UK government targets for “sustainable aviation fuels” (SAFs) will only cut emissions from the sector to 0.8% below current levels in 2040, Carbon Brief analysis shows.
From 2025, flights taking off from the UK must use a fixed share of SAFs, which are largely made from waste products. This share will gradually rise from 2% next year to 22% in 2040.
The government says its “SAF mandate” will cut aviation emissions by 6.3m tonnes of carbon dioxide equivalent (MtCO2e) in 2040.
However, Carbon Brief analysis of government forecasts shows this being almost entirely wiped out by rising demand for air travel, meaning emissions would only fall by 0.8% overall.
The SAF mandate is the most substantial policy to date under the UK government’s “jet-zero” strategy for decarbonising air travel, which eschewed efforts to limit demand. The mandate relies heavily on fuels made from used cooking oil and other waste products, which are in limited supply.
No change
The SAF mandate will require jet fuel suppliers to ensure that an increasing share of the product they supply is “sustainable”. This is meant to encourage investment in new facilities to produce SAFs.
Fuels described as SAFs include those made from waste, such as used cooking oil, household waste and offcuts from the forestry sector.
Despite their name, SAFs produce just as many emissions as fossil fuels when burned to power planes.
However, they generally – although not always – have a lower overall “lifecycle” carbon footprint than petroleum-based jet fuel. This is due to CO2 emissions absorbed from the atmosphere when growing plants for biofuels, or emissions that are avoided by diverting waste products to be used as fuels.
These emissions savings are counted towards the UK’s aviation sector as a whole.
(The government says that, for the time being, it will not support SAFs made directly from crops, which tend to have relatively high carbon footprints due to changes in land use.)
The new UK mandate starts in 2025 with a requirement that 2% of total jet fuel demand is SAF, increasing to 10% in 2030 and 22% in 2040. The government says there is currently not enough certainty in the SAF market to set targets beyond that date.
These measures will cut overall aviation emissions by 2.7MtCO2e in 2030 and 6.3MtCO2e in 2040, according to the government.
Based on government forecasts for jet fuel use, this change will be almost totally offset by a growth in flights, leaving UK aviation emissions virtually unchanged between now and 2040.
Emissions in 2025 are expected to be 36.0MtCO2e, while 15 years later they are set to be 35.7MtCO2e, according to Carbon Brief analysis. This is a drop of just 0.3MtCO2e, or 0.8%. This is illustrated in the chart below, with the SAF mandate merely preventing an increase in emissions resulting from higher jet fuel use in 2040.
These figures are derived from the government’s “central case”, cited in its underlying analysis for the SAF mandate, which sees jet fuel use increasing from 11.5m tonnes (Mt) in 2025 to 13.3Mt in 2040. This, in turn, is based on policies in the government’s “continuation of current trends” scenario, with the SAF mandate included.
The government expects far more flights to take off from the UK in the coming years, resulting in higher jet fuel use. It has resisted pressure to curb the demand for air travel, despite warnings from experts that such actions are vital for reducing aviation emissions.
In its jet-zero strategy, the government stated that it is aiming for a “high ambition” scenario, which would see aviation emissions fall faster in the coming years. However, as it stands, it has not introduced policies to drive further emissions reductions in planes.
The SAF mandate assumes that SAFs reduce lifecycle emissions from jet fuel by 70%. Certificates will be issued to fuel suppliers for each tonne of SAF produced, using this baseline emissions reduction goal as the standard.
However, Prof Bill Rutherford, an Imperial College London biochemist who contributed to two major assessments of low-carbon aviation fuels in the UK last year, tells Carbon Brief he is sceptical about lifecycle emissions analysis that shows such high emissions benefits:
“Lifecycle analysis is a very fuzzy science…You can basically get what you want out of it.”
For example, in its analysis, the government assumes that SAFs made from used cooking oil – which are expected to make up virtually the entire UK supply in the short-term – cut lifecycle emissions by roughly 95-98% compared to conventional jet fuel.
Dr Andrea Fantuzzi, another Imperial College London chemist who also worked on the low-carbon fuel assessments with Rutherford, says such figures seem “way too high”. He estimates that the savings would be closer to 70%.
Fantuzzi adds that even this does not account for the land originally used to produce the oil, and assumes that the oil would otherwise be thrown away – rather than used to power road vehicles, for example. (For more on waste oils, see: More cooking oil.)
Additionally, Rutherford points out that the use of SAFs has no impact on non-CO2 emissions from planes, which could account for up to two-thirds of their climate impact. He concludes:
“The only way you can make aviation any more sustainable is to do less of it.”
More cooking oil
The only SAFs that are currently available in the UK are fuels made from used cooking oil and other waste oils, which are collected from restaurants and factories.
However, the SAF mandate includes a limit on the amount of waste oil-based fuels within its overall targets. This is partly to “incentivise the development of new technologies” and partly due to concerns that waste oil supplies will be insufficient.
For the first two years, these fuels will be allowed to make up 100% of UK SAFs. This then falls to 71% in 2030 and 33% in 2040. Overall, waste oil-based SAFs would account for 2% of total jet fuel use in 2025 and up to 7.8% in 2040.
Despite these limits, waste oil-based SAF use is expected to rise around 15-fold from current levels within a decade. This huge increase in demand for waste cooking oil under the SAF mandate is illustrated in the figure below.
The Aviation Environment Federation said in a statement that the amount of waste oil being allowed into UK jet fuel under the UK’s SAF mandate is “much higher than we, and many others, were expecting, and appears to be the result of airline pressure”. The looser cap on these fuels was “welcomed” by industry body Airlines UK.
It raises the question of where the UK will source the required volume of waste oil to meet SAF targets.
Studies have shown that there is nowhere near enough waste cooking oil produced domestically, within the UK, to supply jet fuel demand. “We’re not about to start eating more chips, so we will have to start importing more waste oil,” Matt Finch, UK policy manager at the NGO Transport and Environment, tells Carbon Brief.
The government itself acknowledges this, saying that production of these SAFs within the UK is likely to be constrained by the availability of waste cooking oil from 2029 onwards.
It notes that their availability will therefore be “highly dependent” on how much waste oil the UK can import.
As of 2023, waste cooking oil collected in the UK only accounted for 7% of the country’s SAF production. This share has shrunk in recent years, such that imports from other countries – particularly China – have driven most of the growth in production, as the chart below shows.
There is mounting evidence that the demand for imported cooking oil in the UK and Europe is being met with virgin palm oil that has been fraudulently passed off as waste. This would cancel out the fuel’s emissions savings, due to the land clearances for oil palm plantations.
The UK’s aviation sector will have to compete not only with other countries for a limited pool of waste cooking oil, but also with other sectors.
Most of the UK’s waste cooking oil supplies are currently used to make biofuels for trucks and other road transport. Again, diverting resources from road fuel use would undermine the emissions savings from using them in SAFs.
The government acknowledges this, noting that “the SAF mandate may divert feedstocks which would have been utilised in other sectors of the economy and this may increase emissions in other sectors”. However, it says this is justified because “there are limited alternatives to decarbonise aviation by 2050”.
One of the scenarios modelled by the government assumes that SAF targets are met, but insufficient waste cooking oil means there is not enough biodiesel for road vehicles. This reduces the cumulative emissions savings between 2025-40 from 53.9MtCO2e to 43.0MtCO2e.
New fuels
The government is also supporting new types of SAF production in the UK, including fuels made from “black bin bag waste” and residues from farming or forestry.
In the newly released documents, the government says the UK will be a “leader” and a “first mover” in these technologies, spurred on by the cap on waste oil fuels and supported by the Advanced Fuel Fund.
Unlike waste oil-based fuels, the government says there will be “sufficient” materials available to meet production demand for these advanced fuels until at least 2040. From that point onwards, it says lack of materials “may become a constraining factor”.
However, a 2023 report by the Royal Society highlighted the limited availability of some waste materials to produce SAFs. It estimated that forest offcuts, for example, would be able to provide no more than 1.7% of current jet fuel demand.
Moreover, many waste sources are already recycled or burned to generate electricity and the government has targets in place to cut household waste in the coming years. “Most waste is already used for something that’s not jet fuel, so we know supplies of waste-based SAF will be limited,” Finch tells Carbon Brief.
Finally, the government’s mandate also includes another target, within the overarching SAF goal, for scaling up the production of “power-to-liquid” fuels.
These fuels can be made using green hydrogen and carbon captured from the air. Unlike most SAFs, they could cut up to 100% of CO2 emissions compared to conventional jet fuel, but they are currently less developed than other options.
The target for power-to-liquid fuels will start in 2028 at 0.2% of total jet fuel demand, reaching 0.5% in 2030 and 3.5% in 2040.
These targets are lower than the ones introduced in the EU, which is aiming for 35% of its jet fuel to be power-to-liquid by 2050. The bloc is also targeting 70% of aviation demand to be met with SAFs by 2050, whereas the UK’s targets stop at 22% by 2040.
In its “balanced net-zero pathway” for UK aviation, government advisors the Climate Change Committee (CCC) proposed that SAFs should make up 25% of jet fuel by 2050, with one-third of this made up of power-to-liquid fuels – roughly 8% of total jet fuel. The government targets are roughly in line with this trajectory.
Thinktank Green Alliance laid out three scenarios for SAF expansion in 2022, including higher ambition goals, with power-to-liquid fuels reaching 28% and 50% of total jet fuel by 2050.
However, it noted that such a rollout could be constrained by the large amounts of additional green hydrogen and renewable power required to produce these fuels.
The report stated:
“It could be argued that aviation should not be a priority use of renewables as there are other options to cut carbon in the sector, such as managing the number of flights taken.”
The post Analysis: Benefits of UK ‘sustainable aviation fuel’ will be wiped out by rising demand appeared first on Carbon Brief.
Analysis: Benefits of UK ‘sustainable aviation fuel’ will be wiped out by rising demand
Aviation is on track to be responsible for 80% of the UK’s carbon dioxide (CO2) emissions by 2050, according to the Climate Change Committee (CCC).
Emissions from flying have more than doubled since 1990 – driven by rising passenger numbers – even as the climate impact of every other sector in the UK economy has fallen.
The UK does not have “credible” policies in place to reverse this trend of rising emissions, says the CCC in new advice to the government on future aviation policy.
The government has signalled its support for expanding Heathrow, the nation’s largest airport, while relying on “techno-fixes” such as “sustainable aviation fuels” (SAFs) to cut emissions.
Yet, even without Heathrow expansion, the CCC says aviation emissions are on track to be higher in 2050 than they are today – reaching 38m tonnes of CO2 (MtCO2).
As the chart below shows, this would account for most of the remaining CO2 from the UK economy, all of which would need to be removed from the atmosphere in order to meet the legal target of net-zero emissions.
Expanding Heathrow would add another 2.4MtCO2 in 2050, amounting to around 5% of all the UK’s emissions. (This would increase to 4.5MtCO2 when expansion is complete in 2054.)
With a final decision on Heathrow expansion expected by 2029, the government asked the CCC for its advice on whether the plan is compatible with the UK’s climate targets.
The CCC has concluded that the UK simply lacks sufficient policies to reduce aviation emissions and “expanding Heathrow would compound the problem”. In a press briefing, CCC chair Nigel Topping told journalists:
“The UK does not currently have a credible plan to reduce [aviation emissions] in line with net-zero, so that creates a serious challenge for meeting our climate commitments.”
The “jet-zero strategy”, launched by the previous Conservative government in 2022, set out plans to cut aviation emissions. However, the Labour government has since accepted that the strategy’s expectations for SAFs, electric planes and fuel-efficiency improvements were unrealistic.
The CCC says a “credible and robust net-zero policy framework for aviation” should be set out in a revised strategy, which is planned for 2027. Only then could Heathrow expansion be aligned with the net-zero goal, adds the committee.
As part of this new strategy, the CCC says the “aviation sector needs to take responsibility for its emissions”. It says policies should be designed based on the “polluter pays” principle, requiring the aviation industry to fund its own SAFs and CO2 removal.
Specifically, the committee says funding will be needed for “engineered removal” technologies, such as direct air carbon capture and storage (DACCS).
These technologies are currently “not yet available at the scale required”, but are vital for the kind of permanent CO2 removal needed to mop up aviation emissions, says the CCC.
(“Natural solutions” such as tree planting are the other main way CO2 is expected to be removed from the atmosphere. However, the CCC envisages these removals offsetting the remaining methane emissions from livestock agriculture in the UK, whereas it says “engineered removals” would be required to remove and store CO2 from flights.)
The CCC acknowledges that placing decarbonisation costs on airlines would likely lead to higher ticket prices. It estimates that this could mean an increase, in 2024 prices, of around £150 for a return trip to Alicante, Spain, and £400 for a return trip to New York by 2050.
However, it says this is preferable to a public spending approach, which would result in the roughly 50% of the population who do not fly paying for flight-related CO2 removals.
In addition, the committee notes that higher costs would help to manage demand for flights, which would otherwise be expected to increase considerably over the coming decades.
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The post CCC: Heathrow expansion could push flights to ‘80% of UK emissions by 2050’ appeared first on Carbon Brief.
CCC: Heathrow expansion could push flights to ‘80% of UK emissions by 2050’
A fifth of the world’s greenhouse gas emissions are linked to international trade in goods and services, a new tracker shows, spotlighting a little-studied issue that researchers say should be tackled by the UN climate process.
Currently, as part of the Paris Agreement, every country is responsible for counting and reducing the planet-heating emissions that are produced within its territory. Manufacturing countries, for example, may have high emissions even if what they make is exported for consumption elsewhere.
But new analysis from the European Climate Foundation (ECF) and climate consultancy Matière, based on the tracker’s data, shows that some countries have a high footprint of “imported emissions” from goods and services they ship in. These emissions are often ignored in the places where the products are consumed because they are not formally counted under greenhouse gas inventories.
In the European Union, for example, while domestic emissions have declined since 2015, imported emissions have remained unchanged, the analysis shows. In some countries, like Austria or Sweden, they are as high as the country’s entire annual carbon footprint.
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Former EU lead climate negotiator Jacob Werksman said that under the Paris Agreement, these traded emissions are accounted for in the countries where they are originally produced, but importing countries can also take responsibility for their consumption.
“It starts with a wide recognition by many jurisdictions around the world that we need to know the carbon content of these products, and we then need to agree what is a fair, effective, transparent and relatively easy-to-implement way of measuring that carbon in traded products,” he told a launch event for the trade emissions tracker, which contains data for different countries, sectors and gases.
Trade and its role in addressing climate change has become a higher priority at UN climate talks after a push led by emerging economies including China, India and South Africa led to the first trade and climate change dialogue held this year at the mid-year session in Bonn.
At the upcoming COP31 UN summit in Antalya, some voluntary initiatives like the Brazil-led Integrated Forum on Climate Change and Trade are expected to continue, but the issue does not feature in Türkiye’s Action Agenda of climate initiatives and formal negotiations are not scheduled on the topic.
China: the world’s top emissions exporter
As a manufacturing powerhouse, China ranks first in the new tracker as the world’s top-emitting country, but the data shows that a large chunk of the country’s carbon emissions – an amount larger than Brazil’s entire annual carbon footprint – are linked to products that are exported and consumed abroad.
Russia, Brazil, the US and the EU rank as the top destinations for Chinese trade-related emissions, which are mostly linked to components for power generation, basic metals like copper and lead, and non-metallic minerals like graphite and phosphorus.
Yet China is also the world’s top emissions importer, related mostly to agricultural products, fossil fuels and minerals brought from the US, the EU, Japan and India, among others. The US ranks second by a close margin, with both countries importing about 1.6 billion tonnes of CO2 equivalent.
China’s industrial engine starts to break its fossil fuel habit
Richard Baron, ECF’s industrial policy and trade director, said Chinese clean energy products are key for reducing emissions around the world, adding that Europe is “not able to do without those technologies” for its energy transition.
“China has an emissions trading system that counts CO2 differently there. But if China and the EU were to agree on some kind of translation mechanism to say ‘this is how we measure it’, and companies can understand the protocol to navigate both markets, that would set the tone for a lot of other conversations,” he said at the platform’s launch event last week.
The analysis suggests that if the EU and China aligned their climate requirements for products, the resulting standards could influence trade flows representing about 7% of global emissions.
Baron said there’s “a plethora” of multilateral spaces to hold these discussions, including the climate and trade dialogue at the UN climate talks or the Climate Club at the Organisation for Economic Co-operation and Development (OECD), which seeks to cut industrial emissions.
Trade breaks into agenda of UN climate talks – but will it have teeth?
Controversial trade measures
Instruments like the Europe’s Carbon Border Adjustment Mechanism (CBAM) – a recent piece of legislation that penalises emissions-heavy imported products – are one tool that could be used to address trade-related emissions, said Antoine Oger, executive director at the Institute for European Environmental Policy.
He said a significant portion of imported emissions in Europe are already covered by CBAM, as it includes sectors like cement, iron and steel, fertilisers and aluminium. This then allows the EU “to engage in constructive dialogue with our trade partners”, he added.
But across diplomatic summits, including at UN climate talks, emerging economies have pushed back heavily against the CBAM and other trade measures. The most recent BRICS declaration adopted on Saturday by 11 such countries – including China, India and Russia – condemns “protectionism under the guise of environmental objectives”.
The declaration calls for the “elimination of such unlawful measures”, which they argue have “far-reaching negative implications for the human rights, including the rights to development, health and food security” of vulnerable communities.
“The question of responsibility is a political question,” Oger said. “These emissions exist – they are emitted somewhere to make a product that will be consumed elsewhere. So you can debate responsibility but the idea is for the two parts to recognise there’s a problem.”
The aim, he added “is not to point fingers, but to accept this is a reality of our emissions profiles and ask what we can do about it”.
The post International trade linked to 20% of global emissions – but imports ignored appeared first on Climate Home News.
International trade linked to 20% of global emissions – but imports ignored
All the ambulance services in England experienced some of their busiest-ever days during this summer’s record-breaking June heatwave, according to data obtained by Carbon Brief.
In June, temperatures climbed past 37C in parts of the country as authorities declared only the second ever “red” extreme heat warning.
Four out of 10 NHS ambulance services, including London’s, responded to unprecedented numbers of life-threatening emergencies on at least one day from 23-27 June.
Another two services – in the south-west and east of the country – received their highest volume of 999 calls on record.
Ambulance services provided data on their busiest days since records began, in response to freedom-of-information (FOI) requests from Carbon Brief.
The results show how demand during the June heatwave exceeded levels seen during the traditionally busy winter season in other years – and even the height of the Covid-19 pandemic – for many services.
Heat demand
Extreme heat ramps up the risk of numerous life-threatening conditions, including heart disease and respiratory problems.
England experienced record-breaking temperatures at the end of June, with the whole country covered by amber or red “heat health alerts” from the government.
A red alert, which was issued for the entire Midlands and south of England, indicates “significant risk to life for even the healthy population”. This was only the second time such an alert has been triggered.
Researchers calculated that there were nearly 3,000 heat-related deaths in the UK this summer. There has also been unprecedented demand for A&E departments and some ambulance services.
To investigate the strain facing ambulances, Carbon Brief sent FOI requests to the 10 NHS ambulance trusts in England, asking for lists of their busiest days.
This covered both the total volume of 999 calls and “category 1” responses – referring to incidents involving “life-threatening injuries and illnesses”, such as heart attacks.
The chart below shows the busiest days on record for England’s ambulances, including both total calls and category 1 responses. Most services were able to provide records back to the 2010s. (See: Methodology.)
The five-day period from 23-27 June is overrepresented in these results, with at least two heatwave days ranking in the top 20 for every service in the country.
This trend is especially pronounced in the south and east of England, where June temperatures exceeded 36C and even approached 38C in some regions.
London, South East Coast, South Central and North East ambulance services all reported daily records for responding to life-threatening emergencies during the heatwave.
For the South East Coast and South Central services – which cover a region stretching from Oxfordshire to Kent – 25, 26 and 27 June all saw unprecedented numbers of category 1 callouts.
South Western and East of England services both saw record numbers of 999 calls on 26 June, the same day the highest-ever June UK temperature was reported in Norfolk.
It is worth noting that demand for ambulance services – including category 1 calls – has been growing for many years, driven by factors such as an ageing population, more complex health conditions and growing mental-health pressures.
This helps to explain why dates from before the 2020s are rare in the top rankings provided to Carbon Brief.
Beyond the heatwave, 2026 as a whole is on track to be a record year for ambulance demand.
‘Stifling heat’
On 26 June, the busiest day of the heatwave, ambulances across England responded to 4,084 life-threatening emergencies.
The average daily volume of such incidents is normally around 2,500 during the summer months.
Stu Holliday, head of emergency preparedness, resilience and response at North East Ambulance Service, tells Carbon Brief:
“During periods of hot weather, we typically see an increase in calls from people affected by dehydration, heat exhaustion and heatstroke, as well as those whose existing health conditions, particularly heart and respiratory illnesses, can be made worse by prolonged high temperatures.
“Older people, young children and pregnant people can be especially vulnerable.”
Ambulance teams are generally busier in the winter because cold weather and seasonal illnesses drive up the number of severe medical emergencies.
However, the data from June shows that extremely hot days are starting to match or even edge out cold ones as the busiest days. This is a trend seen across the healthcare system.
While not every service provided records back to 2019, the data broadly shows that ambulances were busier during the heatwave than at the height of the Covid-19 pandemic.
As well as patients, heatwaves put pressure on ambulance workers. The UNISON union has warned of crews facing “stifling heat with faulty or no air conditioning” and “back-to-back callouts” due to increased demand.
Methodology
Carbon Brief requested data on the top 50 busiest days for England’s 10 main ambulance services.
These are: London; South East Coast; South Central; South Western; West Midlands; East Midlands; East of England; North East; Yorkshire; and North West.
Data was requested for as far back as service records go. Most were able to provide records going back to some point in the 2010s, with the exception of North East and South Central, which only had records from 2021 and 2022 onwards, respectively.
Rising annual demand for ambulance services means that most of the busiest days for ambulances have been in the 2020s. For example, all but four of the busiest days for category 1 emergencies reported to Carbon Brief were in the 2020s.
Carbon Brief requested data on ambulance demand for all the UK nations. In Scotland and Northern Ireland – where temperatures are cooler – services did not see call volumes reach the top 50 rankings during the June heatwave. The Welsh Ambulance Service did not respond to Carbon Brief’s request.
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The post Revealed: England’s June 2026 heatwave sparked record demand for ambulances appeared first on Carbon Brief.
Revealed: England’s June 2026 heatwave sparked record demand for ambulances
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