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
Cleaner cooking projects in the UN carbon market will have to set aside a share of their credits to insure against the risk that the trees they save are lost to fire, drought or logging, after the market’s regulator rejected calls to exempt the sector.
The requirement is part of a new rulebook that the Paris Agreement carbon market regulator – the Article 6.4 Supervisory Body – approved last Friday for programmes that aim to cut emissions by distributing new and cleaner cookstoves in regions that still burn wood or charcoal for cooking.
These are the UN mechanism’s first rulebooks for cookstoves, one of the carbon market’s most popular credit types and also one of its most criticised for overstating climate benefits.
They consist of two methodologies: one for programmes that aim to cut greenhouse gas emissions by distributing more efficient cookstoves that burn less wood or charcoal, and a separate methodology for projects shifting households to lower-emissions cookers running on electricity or liquid petroleum gas (LPG).
Mkhuthazi Steleki, the South African chair of the Supervisory Body, said “this decision gives cleaner cooking projects a new pathway under the UN carbon market, with clear rules to ensure that each credit represents a real and credible emission reduction”.
Industry and NGOs lobby to weaken UN carbon credit rules in “coordinated” push
In copycat submissions and a private briefing to government officials, the groups have opposed a proposal to tighten safeguards for emissions offsetsLaunch of Africa Energy Bank delayed again in blow to oil and gas hopes
Repeated delays are raising questions about the bank’s momentum and whether it can mobilise investment to finance Africa’s oil and gas ambitions in an era of energy transition
Exemption push rejected
More efficient cookstove projects earn credits based on the amount of carbon they save by preserving trees that would have otherwise been cut down and burned for fuel. But if those trees later burn in a wildfire or are logged, the carbon stored would be released anyway, erasing the climate benefits of the credits.
Several carbon credit developers, conservation NGOs and the UN Environment Programme (UNEP) disputed that cookstove projects face this risk, in what critics described as a “coordinated lobbying campaign”.
They argued that, unlike forest protection schemes, this type of credit represents a “flow” of avoided emissions rather than a “stock” of stored carbon that can be released. They also warned that requiring a buffer would impose disproportionate costs and undermine the financial viability of these activities.
But the UN carbon market regulator was not persuaded by the argument. It decided that projects would have to protect against this reversal risk by handing over a percentage of credits to a so-called “buffer pool” instead of selling them.
‘New paradigm’
The amount of credits to be given up is calculated by applying different methods for natural risks, like wildfires, droughts or hurricanes, and human-caused ones, such as logging or land clearing.
For natural risks, project developers will need to apply local risk values derived from new modelling published by a group of independent scientists.
Campaigners have broadly welcomed the decision. Federica Dossi, an expert at Brussels-based advocacy group Carbon Market Watch, said it sets a new paradigm for calculating reversal risk based on empirical data. “This approach is grounded in science and we hope to see this now being adopted by other carbon crediting mechanisms in the voluntary market,” she added.
Backers claim this method is more rigorous than current practice in the voluntary carbon market, which largely relies on expert guesswork.
Pre-COP draws attention to Pacific’s climate plight and 1.5C goal
Pushback over science
As Climate Home News previously revealed, the same industry and NGO groups that sought an exemption from the “buffer pool”, along with some corporate buyers, criticised the use of a study backed by the UN carbon market’s experts that recommended the new risk assessment approach.
The groups pushed for more flexible rules that would have allowed natural risk values drawn from other sources, including national databases, or from the project developers themselves.
While the Supervisory Body rejected this approach, it gave project developers and countries the option to propose alternative values that would first need to be vetted by the mechanism’s expert panel and then approved by the regulator.
A carbon market expert told Climate Home News that, while it is too early to say how this provision will be used, they expect requests will have to be backed up with solid scientific evidence, lowering the risk of unfounded claims.
Policy discounts questioned
To guard against human-caused risks, projects will need to apply a flat 20% value set by the Supervisory Body, at the bottom of the 20-45% range recommended by its technical experts ahead of last week’s meeting.
That value can be further reduced by up to two-thirds if the host country has an emission-reduction plan covering forests, a long-term climate strategy and a framework for the UN’s REDD+ forest protection scheme.
Injy Johnstone, senior research fellow at the Munich-based Max Planck Institute, said that, while these are important governance measures, their existence does not necessarily demonstrate that the underlying risk of forest carbon loss has been reduced.
“It is important to distinguish between evidence of actual risk reduction and assumptions about the effectiveness of policy commitments,” she added.
Moving target
A UN source told Climate Home News that, under the approved formula, improved cookstove projects must set aside at least 9% of credits linked to saved wood if they operate in the lowest-risk areas and the host country can claim all available discounts. The share of credits rises significantly in regions with high natural risk values, such as Guyana, Sri Lanka and Timor Leste, or that do not have REDD+ programmes.
These factors could change in the future as the Supervisory Body asked its technical experts to recommend revisiting the risk values “should credible new evidence arise”.
Climate change is likely to make forest destruction events, such as wildfires or hurricanes, more frequent and more severe in certain regions. Meanwhile, national policies on forest protection can shift significantly depending on government changes.
Johnstone said the UN carbon market needs periodic reassessment to respond to new evidence showing that previously assumed levels of risk were too low.
“The integrity of credits is not guaranteed simply because a reversal risk tool exists,” she added. “The real test will be whether the mechanism provides equivalent atmospheric protection over time, rather than simply introducing another layer of accounting requirements”.
The post UN carbon market forces cookstove projects to protect against forest loss appeared first on Climate Home News.
UN carbon market forces cookstove projects to protect against forest loss
Next week, diplomats from around the world will descend on Yerevan, Armenia, to negotiate a series of decisions under the UN Convention on Biological Diversity (CBD).
Between 19 and 30 October, 196 parties will gather to hammer out the precise wording of the dozens of legal texts that make up the decisions under the Conference of the Parties (COP) to the CBD.
This year’s summit is particularly significant, as it marks the halfway point between the agreement of the Kunming-Montreal Global Biodiversity Framework and the deadline for achieving its targets.
The CBD has found that countries are currently not on track to meet 22 out of the framework’s 23 targets.
During the fortnight, delegates will also be negotiating decisions relating to the two supplemental protocols to the CBD: the Cartagena Protocol, which covers biosafety; and the Nagoya Protocol, which covers access and benefit-sharing for the use of genetic resources.
(The Cartagena and Nagoya Protocols, which are each governed by a “meeting of the parties”, or “MOP”, have fewer parties than the CBD as a whole, with 173 and 141, respectively.)
Carbon Brief is tracking the progress of countries towards consensus on dozens of negotiating texts using the interactive table below.
The tracker includes texts from the COP, as well as the MOPs for the Cartagena and Nagoya protocols. It also includes draft decisions from the most recent subsidiary body meetings, as these form the starting point for the negotiations in Yerevan.
The CBD has three subsidiary bodies: the subsidiary body on scientific, technical and technological advice (SBSTTA), the subsidiary body on implementation (SBI) and the subsidiary body on article 8(j) and other provisions (SB8J).
SB8J focuses on issues related to the Indigenous peoples and local communities. It was established at COP16 in Cali, Colombia, in 2024.
The first two columns of the interactive tracker list the topic of each agenda item and the relevant body, with subsequent columns including dates, page counts and links to the original documents.
The table is searchable and can be sorted using the arrows in the header.
Areas of disagreement in UN draft texts are denoted by square brackets. Counting the brackets in a particular iteration of a text therefore gives a sense of how far parties are from reaching consensus.
The bracket column is colour-coded, with dark green indicating a low number of brackets and red indicating a high number of brackets remaining.
Texts can also present parties with choices using “options” or alternatives (“alt”), which are counted together in the sixth column of the table.
The key discussions in Yerevan will centre around two agenda items in particular. The first is the global review, which will assess progress towards the GBF and make recommendations for accelerating action.
The second is finance, which can be separated into two parts: resource mobilisation and the financial mechanism. On resource mobilisation, biodiverse global south countries are likely to push for an increased amount of international finance for conservation.
Disagreement over the creation of the financial mechanism led to the suspension of COP16 in Cali in October 2024, as parties failed to find agreement on the mobilisation of finance before the end of the summit.
Global south countries want the establishment of a separate financial mechanism under the control of the CBD; global north countries largely prefer to maintain the existing mechanism, which sits under the Global Environment Facility.
At the resumed session of COP16 in Rome in early 2025, countries agreed on a roadmap that would lead to the establishment of a permanent mechanism.
related
Analysis: Lula presidency saved at least 20,000km2 of Brazilian Amazon since 2022
Why land-use emissions have fallen by a third this century – in six charts
Analysis: 84% of nations miss deadline to identify ‘nature-harming’ subsidies by 2025
UK withdraws millions in funding from world’s second-largest rainforest in Congo
The post Interactive: Tracking negotiating texts at the COP17 biodiversity summit appeared first on Carbon Brief.
Interactive: Tracking negotiating texts at the COP17 biodiversity summit