Extreme weather events, such as heavy rainfall, flooding and heatwaves, have been described as the “new normal” for China.
The country lost almost 12bn yuan ($1.65bn) due to heavy rainfall and floods in April – “the worst in 10 years”. In June, dozens of people were killed and some 33 rivers in China “exceeded warning levels”. The floods in Guilin, capital city of Guangxi province, were the largest in the area since 1998.
It has been less than a year since the Beijing meteorological service recorded 745mm of rain in just five days during July 2023 – roughly the same amount the city usually receives in the whole month.
The province surrounding Beijing, Hebei, also had heavy rainfall at the same time. In July 2023, the county of Lincheng recorded more than one metre of rain, twice its annual average.
In July 2021, Hebei’s neighbouring province Henan had a “one-in-a-thousand-year” rainstorm.
While China has issued more policies to improve its emergency response system and infrastructure, the increasing number of extreme weather events continues to pose challenges.
In this Q&A, Carbon Brief looks at the reasons for China’s recent floods, how the country is adapting and whether it will need to re-examine and future-proof its flood defence systems.
- What are the reasons behind the recent floods?
- What role does human-caused climate change play?
- How is China adapting to increasingly frequent flooding?
- How effective are these measures?
- What can China learn from other cities?
What are the reasons behind the recent floods?
There are various factors behind the frequent heavy rain and flooding in recent years.
Dr Oliver Wing, honorary research fellow at the school of geographical sciences, University of Bristol, tells Carbon Brief that “on the whole, we expect a warming world to be a wetter world due to the Clausius-Clapeyron relationship”.
This relationship dictates that the air can generally hold around 7% more moisture for every 1C of temperature rise, meaning rainfall is likely to be heavier in a warmer climate.
Wing notes that “for sub-daily rainfall, we are seeing even greater scaling than this relationship would suggest. This makes surface water flooding in cities [more likely] due to short-duration, intense, localised rainfall increase”.
In addition, he says, “warming is inducing a rise in sea levels in most places, meaning storm surges have a higher baseline from which to inflict damage”.
In China, “higher than normal temperatures” were behind frequent heavy rainfall in southern coastal provinces, such as Guangdong and Guangxi, since April, says Zheng Zhihai, chief forecaster at the National Climate Centre of the China Meteorological Administration (CMA), and reported in China Daily.
Zheng adds that the El Niño-Southern Oscillation – a natural climate cycle that entered its warmer El Niño phase in mid-2023 – was partly to blame because it raised sea surface temperatures and directed vast amounts of water vapour from the South China Sea and the Bay of Bengal towards southern China.
Dr Faith Chan, head of the school of geographical sciences at the University of Nottingham Ningbo China, tells Carbon Brief that the rainfall pattern in Guangdong during this April was quite similar to the intensive rainstorm on 6-8 September in 2023 after Typhoon Haikui.
Specifically, the intense rainfalls were generated by the low-pressure moist current from the south-east and south Asian monsoon pattern crashing into another low-pressure rain belt from the Philippines and the west Pacific.
Typhoon Haikui had hit Hong Kong with the worst storm in 140 years and caused some of the heaviest rains in the provinces of Guangdong and Fujian.
While these intense rainstorms, in a meteorological sense, are not unusual, they are happening more closely to one another owing to the warming world, Chan says.
Large-scale heavy rainstorms typically occur three times on average in April – the onset of a monsoon season. But, this year, China has been battered by at least eight regional extreme rain events in the month alone, all happening in quick succession.
River floods are commonly seen in the affected regions, such as Chongqing and Hunan. Identifying the causes can be more complicated for river floods in general, says Wing:
“There are many modulating factors. Drier soils in a warming world may enable the land to absorb the increased rainfall, thereby mitigating any flood hazard increase. Many floods are not driven by intense rainfall, but are driven by snowmelt or low-intensity, long-duration rain falling on saturated soils. For this reason, it is not reasonable to extrapolate that increased rainfall in a warming world will lead to increased fluvial flooding.”
Chan says natural reasons “of course” enhanced the wetness, “but human-induced climate change led to the greenhouse effect and caused sea temperature to rise, which caused more storms and low-pressure rain belts. That is a fact”.
Wing agrees that “the thermodynamic impact” of human-led climate change increases the rainfall associated with storms. But, he adds:
“What we do not understand well is how anthropogenic climate change has altered the dynamics of the climate system, and where and how this either compounds or dampens the thermodynamic response.”
What role does human-caused climate change play?
Many studies have found that warmer sea surface temperatures are supercharging high-impact, back-to-back extreme rains.
The sixth assessment report (AR6) from the UN’s Intergovernmental Panel on Climate Change (IPCC) also says that human-induced climate change caused by greenhouse gas emissions contributes to ocean warming and “is likely the main driver of the observed global-scale intensification of heavy precipitation over land regions”.
In east and central Asia, under 1.5C of global warming, extreme annual daily rainfall (Rx1) and five-day accumulated rainfall (Rx5) events are projected to increase by 28% and 15%, respectively, relative to 1971-2000, according to AR6.
Similarly, it says that in China’s urban agglomerations, “an increase in global warming from 1.5C to 2C is likely to increase the intensity of total precipitation of very wet days 1.8 times and double maximum five-day precipitation”.
Prof Yang Chen of the Chinese Academy of Meteorological Sciences at the CMA tells Carbon Brief that human-caused intensification of heavy rainfall over China had been even larger than expected. He explains:
“Human-caused intensification of heavy precipitation over monsoonal China is markedly larger than expected from increases in atmospheric moisture due to warming, because of stronger feedback between latent heat releases and ascending motion within wetter storms in a warmer climate.”
Such feedback, he adds, is particularly evident in eastern China compared to other regions of similar latitudes.
A recent study in Nature also anticipates storm activity over China to become more frequent and intense as a result of warming. By the end of the 21st century, the annual average frequency of tropical cyclones on the east coast of China is anticipated to increase by 16% compared to the present day, according to the study.
Apart from climate change that is caused by human activities, poorly designed and constructed cities, as well as subsidence – caused by groundwater extraction, the weight of buildings as result of urban growth, urban transportation systems and mining activities – could also amplify floods.
Dr Kevin Smiley, assistant professor from the department of sociology of Louisiana State University tells Carbon Brief:
“Climate change is increasing the severity and frequency of extreme weather. Extra rainfall induced by climate change can be the difference between a building’s parking lot hosting puddles on a rainy day compared to floodwaters crossing the threshold of the building and causing thousands of dollars of damages.
“It’s always important to remember: climate change is anthropogenic, so this increased risk also has human-caused roots.”
How is China adapting to increasingly frequent flooding?
China has built a number of large water projects to prevent flooding, such as the south-north water transfer projects in the Yangtze river that was launched in 2002.
In the most recent “national water network construction planning outline” published by the State Council – China’s top administrative authority, the equivalent of central government – constructing “national water networks” by 2035 is among the “backbones” of future flood prevention.
The “backbones” in the document also include large hard-engineered structures on the main rivers, such as embankments, flood gates and channelised river networks, to mitigate flood risks.
Meanwhile, a study published in the journal Ocean & Coastal Management found that “nature-based solutions” have also become popular in China. The restoration and conservation of freshwater swamps, mangroves and wetlands along coastlines and river mouths are being used to provide a buffer for tidal and storm surges.
They include the Chongming Island wetland in Shanghai (Yangtze delta) and the Futian and Mai Po wetlands in Shenzhen Bay (Pearl River delta).
Another concept proposed in the planning document is to “accelerate smart development” by using the internet, data and technology to monitor and prevent floods.
The capital Beijing has incorporated data from high-definition cameras, as well as telescopes, radar maps and satellite cloud images to provide real-time hazard updates, which has improved emergency response times.
Ningbo, a port city on China’s east coast, has worked with mobile companies to analyse big data and disseminate information.
The Ministry of Emergency Management said these measures have reduced the number of deaths and missing people as a result of natural disasters by 54% over 2018-22, compared to 2013-17. The death toll continued to fall in 2023 but the number of destroyed buildings and direct economic losses rose by 97% and 13%, respectively, compared with 2018-22 levels.
In 2015, the sponge city programme (SCP) concept was written into a policy document of the Ministry of Housing and Urban-Rural Development. It was promoted across the country and 30 major cities, such as Wuhan (home to 11 million people) and Zhengzhou (home to 10 million people), were chosen to be the pilot cities.
Those sponge cities are designed to collect, purify and re-use at least 70% of the floodwaters through “green-blue facilities”, such as green roofs, permeable pavements and stormwater parks, in urban areas. The overall system was meant to resolve the issues of urban heating, freshwater scarcity and flooding all at once.
China has improved its recovery process too. In Ningbo, for example, flood victims were able to access financial compensation within an hour, using an improved online documentation process during Typhoon In-Fa in 2021.
How effective are these measures?
Chan tells Carbon Brief that China has “done very well in terms of preparation, response and recovery for flood and drought hazards” – the two most destructive types of natural disasters.
“As a global south country,” he says, referring to China as a developing country, “China has done quite well with the SCP [sponge cities programme] and the ecologically enhanced solutions for addressing climate change”.
However, Wing argues that nature-based solutions, such as SCP, can “get saturated quickly” and so “there’s a risk of their role being overstated”. He continues:
“These types of interventions are most effective for rainfall events which occur relatively regularly at low intensities. They will be quickly overwhelmed during the very intense, rare rainfall events (whose probabilities are changing rapidly in a warming world) that cause the most damage and suffering.”
In 2021, a “historically rare” rain and flood, that affected more than 14 million people and killed 398 in Zhengzhou, a showcase sponge city, highlighted the limitations of the SCP in the face of climate change.
SCP is designed to only withstand one-in-30-year rain events, says the Nature study. On top of that, it can create a false sense of security, which encourages more people to move to high-risk areas, leading to an increase in population and assets in exposed areas that require ever-increasing protection in a cycle referred to as a “levee effect”, says Chan.
The levee effect refers to the paradox whereby the construction of a flood-defence levee leads to a lowered perception of flood risks and a greater likelihood of property owners investing in their property, increasing the potential damages should the levee breach.
The effect, according to the Nature paper, is a key challenge in the densely populated Yellow River delta and Pearl River areas, which both face high risks of flooding.
Smiley says:
“Risk is realised when social vulnerabilities intersect with hazards. Vulnerabilities are social. Flood impacts are greater when social vulnerabilities are greater…Social vulnerabilities are uneven. A household with some wealth and good insurance can recover from a flooding event much faster and more successfully than a household living paycheck-to-paycheck.”
The Chinese government has allocated more than one trillion yuan ($138bn) – via a special government bond – to support the vulnerable citizens and reconstruction of areas hit by natural disasters in March this year. More than half of the funds are used for “the construction of water conservancy projects like flood control,” reported state media outlet the Global Times.
But the delivery of financial support has been questioned in the past. When Typhoon Doksuri hit China in 2023, only $2bn out of roughly $25bn in aggregate losses were underwritten, according to global reinsurer Munich Re.
In addition, the construction of those sponge cities has already cost China 1.5-1.8bn yuan ($210-250m) between 2015 and 2018. And maintenance will make this bill even larger.
The authors of the Nature paper suggest that the government should work on integrating fragmented “grey infrastructure” – built structures such as drains, pipework and pumping stations – into existing green-blue facilities, but should not rely on engineered infrastructure alone.
Dr Lele Shu, a researcher at the northwest institute of eco-environment and resources, Chinese Academy of Sciences, tells the Intellectual magazine that “the [impact of] heavy rain at the current rate cannot be mitigated through traditional engineered approaches alone”.
“Everytime there is heavy rain, the damage it causes will make headlines primarily because there are too many people living in the city,” adds Shu.
The lack of coordination between regional governments and municipalities in flood prone areas also often led to fragmented approaches to disaster management.
In the case of the Yangtze and Pearl deltas, there is a lack of delta-wide plans that “systematically zone land and prioritise investments within one unified hydrological system”, the Nature study adds.
Dr Zheng Yan, a researcher at the Research Institute of Eco-civilisation, China Academy of Social Sciences, noted in the aftermath of the 2023 Beijing flood that government bodies often look after their own jurisdiction and aim only to move the problem and divert the floods quickly, which piled pressure on cities in downstream areas.
Smiley says:
“Floodwaters don’t care about human-created boundaries by municipality, district or province. Effective urban design in one locality may lessen flood risk there, but indirectly increase risk elsewhere. Thinking collectively while centering justice means providing spatially extensive and locally attuned solutions that help all recover effectively instead of exacerbating inequalities.”
What can China learn from other cities?
As flooding is a challenge faced by cities across the world, there is a plethora of ideas and technologies that China can draw on.
The Nature paper suggests that the Yangtze and Pearl deltas, for example, could learn from the Ganges-Brahmaputra-Meghna delta and the Mekong delta to “improve their responses to regional challenges such as subsidence and erosion, by using and aligning with the underlying dynamics of the deltas that are rapidly changing in response to climate change and anthropogenic activities”.
Building a resilient society that is “proactive and forward-looking, with adequate capabilities to limit detrimental flooding impacts and timely return to the pre-disaster state” is also advocated by the paper.
Rotterdam, a Dutch delta city of 600,000 people that is surrounded by water on four sides, has built water storage facilities, such as an underground parking garage with a basin the size of four Olympic swimming pools. It has also installed green roofs and facades to absorb rainwater.
Japan has built an intricate network of concrete tunnels and vaults about 14 storeys beneath the Saitama prefecture in the outskirts of Tokyo, Japan’s capital city, that can hold more than 1,000 Olympic pools of rainwater.
Both cities’ underground flood diversion facilities are often used as a prime example of a viable flood defence system for urban cities on the frontline of climate change.
Hong Kong has a similar underground stormwater storage system beneath the sport pitches of the Happy Valley Racecourse, designed to withstand once-in-50-years flood events.
However, Chan says it is difficult to compare flood mitigation measures as each city is very different in terms of geography, demographic, densities and topography.
He tells Carbon Brief:
“But in my opinion, China’s megacities should think about using underground spaces to store the sudden extreme discharge from super intensive rainstorms…Tokyo and Rotterdam are quite wise (in that regard) for using their underground spaces.”
The post Q&A: How China is adapting to increasingly frequent flooding appeared first on Carbon Brief.
Q&A: How China is adapting to increasingly frequent flooding
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.
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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
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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
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Guest post: France’s June heatwave caused more than 2,700 heat-related deaths
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