increases.
The paper also said topics might not be linked to Xi personally when they are “too technical” or “politically sensitive”.
For example, Xi’s landmark decision for China to achieve carbon neutrality by 2060 is widely reported as having only been made after climate modelling – facilitated by former climate envoy Xie Zhenhua – showed that this goal was achievable.
Prior to this, Xi had never spoken publicly about carbon neutrality.
Prof Alex Wang, a University of California, Los Angeles professor of law not involved in the research, noted that emphasising Xi’s personal attention may signal “top” political priorities, but not necessarily Xi’s “personal interests”.
By not emphasising climate, he said, Xi may be trying to avoid “pushing the system to overprioritise climate to the exclusion of the other priorities”.
There are other ways to know where climate ranks on the policy agenda, Thomas noted:
“Climate watchers should look at what Xi says, what Xi does and what policies Xi authorises in the name of the ‘central committee’. Is Xi talking more about climate? Is Xi establishing institutions and convening meetings that focus on climate? Is climate becoming a more prominent theme in top-level documents?”
Watch, read, listen
TRUMP EFFECT: The Columbia Energy Exchange podcast examined how pressure from US tariffs could affect India’s clean energy transition.
NAMIBIAN ‘DESTRUCTION’: The National Observer investigated the failure to address “human rights abuses and environmental destruction” claims against a Canadian oil company in Namibia.
‘RED AI’: The Network for the Digital Economy and the Environment studied the state of current research on “Red AI”, or the “negative environmental implications of AI”.
Coming up
- 17 August: Bolivian general elections
- 18-29 August: Preparatory talks on the entry into force of the “High Seas Treaty”, New York
- 18-22 August: Y20 Summit, Johannesburg
- 21 August: Advancing the “Africa clean air programme” through Africa-Asia collaboration, Yokohama
Pick of the jobs
- Lancaster Environment Centre, senior research associate: JUST Centre | Salary: £39,355-£45,413. Location: Lancaster, UK
- Environmental Justice Foundation, communications and media officer, Francophone Africa | Salary: XOF600,000-XOF800,000. Location: Dakar, Senegal
- Politico, energy & climate editor | Salary: Unknown. Location: Brussels, Belgium
- EnviroCatalysts, meteorologist | Salary: Unknown. Location: New Delhi, India
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
This is an online version of Carbon Brief’s weekly DeBriefed email newsletter. Subscribe for free here.
The post DeBriefed 15 August 2025: Raging wildfires; Xi’s priorities; Factchecking the Trump climate report appeared first on Carbon Brief.
DeBriefed 15 August 2025: Raging wildfires; Xi’s priorities; Factchecking the Trump climate report
Climate Change
New York Already Denied Permits to These Gas Pipelines. Under Trump, They Could Get Greenlit
The specter of a “gas-for-wind” compromise between the governor and the White House is drawing the ire of residents as a deadline looms.
Hundreds of New Yorkers rallied against new natural gas pipelines in their state as a deadline loomed for the public to comment on a revived proposal to expand the gas pipeline that supplies downstate New York.
New York Already Denied Permits to These Gas Pipelines. Under Trump, They Could Get Greenlit
A “critical assessment” report commissioned by the Trump administration to justify a rollback of US climate regulations contains at least 100 false or misleading statements, according to a Carbon Brief factcheck involving dozens of leading climate scientists.
The report – “A critical review of impacts of greenhouse gas emissions on the US climate” – was published by the US Department of Energy (DoE) on 23 July, just days before the government laid out plans to revoke a scientific finding used as the legal basis for emissions regulation.
The executive summary of the controversial report inaccurately claims that “CO2-induced warming might be less damaging economically than commonly believed”.
It also states misleadingly that “excessively aggressive [emissions] mitigation policies could prove more detrimental than beneficial”.
Compiled in just two months by five “independent” researchers hand-selected by the climate-sceptic US secretary of energy Chris Wright, the document has sparked fierce criticism from climate scientists, who have pointed to factual errors, misrepresentation of research, messy citations and the cherry-picking of data.
Experts have also noted the authors’ track record of promoting views at odds with the mainstream understanding of climate science.
Wright’s department claims the report – which is currently open to public comment as part of a 30-day review – underwent an “internal peer-review period amongst [the] DoE’s scientific research community”.
The report is designed to provide a scientific underpinning to one flank of the Trump administration’s plans to rescind a finding that serves as the legal prerequisite for federal emissions regulation. (The second flank is about legal authority to regulate emissions.)
The “endangerment finding” – enacted by the Obama administration in 2009 – states that six greenhouse gases are contributing to the net-negative impacts of climate change and, thus, put the public in danger.
In a press release on 29 July, the US Environmental Protection Agency said “updated studies and information” set out in the new report would “challenge the assumptions” of the 2009 finding.
Carbon Brief asked a wide range of climate scientists, including those cited in the “critical review” itself, to factcheck the report’s various claims and statements.
The post Factcheck: Trump’s climate report includes more than 100 false or misleading claims appeared first on Carbon Brief.
https://www.carbonbrief.org/factcheck-trumps-climate-report-includes-more-than-100-false-or-misleading-claims/
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