English schools could exceed an “overheating” threshold of 26C for one-third of the academic year if global warming reaches 2C above pre-industrial temperatures, a new study finds.
The study, published in Climate Risk Management, assesses the risk of overheating in around 20,000 schools across England, using data on the schools’ location, the type of building and the climate.
The authors identify the indoor temperature of 26C as the upper “comfortable” limit in classrooms. While the average school would be expected to surpass this limit for more than one-third of the academic year under 2C of warming, it rises to half of the year for 4C of warming.
The authors also investigate a 35C threshold, above which “important health impacts” are seen. They find that, currently, schools only exceed this temperature threshold once every year, on average.
However, under 4C warming, the average school is expected to exceed this threshold around nine times per year, accounting for 5% of the academic year.
Newer schools are more likely to overheat than their older counterparts, the authors say, because they typically have better insulation and lower ceilings. They add that schools in the south and east of England, as well as London, are at greatest risk of overheating.
The study shows the need for adaptation measures such as improved ventilation, a scientist not involved in the study tells Carbon Brief. She adds that “school buildings need to be designed today with tomorrow’s climate in mind”.
Overheating schools
Over the past month, millions of children in the Philippines, Bangladesh and India stayed home as a record-breaking heatwave forced schools across southern Asia to shut.
However, schools in more temperate climates can also be affected by the heat. In July 2022, the UK experienced a record-breaking heatwave that saw temperatures exceed 40C for the first time on record. During this period, the UK put out its first red heat alert and many schools finished early or closed their doors entirely for the safety of their staff and students.
Extreme heat can be deadly. During a heatwave, the number of “heat-related deaths” – where exposure to heat either causes or significantly contributes to a death – tends to increase.
Children are particularly vulnerable to high temperatures. When it is hot, the human body produces sweat to cool itself down. However, children do not sweat as much as adults and are therefore less able to regulate their body temperature.
Even when temperatures do not reach headline-grabbing highs, any increase above the “optimal” temperature can be harmful. A recent World Bank report estimates that in “middle and high-income settings”, the ideal classroom temperature lies between 19.5C and 23.3C. The report says:
“In those settings, any temperature above 24C can compromise reaction time, processing speed and accuracy through changes in heart rate and respiratory rates…
“Across five experimental studies, high temperature produced declines in student performance ranging from 2 to 12% for each 1C increase in classroom temperature.”
Furthermore, when teachers work in classrooms that are too hot, they can become fatigued or lose concentration, making them more likely to put themselves and the children in their care at risk.
UK guidance suggests a minimum working temperature of 16C, if employees are not carrying out physical work. However, there are no legal maximum working temperatures for schools in the UK.
“Our children spend 30% of their lives in schools,” says Prof Lucelia Rodrigues – chair of sustainable and resilient cities at the University of Nottingham. Rodrigues, who was not involved in the study, tells Carbon Brief that it is “imperative that we provide them with comfortable, healthy environments to thrive and achieve their best”.
Newer buildings
The new study assesses how often English schools overheat, which schools are most at risk and how climate change could exacerbate the problem. The study authors define two temperature thresholds:
- 26C: The “upper limit of comfortable operative temperature in schools”.
- 35C: The temperature at which “important health impacts” are seen.
The authors use the open-access CLIMADA platform to simulate the risk of English schools overheating, combining information on hazard, exposure and vulnerability.
The authors use climate data from the UK Climate Projections 2018 (UKCP18) to determine annual variations in temperature across England over 1998-2017. They then model those temperatures in worlds with average global temperatures of 2C and 4C above pre-industrial levels. This provides the hazard data.
They then quantify exposure using data on the location of around 20,000 primary and secondary state schools in England. And vulnerability is assessed using “physics-based building models” to quantify the link between outdoor and indoor temperature for different types of buildings.
The plot below shows an example of the relationship between outdoor daily average temperature (blue) and indoors daily maximum temperature (red) in two different schools. The dashed and dotted lines indicate the 26C and 35C temperature thresholds, respectively.
The authors find that schools built before 1918 are generally most able to keep cool, while those built after 1967 overheat the most easily.
Dr Laura Dawkins – an “expert scientist” in climate risk and resilience at the UK Met Office, and lead author of the study – tells Carbon Brief that this is due to “differences in typical floor-to-ceiling heights”. Newer schools are typically built with lower ceilings, which cause the room to heat up more quickly, she explains.
Rodrigues adds that newer schools are built to “more stringent building regulations designed to reduce heating energy demand”, making them more airtight and well-insulated. Citing her 2010 study, she continues:
“In classrooms within schools built post-2010, overheating occurred for more than 40% of school hours, whilst in older schools with leakier and non-insulated envelopes overheating was rarely reported.”
Rodrigues says that ventilation is key, noting that it not only prevents buildings from overheating, but can also “improve air quality, which will have a significant impact on productivity” in pupils.
Mapping heat
The study’s findings include a series of maps to show where the most at-risk schools are located.
The maps below show the expected total number of days in an academic year that each school will cross the 26C (left) and 35C (right) temperature thresholds. The top row uses the climate of 1998-2017, the middle row a 2C-warmer world and the bottom row a 4C-warmer world. Darker red indicates more overheating days.
The authors assume 195 days in a school year, to account for weekends and holidays. The analysis does not include August – the hottest part of the year – because schools are typically closed for the summer holidays during this time.
The authors find that schools in south and east of England, as well as London, are at greatest risk of overheating. They add that this is largely due to the urban heat island effect – in which a combination of factors, such as buildings, reduced vegetation and high domestic energy use, cause urban areas to become hotter than more rural regions.
By combining the data from all 20,000 schools, the authors determine how many days the average school is expected to cross the 26C and 35C warming thresholds under different global warming levels. The authors also calculate values for “at-risk” schools – which rank in the highest 10% on their risk metric.
These results are shown in the table below.
| 26C threshold, average school | 26C threshold, at-risk school | 35C threshold, average school | 35C threshold, at-risk school | |
|---|---|---|---|---|
| Recent climate | 59 | 59 | 1 | 1 |
| 2C warming | 71 | 75 | 3 | 5 |
| 4C warming | 89 | 92 | 9 | 13 |
Number days during the academic year that “average” and “at-risk” schools are expected to cross the 26C and 35C warming thresholds under different global warming levels. Adapted from Dawkins et al (2024).
The average school currently exceeds the 26C threshold for 59 days – accounting for around one-third of the academic year – according to the study. However, the authors warn that this could rise to 71 and 89 days under the 2C and 4C scenarios, respectively.
Meanwhile, England’s most at-risk schools currently face one day per year of indoor temperatures above 35C. This could rise to five days per year under a 2C warming scenario, and 13 under a 4C scenario.
This study is “a first attempt at applying the novel spatial risk assessment framework to this real world problem”, according to Dr Dan Bernie climate resilience science manager and health science lead at the UK Met Office and an author on the study.
Bernie tells Carbon Brief that he is currently working on “generating more robust results using individual school building models and higher resolution climate projections”.
Prof David Bresch is a professor at the department of environmental systems science at ETH Zurich and is the founder and senior scientific advisor at CLIMADA. He tells Carbon Brief that the authors have used the platform well, providing a good “prototype” for this type of study.
The biggest “challenge” in the study is the team’s use of fixed temperature thresholds, he says. However, he calls the paper an “important contribution” to the literature, and says that it will allow schools and governments to start thinking about adaptation measures.
Bresch emphasises the importance of adaptation. He tells Carbon Brief that it is crucial to “take a forward looking view of risk”, adding that it comes with the win-win situation of limiting impacts and likely coming with a lower price tag than waiting for major impacts to hit.
Government plans
Every five years, the UK government publishes its Climate Change Risk Assessment (CCRA), which assesses the “current and future risks to and opportunities for the UK from climate change”.
The National Adaptation Programme (NAP) is published shortly afterwards, allowing administrations such as the Department of Education (DfE) to outline how they are planning to adapt to climate change.
In July 2023, the UK government published its third National Adaptation Programme (NAP3). In this report, the DfE recognised the “significant threat” of rising overheating in schools, and highlighted the need for further research to better understand this risk.
The new study was carried out partly in response to this call for research and has experts from both the UK Met Office and DfE in its author list. Bernie tells Carbon Brief that this study was a collaboration between “climate science, data science, building performance models and stakeholder insights”.
The DfE tells Carbon Brief that it has already allocated £138m to make education buildings more sustainable or more resilient to the impacts of climate change. The UK government’s “strategy for the education and children’s services systems” adds:
“All new school buildings delivered by DfE (not already contracted) will be net-zero in operation. They will be designed for a 2C rise in average global temperatures and future-proofed for a 4C rise, to adapt to the risks of climate change, including increased flooding and higher indoor temperatures.”
However, Rodrigues tells Carbon Brief that “there is still no requirement to design for future climate conditions, even though schools typically have at least a 50-year lifespan, with many occupied continuously for over 100 years”. She adds that “school buildings need to be designed today with tomorrow’s climate in mind”.
The DfE tells Carbon Brief that they are working with partners including the Met Office on the next iteration of this research and will provide more information about it later this year.
The post English schools face ‘overheating’ for one-third of year under 2C warming appeared first on Carbon Brief.
English schools face ‘overheating’ for one-third of year under 2C warming
Scientists have vowed to keep working on the next flagship set of reports for the Intergovernmental Panel on Climate Change (IPCC), after a political row over the timeline for their release saw its latest session suspended on Friday evening without agreement.
During the weekend, government officials and scientists alike expressed disappointment over the inability to reach a compromise before some delegates from developing countries and small island states had to leave the week-long meeting in Ethiopia to catch flights home.
The disagreement – which has persisted since early 2024 – turns on whether the three key parts of the AR7 assessment should all be published before the conclusion of the UN’s next Global Stocktake of global climate action, which is due to be completed in late 2028.
The IPCC issued a statement after the close of the session, saying that “key agenda items” – the timelines for the three AR7 reports, as well as the IPCC budget – remain open and under discussion. It said the IPCC’s plenary session and its deliberations on the pending agenda “will resume at the earliest opportunity”, giving no further details of when.
IPCC Chair Jim Skea told delegates in closing remarks that recent months had been some of the most turbulent for the climate science panel and that, if there were stronger words than “profound disappointment” he would use them, according to a summary published by the Earth Negotiators Bulletin (ENB). IPCC discussions happen behind closed doors.
IPCC scientists remained committed
In an open letter, issued on Monday, a group of nearly 120 scientists – from a total of 664 AR7 authors – said they “stand committed to continue working to deliver the AR7 reports in a manner that is rigorous, timely and inclusive, in line with our mandate to be policy-relevant”.
“An assessment that arrives after the decisions it is meant to inform cannot serve its purpose,” they emphasised. “The second Global Stocktake in 2028 is such a decision point, and the world should not have to face it without the IPCCʼs latest assessment.”
Europe, small islands and the least developed countries, plus many Latin American and developed nations, want the IPCC to meet this deadline, arguing that the findings from the UN climate science body are irreplaceable in the UN climate policy-making process.
However, around a dozen developing countries plus Russia have argued that the reports should come later in order to allow for greater research input from the Global South – something that, in their view, would make the findings fairer. They also claim that a shorter timeline would put excessive pressure on experts.
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Who shapes climate science? The equity question facing the IPCC
Early completion of the next global climate science assessment reports risks excluding research from the Global South, which is key to ensuring the findings are fair -
Governments that support climate science must stand firm against naysayers
The IPCC is meeting to decide the timing of its next major report, as some countries try to delay it and weaken the case for faster emissions cuts
The most vocal of this group at last week’s meeting were India and Saudi Arabia, according to the ENB summary and a developed country diplomat. Critics see this push for a longer timeline as an excuse to deprive government decision-makers of the latest science and ease pressure on emerging economies to raise their ambition, particularly on cutting emissions.
Commenting on last week’s meeting, France’s ambassador for climate negotiations Benoît Faraco said a broad coalition of developed and developing countries from all five continents, “united in their support for science and the timeline proposed by scientists”, had withstood pressure “from a few countries” seeking to slow down the process of adopting the IPCC reports.
He added that France would not back down and would “continue to fight tirelessly for science, protect the integrity of information, and convince our partners that without the best available scientific data, we will be less effective in tackling climate change and protecting our populations”.
Inclusivity proposal stalled
In a bid to unlock a solution for the AR7 timeline, countries discussed ways to improve the inclusivity of the IPCC’s work. One option put on the table was for the IPCC to expand its funding for delegates from developing countries to attend some or all of its sessions from one to two participants, according to the ENB summary and a delegate speaking to Climate Home News.
That would increase the costs for the IPCC to complete AR7 by up to a quarter, according to an assessment shared by the secretariat. The panel’s budget is under severe strain and its officials have warned that, without additional voluntary contributions, it risks running out of money before it can deliver on this assessment cycle.
Climate Home News understands that some of the IPCC’s traditional donors – which mainly include European countries, Japan and Australia – indicated a willingness to support funding for an additional developing country participant. But without an agreement over the budget or the timeline for the reports, that option was ultimately not adopted.
‘Disappointed and worried’
The three reports are managed by working groups that collate and draw overall findings from the latest scientific studies and data on the physical effects of global warming around the world, how to adapt to it, and pathways for cutting planet-heating emissions in order to meet the temperature goals of the Paris Agreement.
Winston Chow, an urban climate professor at Singapore Management University who co-chairs Working Group II on adaptation, wrote in a LinkedIn post that he was “disappointed and worried” for the IPCC authors who have worked “extraordinarily hard” to assess the relevant climate science over the past two years.
He said he shared their concern that “the rigour, time and goodwill they’ve invested are now being put at risk by the Panel’s stalemate”.
As science comes under attack at UN talks, climate movement splits over how to respond
For Working Group II, a meeting for 250 experts writing that report is scheduled for January 2027, followed by the approval of a special report on cities and climate change in Singapore next March.
But because the IPCC’s budget has not been confirmed due to uncertainty about the AR7 schedule, travel support for those researchers is at risk, wrote Chow. “If they cannot participate, our assessments will lose vital expertise, perspectives and scientific breadth, and the collective effort of our authors will be undermined,” he warned.
Scientific work continues
Despite the political holdups, he – together with French climate scientist Robert Vautard, co-chair of Working Group 1 – agreed with IPCC head Skea who told the IPCC’s closing session on Friday: “The engine room of the IPCC is working, and it’s healthy.”
Vautard commented in a separate post on LinkedIn after it ended: “The boat is at full steam.” Working groups I and II are due to start revising the first drafts of their reports, while Working Group III on reducing emissions is finalising its first draft which will be out soon, he wrote.
“The most exciting two years of the cycle are ahead, for the authors. The momentum in the engine room is here and now. Trust the engine room!” he added.
The IPCC and some scientists report that progress has been made towards achieving an equitable balance of authors from the Global North and the Global South.
The group of researchers who signed the open letter on Monday noted that “inclusivity is at the heart of how we work”, with author teams bringing together experts from developed and developing countries with diverse backgrounds and at different stages of their careers.
Plea to overcome political differences
The signatories include several scientists from some of the countries opposed to the alignment of all IPCC reports with the Global Stocktake.
“We are committed to an assessment in which the knowledge, experience and priorities of every region are fully reflected, a commitment we share with the leadership of the IPCC.
Equity is built into how our assessment is being drafted,” they added.
They appealed to governments that make up the IPCC “to overcome their political differences and work together as we do as a global scientific community, so that we can deliver the IPCC reports the world needs to hear”.
In a statement published on Monday, IPCC chair Skea said reaching consensus on the schedule for the reports is “vital”. He added that the assessments provide authoritative scientific evidence to inform national climate policies, strengthen adaptation and resilience and support access to climate finance, as well as helping communicate the scale of the climate crisis and the urgency of efforts to tackle it.
The post IPCC scientists vow to press on with climate reports despite political deadlock appeared first on Climate Home News.
IPCC scientists vow to press on with climate reports despite political deadlock
An Lambrechts is a biodiversity politics expert at Greenpeace International with extensive experience in biodiversity-related multilateral negotiations. She is the head of the Greenpeace delegation at the Convention on Biological Diversity (CBD) COP17 happening in Yerevan, Armenia.
In 2022, COP15 delivered the landmark Kunming-Montreal Global Biodiversity Framework to halt and reverse biodiversity loss by 2030. With COP17 starting in Yerevan, we are now halfway to the deadline, and according to the first Global Review of progress, countries are not on track to meet the biodiversity targets, and implementation must accelerate fast.
One of the main findings of the Global Review is that funding falls far short of the scale needed to halt and reverse nature loss. But the crisis facing the world’s biodiversity is not an absolute scarcity of capital – it is a profound public policy distortion.
The global economy currently spends roughly $30 destroying nature for every single dollar invested in its protection. According to a report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, a staggering $2.4 trillion is spent in public subsidies for fossil fuels, agriculture and water use, while global investment in biodiversity conservation and restoration stands at a mere $220 billion.
Countries urged to ramp up “insufficient” nature policies at COP17
Yet, discussions about how to close the biodiversity finance gap continue to claim that salvation lies in mobilising private capital, scaling offsets and “derisking” investments in nature. This is a fundamental misunderstanding of both the nature of ecological stewardship and of the global financial architecture.
Biodiversity conservation is not a speculative investment portfolio – it is the foundation of human survival. The health of our planet is a non-monetisable, non-excludable public good. Expecting profit-seeking private capital to protect nature perpetuates the structural drivers of ecosystem destruction in the first place.
But if private market mechanisms cannot save biodiversity, where will the necessary public resources come from?
Money going to the wrong places
The answer lies in recovering the vast public wealth currently drained by cross-border tax abuse, financial secrecy and corporate impunity. Finance and environment ministers meeting in Yerevan must give a strong political signal that, to avert ecological breakdown, countries need to take swift action to reform global tax rules, eliminate harmful public subsidies and cancel unsustainable sovereign debts for the public revenues to end up where they belong.
Extractive sectors such as industrial agriculture, fishing, timber and mining continue business-as-usual, often heavily subsidised by public treasuries, while voluntary carbon and biodiversity offset markets pose a serious risk to nature conservation. Offset schemes have delivered only a negligible fraction of the funding needed to preserve ecosystems, allowing industries to continue with their destructive business-as-usual practices.