Amid heightened concern last winter about the security of the electricity supply across the island of Great Britain, National Grid Electricity System Operator (ESO) brought in a first-of-its-kind demand-management system.
The Demand Flexibility Service (DFS) relied on consumers reacting to notifications from the operator to help reduce their demand and keep the island’s grid secure during times of particular strain. (The island’s grid incorporates England, Scotland and Wales, but not Northern Ireland.)
Over the course of the winter of 2022/23, the system-level impact of DFS was significant, reducing demand by 2.92 gigawatt hours (GWh) from times of grid strain, according to a recent report from the Centre for Net Zero.
This is equivalent to the electricity needed for every person in Great Britain to make a large cup of tea, it claims.
This helped ensure, it adds, that the ”lights stayed on” and reduced the need for reliance on coal-fired power stations or exceptionally expensive alternatives. Additionally, 681 tonnes of carbon dioxide (tCO2) emissions were avoided through the use of DFS.
ESO has reintroduced the service for 2023/24, with the first session taking place on 16 November.
The Q&A below examines what the service has achieved – and whether it offers value for money.
- What is the ‘demand flexibility service’ and why was it created?
- Who took part in last year’s trial of the service and why?
- What did the demand flexibility service achieve?
- Did the demand flexibility service offer value for money?
- What will the service look like in winter 2023-24?
What is the ‘demand flexibility service’?
In 2022, ESO launched its new DFS to provide an additional mechanism to support energy security over the winter.
There was heightened concern about the potential of blackouts over the winter of 2022/23, due to the volatility in the gas market, exacerbated substantially by the Russian invasion of Ukraine earlier that year.
As such, in its Winter Outlook report, the operator added new tools in the form of securing contingency contracts with coal-fired power plants and launching DFS.
From 1 November 2022, DFS started to incentivise users to reduce consumption during key times, to reduce the overall demand across the system.
Households with a smart meter or business sites with half-hourly metering were eligible to sign up to the scheme and could sign up through either their supplier or a technology provider. In total, there were 31 providers that registered by the end of the DFS period in March 2023.
This was made up of 14 “domestic only”, 10 “non-domestic only” and seven “both domestic and non-domestic”.
DFS was designed so that the ESO could notify providers about the times when capacity on the grid was expected to be tight, allowing them to reach out to their customers who had signed up to the scheme. They could then opt-in to the DFS sessions and work to reduce their demand during the specified periods.
Over the winter of 2022/23, there were 20 test events – which were used to “onboard” providers – and two live uses of DFS, where it was used to ensure there was sufficient capacity to meet demand. These sessions had a duration of 60, 90 and 120 minutes.
Across the test events, ESO established a guaranteed “acceptance price” of £3,000 per megawatt hour (/MWh) for all bids submitted by DFS providers. This was designed to offer assurance to providers.
During the live events, DFS providers presented bids at higher prices than the guaranteed acceptance price, allowing them to incentivise participants further and, therefore, provide more substantial demand reductions during times when balancing the grid was particularly challenging.
The two live events – which took place on 23 and 24 January 2023 – saw providers submit bids within the range of £3,300/MWh and £6,500/MWh, according to data from LCP Delta.
Who took part in last year’s trial of the service?
Between November and March, 1.6m households and businesses participated in DFS, according to the ESO.
Collectively, they provided ~350MW of flexibility during events, helping to avoid blackouts during periods of particular constraint on the grid.
According to a survey conducted by the system operator, a wide range of households took part in DFS. Of those surveyed, 30% had a health condition or long-term illness, 18% were tenants and 30% lived in households with three or more people. This highlighted the low barriers to participation of DFS, according to ESO.
There were still groups that were underrepresented, including younger age groups, lower income households, renters and city residents.
According to ESO’s survey, those under the age of 45 were underrepresented in DFS participation in comparison with the British population. (Britain’s electricity system covers England, Wales and Scotland, therefore, the population of Northern Ireland was not eligible to take part in DFS.) The most pronounced underrepresentation was seen in those aged 18-19 and 20-24 years old. The most overrepresented age groups were 55-64 and 65-74.
Within the under-45 age group, women made up the majority of participants, whereas in the over-45 group men made up the majority. Overall, 54.9% of those surveyed identified as female, in comparison with 51.7% of the British population, the survey continues.
The white ethnic group was overrepresented, with 95.7% of respondents falling within the category, notes the ESO, compared to 82.7% of the British population (a 13% difference).
All other groups were underrepresented, with Asian or Aisan British the most severely so, with only 2.4% of respondents compared to 8.7% of the British population (6.3% difference).
The majority of participants took part for the financial benefits, be they savings or rewards. Of those surveyed by ESO, 76% selected this as their main motivation.
Beyond this, 41% of households were motivated by the challenge of responding and 37% by balancing the grid.
The actions taken by participants to reduce demand varied, with the majority (three-in-four) shifting demand, according to the Centre for Net Zero’s research. For example, shifting the times they used high-load appliances, such as heating or ovens, by an hour, to avoid the DFS session.
Around one-in-two participants reported “demand destruction” in at least one event, according to the research. This is where the demand is completely removed – for example, households who chose to go for a walk instead of putting on the television and did not subsequently watch an extra hour of television later to make up for it.
The Centre for Net Zero’s research found that 17% of participants manually switched off appliances, while the rest scheduled them to either come on before or after the event.
What did the demand flexibility service achieve?
Overall, DFS was considered a success, delivering a total of 3,300MWh of electricity reduction across the 22 events, according to ESO. This is nearly enough to power 10m homes for an hour during peak times across the island of Great Britain.
Through demand reduction, DFS is considered to have avoided a total of 681tCO2.
Great Britain was spared blackouts over the winter of 2023/24 – while services such as DFS played a role in helping to keep the grid balanced and secure during this time. Favourably warm weather, among other factors, also played a role.
Additionally, DFS provided financial benefits to participants. For example, CUB, a family-run commercial energy and utilities consultants business, introduced the CUB Reduction Reward Scheme, allowing its customers to participate in DFS.
In a case study released by ESO, it highlighted that throughout six events, there was an average of 86 businesses taking part in each through the CUB Reduction Reward Scheme. Participants ranged from using 14,000 kilowatt hours (kwh) to 14,000,000kwh per annum.
As of 30 January, participants had earned £34,025, with one business earning £1,726 in one event. Over these events, CUB delivered 12MWh of energy reduction, and avoided 945kg of carbon emissions.
With regard to the domestic market, 13 sessions were offered to 1.4m Octopus Energy customers over the course of last winter, via financial incentives. Overall, the company’s “Saving Sessions” resulted in a reduction in energy demand of 12-25%.
The trial also managed to answer several questions around the potential of demand schemes and the challenges they may face.
For example, the impact of cold weather on the willingness of participants to reduce their demand was an area in need of data, with heating being one of the easier and more common energy uses to turn down during DFS sessions.
Those who opted into Octopus’s Saving Sessions on cold winter days provided a “mean average turndown” of 0.2kW, a similar level to mild or warm days. If this was scaled to the UK’s 30m households at the same rate of participation (one-in-three), the company estimates that would equate to around 2GW of consumer flexibility on cold winter days.
This is roughly equivalent to the entire capacity of Britain’s contingency coal power plants.
Did the demand flexibility service offer value for money?
Overall, ESO paid households and businesses nearly £11m to reduce their power use during the DFS period of 2022/23.
As such, the average cost per megawatt hour of reduced electricity was around £3,330/MWh across the 22 sessions. While this is relatively high, it is also reflective of the scarcity of the use of the service. This is not a cost paid out consistently, but only in the tightest of periods where the alternative options were expensive fossil-fuel generators.
During the same winter, some gas-fired power plants cost up to £6,000/MWh, for example.
Across the two live events, ESO paid more than £3m to suppliers, split between around £850,000 during the shorter event on Monday 23 January and £2.1m for the longer session on Tuesday 24 January.
These arguably provide a clearer picture of what this service could cost in the future, given they allow suppliers to bid what they are happy to pay as opposed to the guaranteed price offered during the test sessions.
For example, during the first live session on Monday 23 January, 400,000 customers participated and were given £3.37/kWh of electricity demand they reduced. Customers were offered £4/kWh on Tuesday 24 January, as ESO accepted a higher bid.
By contrast, ESO’s other additional measure for the winter of 2022/23 was to contract five coal units to stay online under contingency contracts. This was estimated to cost between £340m and £395m, subject to the procurement and use of the coal.
While the coal units were “warmed” six times, according to the Centre for Net Zero’s research, they were not ultimately used. ESO paid approximately £6,000/h to the plants that were warmed, in order to synchronise them with the grid frequency.
ESO has not contracted them for the coming winter.
DFS cost approximately £10.5m in total meaning 2.7% of the capacity payments were spent on the contingency coal contracts.
The Centre for Net Zero’s research, completed a welfare analysis to explore what the marginal social benefits of the policy were with regards to the net cost to the government.
In doing so, it found Octopus’ Saving Sessions demonstrated a marginal value of public funds (MVPF) – which is calculated by dividing the beneficiaries’ willingness to pay by the net costs of the policy – of between 1.05 and 2.6.
This metric shows that the welfare impacts of DFS are sensitive to the extent to which demand response reduces the likelihood of “lost load”, namely, the security of the electricity supply. If it is considered to have reduced the likelihood of a blackout, the MVPF is high, with 2.6 larger than many other popular policy programs, such as housing vouchers, job training, cash transfers, and adult-health subsidies, according to the Centre for Net Zero.
The report notes that during DFS events – when the grid was particularly strained – a marginal unit of electricity would have been sourced from a carbon-intensive gas or coal-fired power plant. These would incur a “marginal private cost” of £835/MWh on average for the ESO, with a maximum of £5,500/MWh, plus the social cost of continued fossil fuel reliance.
It is a difficult balance for the operator to ensure the service offers value for money, while paying consumers enough to make participation attractive.
Lucy Yu, the Centre for Net Zero’s CEO, tells Carbon Brief:
“The DFS is one of the biggest innovations the grid has seen in years. Our analysis shows consumers can offer gigawatt-scale flexibility, at good value for public money. This value exceeds policy spending in areas such as adult education, healthcare and housing.”
According to figures from Octopus in January, the average saving for a household was 23p for each test event. Some participants saved up to £4.35 for each session.
During the first live test, the largest savings seen by domestic users were about £8.75 for the hour.
The supplier estimates that a customer that reduced its demand by 1kWh during 25 events at an average of £4/kWh – as seen in the second live event – could save £100 over a winter.
What will the service look like in winter 2023-24?
DFS has been reintroduced for winter 2023/24. It began on 1 November, with the first test event taking place on 16 November. The first live event has now been announced for 29 November.
As with last year, ESO will run 12 incentivised test events that consumers and businesses can participate in. A guaranteed acceptance price of £3/kWh will be on offer to suppliers, aggregators and businesses for at least six of the test events.
According to the surveys conducted by the Centre for Net Zero, 92% of customers were “very interested” in continuing to participate in future sessions year-round.
DFS remains in a trial stage, with lessons yet to be learnt before it could be truly integrated into the ESO’s system stability services. As such, there are a number of changes made to this year’s service, including the lead time given by the ESO, changes to metering requirements and the ability for providers to make the service “opt-out” rather than “opt-in”.
While the DFS is currently only used to reduce demand, there is also the potential that such a system could be used in the future to manage periods of high generation on the system.
For example, during a period of low demand, such as in the middle of the night, when there is high wind generation. Currently, wind generation has to be “curtailed” to protect the system if there is more generation than demand. DFS could be used to increase demand to take advantage of such periods.
Of those surveyed by the Centre for Net Zero, 81% said they were interested in using more energy to avoid curtailment.
Yu tells Carbon Brief:
“As the energy system evolves to optimise demand closer to real-time, it is important to understand the role schemes such as the DFS might play – including as an important contingency resource targeted at times and locations where it is needed most.
“In the near term, it is a critical tool that allows us to raise consumer awareness of demand response, scale flexibility behaviours and deliver meaningful value to both the grid and households, transforming the relationship between the two.”
The post Q&A: How Great Britain’s ‘demand flexibility service’ is cutting costs and CO2 emissions appeared first on Carbon Brief.
Q&A: How Great Britain’s ‘demand flexibility service’ is cutting costs and CO2 emissions
Four Ugandan farmers filed a case with London’s High Court on Tuesday, aiming to stop the East African Crude Oil Pipeline (EACOP) from starting to operate by asking the court to apply Uganda’s laws against the project’s UK-registered company.
The controversial 1,443-kilometre (897-mile) pipeline, majority-owned by French energy company TotalEnergies, aims to carry crude from Ugandan fields for export through neighbouring Tanzania. About 80% has been built so far, according to its developers.
The pipeline’s first oil exports are expected as soon as October, according to its developers, and the campaign group Avaaz, which is backing the farmers’ crowdfunded lawsuit, called it “one final chance to stop one of the worst oil pipelines on the planet”.
The claim, filed by London law firm Leigh Day, argues that EACOP Ltd’s role in developing and operating the pipeline breaches Ugandan laws that protect citizens’ right to a clean and healthy environment.
-
Ugandan farmers use British court to try to stop East Africa oil pipeline
The farmers and their lawyers will argue that a UK-based entity linked to the East African Crude Oil Pipeline has breached Ugandan law and construction should halt -
French court rules Total must revise climate plan to account for all emissions
Oil and gas giant TotalEnergies has been given six months by a court to publish a more robust climate plan -
Uganda cites contentious IEA fossil fuel scenario backed by Trump administration
Critics of the African nation’s oil ambitions say referencing the International Energy Agency’s most pessimistic scenario for climate action is a risky policy
One of the claimants, Racheal Tugume, told a press conference she had been displaced from her land due to the pipeline’s construction, which she said had damaged local rivers, wildlife and ecosystems that communities depend on for their livelihoods just as erratic weather linked to climate change takes an increasing toll.
“I am very happy that there are people in countries like the UK who are listening to us, who are behind us and who have come to support us,” Tugume said, adding that she hoped the case would bring justice to communities affected by the pipeline.
Ugandan law in UK court
While the pipeline is a joint venture led by TotalEnergies, with smaller stakes owned by Ugandan, Tanzanian and Chinese national oil firms, it is operated by EACOP Ltd, a company registered to an office in London’s Canary Wharf financial district.
EACOP Ltd did not respond to a request for comment.
The claim appears to be the first attempt to have Uganda’s climate and environmental protections enforced in a foreign court, partly reflecting concerns over whether cases challenging the multibillion-dollar pipeline would get a fair trial in Uganda.
Ugandans living near new oil pipeline let down by compensation programmes
Concerns about access to a fair hearing are among the issues the court will consider when deciding if it should take on the case, said Matthew Renshaw, partner at Leigh Day.
Renshaw said that precedents including the Nigerian oil pollution case against Shell have shown that claims against British-registered companies for harms overseas can be successfully fought in UK courts.
“We are proud to represent the four brave principled individuals,” Renshaw said.
Constitutional protections
The pipeline project has already been subject to repeated lawsuits in several countries, none of which have succeeded. A climate lawsuit filed in Uganda more than a decade ago by a group of young people has yet to conclude. Another at the East African Court of Justice, brought by campaign groups against Uganda and Tanzania, was rejected on procedural grounds last November.
A separate ongoing lawsuit in TotalEnergies’ home country of France – a refiled version of an earlier failed claim – cannot stop EACOP going ahead, but it does seek damages from TotalEnergies for affected communities.
With the newly launched case, Leigh Day’s legal adviser Marc Willers said the claim draws on specific Ugandan laws in a bid to stop EACOP’s operations.
Uganda may see lower oil revenues than expected as costs rise and demand falls
These include the Ugandan constitution, a 2019 environmental law and the National Climate Change Act 2021, which gives Ugandans the right to bring a case before a court in circumstances where anyone or any entity threatens the country’s ability to mitigate climate change.
Stopping a “carbon bomb”
The pipeline, which will link Uganda’s Lake Albert oil fields to Africa’s east coast in Tanzania, has already displaced thousands of people and cuts through the Lake Victoria basin, one of East Africa’s major freshwater systems and a critical water source for around 40 million people.
According to the BankTrack non-profit, when the pipeline is at peak production, it will carry 216,000 barrels of crude oil per day and release over 33 million tonnes of carbon emissions each year. Over its full lifetime of 25 years, it is estimated to release about 379 million tonnes of greenhouse gas emissions across its value chain including construction, refining and product use.
A May 2026 report from Earth Insight also warns that the pipeline and related infrastructure could affect 158 wetlands in Uganda, 11 rivers, 44 protected areas and seven key biodiversity areas while disrupting about 2,000 square km of protected wildlife habitats.
This is why the primary focus of the UK court case is to stop the operation of the pipeline in its tracks, Leigh Day’s Willers said, calling it a “carbon bomb” that would worsen the world’s climate crisis.
Long wait for first hearing
While the purpose of the case is to stop the pipeline from launching operations, Renshaw said it could take about 12 months before the case gets a first hearing and about 18 months before it goes to trial.
Billions unlocked as Green Climate Fund agrees to spend more and save less
The farmers are, however, seeking an injunction to stop EACOP Ltd from proceeding with operations. In the event that shipments begin, the lawsuit will still seek to stop the pipeline from then on, Renshaw said.
“We will be doing what we can to expedite matters but it is possible that EACOP will have started operating the pipeline before the claim is heard. If that is the case, the claim would intend to halt operations from that point. For example, the pipeline may operate for just one year rather than 30-plus, resulting in far less harm,” he said.
The post Ugandan farmers launch UK court case against East African oil pipeline appeared first on Climate Home News.
Ugandan farmers launch UK court case against East African oil pipeline
Climate Change
Cited 7 July 2026: ‘Impossible’ heat | Global ocean record | Climate change and the ozone hole
Welcome to Cited, your essential guide to new climate research.
In the news
‘HEAT ALERT’: At least 25 people died as a “heat dome” smothered the eastern half of the US, reported the Guardian, with more than 20 states under “stifling temperatures more than 100F (38C)”. More than 140 million people were under heat alerts, the outlet said, with dead bodies found in “homes with no air conditioning, outside their residences, on the street and in parked cars”. Analysis by World Weather Attribution (WWA) found that the combined heat and humidity would have been “virtually impossible” without human-caused warming, reported the New York Times.
‘MORTALITY WILL RISE FURTHER’: Meanwhile, extreme heat continued to hit Europe, with Le Monde reporting on temperatures of 40C in France, Portugal and Spain again this past weekend, alongside “devastating” wildfires. Public Health France doubled its preliminary estimate of the “excess deaths” from the extreme heat in late June, from 1,000 to more than 2,000, according to the Guardian. The higher figure was still “probably an underestimate”, the agency said. Analysis published by Carbon Brief put the figure at 2,700 heat-related deaths. A WWA attribution study, covered by Carbon Brief, found that Europe’s June heatwave would have been “virtually impossible” even 50 years ago.
‘BOOST TO GLOBAL TEMPERATURES’: The UN World Meteorological Organization (WMO) “raised its forecast for the rapid emergence of a strong El Niño in the coming months, warning that the phenomenon is likely to drive global temperatures higher”, reported Reuters. A WMO scientist told the newswire that “El Niño conditions have emerged in the equatorial Pacific and there is a remarkable agreement between forecast models that this will be a strong El Niño”.
Research picks
Extremes
- The annual season when “intense” tropical cyclones occur has lengthened by 10-14 days per decade across the world since the 1980s | Nature Communications
- There is an “increasing” and “overlooked” global threat from glacial outburst floods from small lakes | Nature Sustainability
- Female smallholder farmers in sub-Saharan Africa experience crops losses 2-2.5 times greater than male smallholders in periods of extreme heat | Nature Sustainability
Policy
- The summaries for policymakers in Intergovernmental Panel on Climate Change (IPCC) mitigation reports over 2001-22 “have not yet become more solution-oriented while abiding by their policy-neutrality principle” | npj Climate Action
- Two-thirds of countries address inequality in their national pledges under the Paris Agreement – particularly in “countries with lower levels of human development and greater income inequality” | Climate and Development
- To “future proof” the Paris Agreement’s “well-below 2C” limit, it should be interpreted as a median “peak warming” of 1.6-1.8C, rather than a 66-90% chance of staying below 2C | Nature Climate Change
Land sink
- From 2001 to 2015, northern Eurasia absorbed about 0.47bn tonnes of carbon each year – around one-third of the total global land carbon sink | Global Biogeochemical Cycles
- Model simulations of potential land-use carbon emissions out to 2100 show that “deforestation and forest regrowth dominate variability” of emissions, with policy timing and ambition “exerting strong control” | Nature Communications
- Tropical forests are facing an increase in areas that exceed critical temperatures where their “photosynthetic system breaks down” | Proceedings of the National Academy of Sciences
Captured
On 21 June, global average sea surface temperature (SST) reached a record high for the day of the year, according to the Copernicus Climate Change Service (C3S). Daily SST for the global ocean, excluding polar regions, reached 20.86C on 21 June, exceeding the 20.83C reached on the same day in both 2023 and 2024, the C3S said. Global SST has remained at record levels for every day since. The conditions “could indicate the beginning of a new phase, leading, once more, to uncharted territory”, said C3S director Carlo Buontempo.
56 hours and 30 hours
The amount of time that the average lifespan of tropical cyclones in the north-east and north-west Pacific has shortened, respectively, over 1982-2024, according to a study in npj Climate and Atmospheric Science. This shorter lifespan “compresses the time available for weather forecasting and disaster preparedness”, the authors said.
Spotlight
The ozone hole and climate change
As a new “thought experiment” asks whether the hole in the ozone layer could, theoretically, have been identified decades before it was discovered, Carbon Brief explores the interactions between climate change and the ozone hole.
It is now more than 40 years since the discovery of the hole in the ozone layer over Antarctica, detailed in the journal Nature in 1985.
A study more than a decade earlier had predicted that chlorine-based substances – such as chlorofluorocarbons (CFCs) – could lead to the destruction of ozone in the stratosphere.
So, in theory, how early could the ozone hole have been detected?
New research, published in the Proceedings of the National Academy of Sciences, explored this very question.
Study co-author Prof Susan Solomon from the Massachusetts Institute of Technology is a leading atmospheric scientist. In the late 1980s, Solomon and colleagues identified the mechanism behind how CFCs were causing ozone depletion.
The new study is a “thought experiment”, Solomon told Carbon Brief, asking when scientists could have discovered the ozone hole had they had access to modern satellite observations.
“We found that depletion could have been detected as early as 1957 in the tropical upper stratosphere, where natural variability is especially small,” explained Solomon.
This would have been before the use of CFCs became widespread, Solomon added. Instead, early ozone depletion was caused by carbon tetrachloride, a chemical used as a cleaning agent, as well as in fire extinguishers and for producing refrigerants.
For many decades, the ozone hole and global warming have often been confused by the public and the media, Solomon explained:
“It’s common to imagine that because ozone is so important at shielding us from the UV [ultraviolet] light that causes skin cancer, then having less ozone must mean the Earth would warm up.”
For example, in a 1995 editorial, the Los Angeles Times congratulated the Nobel prize-winning chemists who identified the threat of CFCs to the ozone layer. The newspaper noted that these processes “threaten calamitous global warming by damaging the Earth’s protective layer of ozone”.
However, said Solomon, “the Earth is warmed much more by visible light – UV doesn’t really contribute, so ozone depletion doesn’t cause significant warming”.
Regional impacts
The depletion of ozone actually has a very small cooling effect at the Earth’s surface. But this is more than outweighed by the warming impact of CFCs and other ozone-depleting substances.
This warming impact means that efforts to reverse ozone depletion have had a beneficial impact on the climate.
The Montreal Protocol, a 1987 international agreement to phase out CFCs, “has played – and is playing – a very substantial role in safeguarding climate too”, said Solomon:
“It turns out that the CFCs and their replacement gases HCFCs [hydrochlorofluorocarbons] are strong greenhouse gases, so phasing out their production has not only avoided a lot of ozone depletion that would otherwise have occurred, it also had a big influence on global warming.”
HCFCs were considered as “transitional substitutes” for CFCs – they still damaged ozone, but to a lesser extent – until ozone-safe alternatives were commercially available.
Hydrofluorocarbons (HFCs), which are not ozone depleting, began to be used widely in the 1990s. However, HFCs are also potent greenhouse gases. HFCs and similar replacements are now being phased out under the 2016 Kigali Amendment to the Montreal Protocol.
While the ozone hole itself has only a very small impact on global temperatures, it does have a clear impact on the regional climate over Antarctica.
Prof David Thompson from Colorado State University, working with colleagues including Solomon, has published research demonstrating that “changes in southern-hemisphere winds linked to the stratospheric ozone losses extend all the way down to the ground in some seasons”, explained Solomon.
This has “reduc[ed] warming that would have occurred in interior Antarctica and enhanc[ed] warming in the Antarctic Peninsula region”, she said.
The knock-on impacts include “wind changes [that] actually extend beyond Antarctica to the mid-latitudes of the southern hemisphere, where they even affect rainfall”, she added.
Preprints to watch
Carbon Brief’s pick of new papers under review
- The drying impact over Africa from using stratospheric aerosol injections to stabilise global temperatures would only be minimised “when combined with a strong decarbonisation effort” | Earth System Dynamics
- The El Niño-Southern Oscillation and Indian Ocean Dipole could “shape” the playing conditions at the Rugby World Cup 2027 in Australia | Journal of Southern Hemisphere Earth Systems Science
- A “strong” weakening of the Atlantic Meridional Overturning Circulation (AMOC) would “profoundly alter the climate-carbon cycle system”, underscoring the “importance of explicitly accounting for AMOC risks in long-term climate assessments” | Earth System Dynamics
Noticeboard
- 6 July-25 September: Registration open for experts to review the first-order draft of the Intergovernmental Panel on Climate Change’s Working Group I report
- 7-15 July: UN High-level Political Forum on Sustainable Development, New York
- 19 July: Application deadline for a postdoctoral scholar in transdisciplinary climate research at Penn State University, US | Salary: unknown
- 22 July: Application deadline for PhD project on “climate change impacts on the Antarctic coastal ocean carbon sink” at the University of East Anglia, UK
- 26 July: Application deadline for PhD projects on “AI for land-atmosphere feedbacks during hydroclimatic extremes” at the Helmholtz School for Integrated Data Science in Environmental & Life Sciences, Germany
- 29 July: Application deadline for an assistant professor in Earth and environmental geosciences (palaeoclimatology) at Colgate University, US | Salary: $97,500-101,500
- 31 July: Application deadline for PhD project on Arctic Ocean methane oxidation at Stockholm University, Sweden
Cited is researched and written by Cecilia Keating, Robert McSweeney, Ayesha Tandon, Daisy Dunne and Dr Giuliana Viglione.
Please send tips, feedback and upcoming climate research to cited@carbonbrief.org
This is an online version of Carbon Brief’s fortnightly Cited email newsletter. Subscribe for free here.
The post Cited 7 July 2026: ‘Impossible’ heat | Global ocean record | Climate change and the ozone hole appeared first on Carbon Brief.
Cited 7 July 2026: ‘Impossible’ heat | Global ocean record | Climate change and the ozone hole
In June 2026, a record-breaking heatwave swept across Europe, with France among the first and hardest hit countries.
In a new analysis, we estimate that the extreme conditions caused more than 2,700 heat-related deaths in France.
We also show how France’s extreme temperatures in June exceeded projections from climate models.
Our findings illustrate the human toll of extreme weather as the world warms.
We also highlight the challenges in projecting the magnitude of future heatwaves and their impacts on people.
Outpacing projections
For most of this century, Europe has seen summer heat extremes that outpace projections from climate models.
Several different factors likely explain this trend, including reductions in planet-cooling aerosols as nations have cleaned up their air pollution, as well as changes in atmospheric circulation patterns, which models struggle to represent.
In June 2026, daily high temperatures averaged across France reached 36.9C, shattering the previous June record set in 2022 by 2.4C.
[For more on the impacts and coverage of Europe’s June heatwave, see Carbon Brief’s explainer.]
The rise in observed temperatures in France has outpaced projections made by climate models, with June maximum temperatures more in line with what was expected for the 2070s.
This is illustrated in the figure below, which shows how France’s average maximum daily high temperature for June recorded in 2026 (black line) compares to climate model projections (blue and orange lines).
Counting the death toll of climate change
The downstream impacts of these extreme temperatures are lethal.
Scientists are able to estimate the death toll of high temperatures in many locations, depending on the availability of mortality and climate data.
There are several ways to do this.
One option is to examine death certificates to see which deaths have been directly recorded by physicians as related to heat. However, there is strong evidence that this method significantly undercounts heat-related deaths, as most death certificates do not consider environmental factors such as heat when diagnosing the cause of death.
Alternatively, it is possible to calculate the rate of total (“all-cause”) mortality in a given time period relative to previous time periods – for example, by comparing the total number of deaths in June 2026 compared to the average of previous Junes. This “excess deaths” figure can be used as an estimate of the deaths from a heat wave.
Using this approach, Public Health France attributed around 2,000 deaths in France to the extreme heat in the week of 22-28 June.
Finally, scientists can use long-term data on overall mortality and correlate changes in mortality with changes in temperature to understand the statistical relationship between the two.
Research published in Proceedings of the National Academy of Sciences in 2025 that used this third approach found that mortality rates in France increase rapidly in cold or hot conditions as daily maximum temperatures depart further from approximately 20C.
This pattern of a U-shaped response of mortality to temperature – shown in the figure below – is very consistent across time periods and regions around the world.
To calculate the death toll of the June 2026 heatwave in France, we compared observed temperatures over 12-29 June to their baseline average over 1980-2025.
The difference between these two temperatures helps us understand how many more people died than they would have in the absence of such extreme conditions.
Over 12-29 June, we found that France has experienced around 2,700 heat-related deaths above the average baseline. Day-to-day heat-related mortality rates rose from less than 100 to almost 300 on the hottest days of 24 and 25 June.
This is shown in the graph below, which illustrates the cumulative total heat-related deaths seen in France over the two-and-a-half week period. The inset shows how heat-related deaths fluctuated on a day-to-day basis during this time.
Recent analysis by World Weather Attribution has already shown that human-caused climate change increased the frequency and intensity of the June heat wave across Europe.
Meanwhile, previous research has shown there is substantial evidence that heat-related mortality in Europe has already been elevated by greenhouse gas emissions.
As a result, we can be confident that at least some of the more than 2,700 deaths already seen in France are directly due to the burning of fossil fuels.
Calculating climate risk
In April, the UN-led body responsible for coordinating the work of climate modelling centres – the Coupled Modelling Intercomparison Project (CMIP) – unveiled a set of seven new emissions scenarios.
These are designed to replace the previous scenarios that have been used by scientists to understand how the climate might change in the future. They will feed into the upcoming seven assessment report (AR7) of the Intergovernmental Panel on Climate Change (IPCC).
The range of future emissions in the new CMIP scenarios is smaller, with scenarios of very high or very low emissions no longer on the table.
The retirement of the very-high emissions scenario – known as “RCP8.5” – led to certain commentators in the media and in politics, including US president Donald Trump, arguing that the risks of climate change had been “overstated”.
[For more on false and misleading claims around the new emissions scenarios, see Carbon Brief’s factcheck.]
Our analysis of June’s heat-related deaths in France suggests that, even if the most severe emissions pathways are no longer needed, climate impacts are taking a heavy toll on society.
Moreover, the temperatures seen in France show that climate models continue to underpredict the magnitude of heatwaves for a particular level of global warming.
This is because greenhouse gas emissions are only a first step in estimating the impacts of climate change.
The second step is converting emissions to changes in the climate at both the global and local levels – or hazards. This includes heatwaves, flash floods and droughts.
The third step is to determine how changes in the hazards will affect local populations. This can be determined by calculating people’s exposure and vulnerability to hazards.
Substantial uncertainty persists at every stage of this sequence.
For example, scientists do not know exactly how the global climate will react to ever-rising greenhouse gas emissions – nor the extent to which global temperature increases will drive local climate hazards. We also do not know how climate change at a local level impacts human health outcomes.
Managing the future of heat risk
Almost all heat-related deaths are preventable.
Adaptation options, such as air conditioning, heat action plans and social support for isolated people, will be crucial as the climate moves away from the typical conditions that people are used to.
Our previous research showed that France made a lot of progress reducing heat-related mortality after the deadly 2003 summer heatwave by taking many of these actions.
Adaptation can reduce deaths, but it cannot eliminate the risk created by continued warming.
Without a move away from fossil fuels, future heatwaves will keep testing the limits of public health systems and more people will die.
The post Guest post: France’s June heatwave caused more than 2,700 heat-related deaths appeared first on Carbon Brief.
Guest post: France’s June heatwave caused more than 2,700 heat-related deaths
-
Greenhouse Gases11 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Climate Change11 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Greenhouse Gases2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Climate Change2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Renewable Energy9 months agoSending Progressive Philanthropist George Soros to Prison?
-
Climate Change2 years ago
Bill Discounting Climate Change in Florida’s Energy Policy Awaits DeSantis’ Approval
-
Carbon Footprint2 years agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits
-
Greenhouse Gases12 months ago
嘉宾来稿：探究火山喷发如何影响气候预测