The degradation of trees at the edges of tropical forests is more widespread than previously thought, according to new research.
The study, published in Nature, explains that trees near deforested or degraded areas of the forest are more vulnerable to drought, as well as to human activity such as logging. These “edge effects” are measurable up to 1.5km into the forest, the authors find.
This is an “amazing result”, a study author tells Carbon Brief, because previous studies detected these effects only within the first 120 metres of the forest edge. The new figure indicates that 18% of the remaining tropical moist forests are impacted by edge effects – an area more than 200% larger than previously estimated.
Experts not involved in the study tell Carbon Brief that quantifying tropical forest degradation is “frustratingly elusive”. And while some praise the methods used in the paper, others advise caution when interpreting the conclusions.
Two Brazilian scientists also tell Carbon Brief that the study overlooks important work from institutions in the global south who are also working on this problem. They advise that scientists from local groups should be invited to contribute to research in this area.
Forest height
Tropical forests account for around 45% of forest cover globally. These forests are well-known for their high biodiversity and the crucial ecosystem services that they provide. They also hold around one-quarter of all land-based carbon.
The new study assesses how deforestation and degradation affect “moist tropical forests” – tropical forests in the equatorial belt with a fairly consistent annual temperature and high levels of rainfall. Tropical dry forests and deciduous forests are not included in the analysis.
Research shows that around 17% of tropical moist forests disappeared over 1990-2021, largely due to human activity such as logging and fires. Of the 1,071m hectares that remained globally in 2019, around 10% were degraded, the new study says. This means that they suffered human-induced “disturbances” that led to a partial loss of their tree cover or function.
Furthermore, trees at the edges of tropical forests have higher mortality rates than trees in the centre, because they are more exposed to disturbances such as fire and drought. When intact forest landscapes become fragmented – for example, due to logging, fire, drought or the construction of roads into the forest – these “edge effects” can lead to further forest degradation.
The authors use data collected by the Global Ecosystem Dynamics Investigation (GEDI) instrument on the International Space Station to assess the forest structure – such as canopy height and aboveground biomass – over the past four years.
To measure canopy height, the authors calculate the “RH98” value – the height of the top of the canopy or the nearest tallest vegetation in the area. This is an important measure of forest health and maturity. Aboveground biomass measures the aboveground woody biomass per unit area and is also a good measure of forest health.
They combine this with data from the Tropical Moist Forest dataset, which uses Landsat satellite imagery to show how tropical moist forests have changed over 1990-2022.
The plot below shows the canopy height for different types of moist tropical forests. The rows show intact forests at least 3km from a forest edge (top row), degraded forests (second row), the edges of forests (third row) and forest regrowth (bottom row), as shown in the maps below.
Darker blues indicate taller forest canopies. The map shows where the forests are located, and the bar charts on the right hand side show the overall distribution of different tree heights.
The tallest intact moist tropical forests are found in south-east Asia, where the average canopy height is 34m, the study finds. West and central Africa and Central and South America have average forest heights of 29m. This is because intact tropical forests in Asia, which are typically dominated by “hardwood wind-dispersed species”, are typically taller, the authors say.
The map also shows that degraded forests, forest edges and areas of forest growth have a greater proportion of shorter trees on average.
The forest edge
The study investigates two different types of forest edge effects, exploring how areas of deforested and degraded land impact nearby trees.
Dr Lilian Blanc is an author on the study and researcher at the French Agricultural Research Centre for International Development. He tells Carbon Brief that the effect of nearby degraded land “was not considered in previous studies”.
The graphs below show how areas of deforested land affect tree canopy height. The charts at the top show the average distribution of canopy heights of undisturbed forests in the Americas, Africa and Asia. The line colours indicate the distance of those trees from the forest edge, with yellow indicating a short distance and blue indicating a large distance.
The bottom map shows how far into the forest edge effects are present, by measuring the distance from the forest edge at which the height of the forest reaches 95% of the height of the intact, undisturbed forest.
The authors find the greatest edge effects from deforestation along the “forestation fronts of the Amazon”, in Borneo and Sumatra coasts marked by high fragmentation levels, and on the borders of the Congo basin.
They also record a decrease in canopy height up to 350, 400 and 1,500 metres from the deforested edge in the Americas, Africa and Asia, respectively.
The authors find that within 120 metres of trees that have been degraded due to logging and burning, the average canopy height in undisturbed forests is 15% and 22% lower, respectively.
The authors also investigate how quickly the forest can recover from logging and fires, concluding that while there is “fast regrowth of pioneer and understory species”, there is “no significant recovery in canopy height in the 30 years following the creation of a forest edge”.
Forest degradation can also increase the likelihood of deforestation, the authors say. They warn that forest height and distance to the edge of the forest are “strong predictors of deforestation”, as forest fragmentation makes the interior of the forest more accessible to loggers.
It adds that there has been selective logging 500 metres from the forest edge in Africa and the Americas, and even deeper in Asia.
Agriculture and road expansion trigger a 20-30% reduction in canopy height and biomass at the forest edge, with “persistent effects” measurable up to 1.5km inside the forest, the authors find. Blanc tells Carbon Brief that this is “an amazing result” as previous studies only looked for edge effects up to 120 metres from the forest edge.
The authors also calculated the edge effect using total above ground woody biomass, instead of canopy height. Using this metric, the authors conclude that the total area of forest with this edge effect is 18% of total global forest area in 2022 – an area more than 200% larger than previously estimated.
Prof Simon Lewis – a professor of global change science at University College London’s department of geography – tells Carbon Brief that this is a “striking new result”.
It implies that “the negative impacts on remaining forest from the creation of forest edges are much more extensive than has been commonly documented”. It also means that “forest protection of large blocks of forest is going to be more important than we previously thought”, he says.
Overall, the study is “an important step forward in monitoring forest disturbance, which is a very tough problem”, Lewis says. However, he adds that “care is needed” when looking at some of the observational data, saying that he “trust[s] the broad patterns of biomass loss following logging, edge creation and fires, but not the specific biomass loss values from these disturbances”.
Dr Peter Potapov – a researcher in the department of geographical sciences at the University of Maryland, whose work was cited extensively in the new study – says “the conclusion that edge effects are degrading 18% of the remaining humid tropical forest is an overstatement”.
He says that forest degradation depends on other factors, such as land-use regulations, and argues that “the assumption that all forests 1.5km away from the edges are degraded may undermine ongoing conservation efforts.
Expert response
These comments reflect the mixed response that the new study has received.
Prof Matthew Hansen – a remote sensing scientist at the University of Maryland’s department of geography – tells Carbon Brief that forest degradation is “a frustratingly elusive dynamic to quantify”. However, he praises the study for being “very clear and ambitious”.
Potapov, who has published research with Hansen, tells Carbon Brief that the results broadly confirm existing findings, but warns that there are some “major limitations” with the study.
For example, he says the method does not include a “matching technique” to separate the effect of human management on tree height from the natural factors such as elevation, soil quality and floods. He also warns that the observations “failed to correctly map anthropogenic disturbances in humid tropical forests”, adding:
“The authors greatly underestimate selective logging in Gabon, while the natural non-fire disturbances like river meandering and windfalls in South America were probably treated as human-caused degradation.”
Dr Flávia de Souza Mendes, a programme manager in forest and land use at satellite imagery firm Planet Labs, says the study is “well written”. However, she laments that “there are several local groups from the global south that have been studying this topic and are not part of this study”. She suggests that scientists carrying out similar studies should “invite more local researchers to take part”.
She also tells Carbon Brief that this paper “did not take into account studies carried out by local researchers on the relationship between degradation and deforestation”.
For example, she highlights a report by Brazilian researchers which finds that, in some regions of the Amazon, 86% of degraded areas were not subsequently cleared in the following decades. This is not in line with the findings of the new study, where degradation “has a crucial role in predicting future deforestation”, she says.
Prof Celso Silva-Junior – a research scientist in amazon ecology and remote sensing at Brazil’s Universidade Federal do Maranhão – tells Carbon Brief that the study “reproduces the findings of our research group, which has been investigating large-scale forest edge effects, using remote sensing technologies, since 2016”.
He says that the paper’s findings concerning biomass loss beyond 120 metres from the forest edge are “critical”. However, he emphasises the importance of the “local knowledge of tropical scientists” who are “deeply involved in the establishment of the conceptual framework for treating this relevant problem”.
The post Tropical forest degradation due to ‘edge effects’ is 200% higher than thought appeared first on Carbon Brief.
Tropical forest degradation due to ‘edge effects’ is 200% higher than thought
Greenhouse Gases
Cropped 13 August 2025: Fossil-fuelled bird decline; ‘Deadly’ wildfires; Empty nature fund
We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.
This is an online version of Carbon Brief’s fortnightly Cropped email newsletter. Subscribe for free here.
Key developments
‘Deadly’ wildfires
WINE BRAKE: France experienced its “largest wildfire in decades”, which scorched more than 16,000 hectares in the country’s southern Aude region, the Associated Press said. “Gusting winds” fanned the flames, Reuters reported, but local winemakers and mayors also “blam[ed] the loss of vineyards”, which can act as a “natural, moisture-filled brake against wildfires”, for the fire’s rapid spread. It added that thousands of hectares of vineyards were removed in Aude over the past year. Meanwhile, thousands of people were evacuated from “deadly” wildfires in Spain, the Guardian said, with blazes ongoing in other parts of Europe.
MAJOR FIRES: Canada is experiencing its second-worst wildfire season on record, CBC News reported. More than 7.3m hectares burned in 2025, “more than double the 10-year average for this time of year”, the broadcaster said. The past three fire seasons were “among the 10 worst on record”, CBC News added. Dr Mike Flannigan from Thompson Rivers University told the Guardian: “This is our new reality…The warmer it gets, the more fires we see.” Elsewhere, the UK is experiencing a record year for wildfires, with more than 40,000 hectares of land burned so far in 2025, according to Carbon Brief.
-
Sign up to Carbon Brief’s free “Cropped” email newsletter. A fortnightly digest of food, land and nature news and views. Sent to your inbox every other Wednesday.
WESTERN US: The US state of Colorado has recorded one of its largest wildfires in history in recent days, the Guardian said. The fire “charred” more than 43,300 hectares of land and led to the temporary evacuation of 179 inmates from a prison, the newspaper said. In California, a fire broke out “during a heatwave” and burned more than 2,000 hectares before it was contained, the Los Angeles Times reported. BBC News noted: “Wildfires have become more frequent in California, with experts citing climate change as a key factor. Hotter, drier conditions have made fire seasons longer and more destructive.”
FIRE FUNDING: “Worsening fires” in the Brazilian Amazon threaten new rainforest funding proposals due to be announced at the COP30 climate summit later this year, experts told Climate Home News. The new initiatives include the Tropical Forests Forever Facility, which the outlet said “aims to generate a flow of international investment to pay countries annually in proportion to their preserved tropical forests”. The outlet added: “If fires in the Amazon continue to worsen in the years to come, eligibility for funding could be jeopardised, Brazil’s environment ministry acknowledged.”
Farming impacts
OUT OF ORBIT: US president Donald Trump moved to “shut down” two space missions which monitor carbon dioxide and plant health, the Associated Press reported. Ending these NASA missions would “potentially shu[t] off an important source of data for scientists, policymakers and farmers”, the outlet said. Dr David Crisp, a retired NASA scientist, said the missions can detect the “glow” of plant growth, which the outlet noted “helps monitor drought and predict food shortages that can lead to civil unrest and famine”.
FARM EXTREMES: Elsewhere, Reuters said that some farmers are considering “abandoning” a “drought-hit” agricultural area in Hungary as “climate change cuts crop yields and reduces groundwater levels”. Scientists warned that rising temperatures and low rainfall threaten the region’s “agricultural viability”, the newswire added. Meanwhile, the Premium Times in Nigeria said that some farmers are “harvest[ing] crops prematurely” due to flooding fears. A community in the south-eastern state of Imo “has endured recurrent floods, which wash away crops and incomes alike” over the past decade, the newspaper noted.
SECURITY RISKS: Food supply chains in the UK face “escalating threats from climate impacts and the migration they are triggering”, according to a report covered by Business Green. The outlet said that £3bn worth of UK food imports originated from the 20 countries “with the highest numbers of climate-driven displacements” in 2024, based on analysis from the Energy and Climate Intelligence Unit. The analysis highlighted that “climate impacts on food imports pose a threat to UK food security”. Elsewhere, an opinion piece in Dialogue Earth explored how the “role of gender equity in food security remains critically unaddressed”.
Spotlight
Fossil-fuelled bird decline
This week, Carbon Brief covers a new study tracing the impact of fossil-fuelled climate change on tropical birds.
Over the past few years, biologists have recorded sharp declines in bird numbers across tropical rainforests – even in areas untouched by humans – with the cause remaining a mystery.
A new study published this week in Nature Ecology and Evolution could help to shed light on this alarming phenomenon.
The research combined ecological and climate attribution techniques for the first time to trace the fingerprint of fossil-fuelled climate change on declining bird populations.
It found that an increase in heat extremes driven by climate change has caused tropical bird populations to decline by 25-38% in the period 1950-2020, when compared to a world without warming.
In their paper, the authors noted that birds in the tropics could be living close to their “thermal limits”.
Study lead author Dr Maximilian Kotz, a climate scientist at the Barcelona Supercomputing Center in Spain, explained to Carbon Brief:
“High temperature extremes can induce direct mortality in bird populations due to hyperthermia and dehydration. Even when they don’t [kill birds immediately], there’s evidence that this can then affect body condition which, in turn, affects breeding behaviour and success.”
Conservation implications
The findings have “potential ramifications” for commonly proposed conservation strategies, such as increasing the amount of land in the tropics that is protected for nature, the authors said. In their paper, they continued:
“While we do not disagree that these strategies are necessary for abating tropical habitat loss…our research shows there is now an additional urgent need to investigate strategies that can allow for the persistence of tropical species that are vulnerable to heat extremes.”
In some parts of the world, scientists and conservationists are looking into how to protect wildlife from more intense and frequent climate extremes, Kotz said.
He referenced one project in Australia which is working to protect threatened wildlife following periods of extreme heat, drought and bushfires.
Prof Alex Pigot, a biodiversity scientist at University College London (UCL), who was not involved in the research, said the findings reinforced the need to systematically monitor the impact of extreme weather on wildlife. He told Carbon Brief:
“We urgently need to develop early warning systems to be able to anticipate in advance where and when extreme heatwaves and droughts are likely to impact populations – and also rapidly scale up our monitoring of species and ecosystems so that we can reliably detect these effects.”
There is further coverage of this research on Carbon Brief’s website.
News and views
EMPTY CALI FUND: A major voluntary fund for biodiversity remains empty more than five months after its launch, Carbon Brief revealed. The Cali Fund, agreed at the COP16 biodiversity negotiations last year, was set up for companies who rely on nature’s resources to share some of their earnings with the countries where many of these resources originate. Big pharmaceutical companies did not take up on opportunities to commit to contributing to the fund or be involved in its launch in February 2025, emails released to Carbon Brief showed. Just one US biotechnology firm has pledged to contribute to the fund in the future.
LOSING HOPE: Western Australia’s Ningaloo reef – long considered a “hope spot” among the country’s coral reefs for evading major bleaching events – is facing its “worst-ever coral bleaching”, Australia’s ABC News reported. The ocean around Ningaloo has been “abnormally” warm since December, resulting in “unprecedented” bleaching and mortality, a research scientist told the outlet. According to marine ecologist Dr Damian Thomson, “up to 50% of the examined coral was dead in May”, the Sydney Morning Herald said. Thomson told the newspaper: “You realise your children are probably never going to see Ningaloo the way you saw it.”
‘DEVASTATION BILL’: Brazil’s president, Luiz Inácio Lula da Silva, signed a “contentious” environmental bill into law, but “partially vetoed” some of the widely criticised elements, the Financial Times reported. Critics, who dubbed it the “devastation bill”, said it “risked fuelling deforestation and would harm Brazil’s ecological credentials” just months before hosting the COP30 climate summit. The newspaper said: “The leftist leader struck down or altered 63 of 400 provisions in the legislation, which was designed to speed up and modernise environmental licensing for new business and infrastructure developments.” The vetoes need to be approved by congress, “where Lula lacks a majority”, the newspaper noted.
RAINFOREST DRILLING: The EU has advised the Democratic Republic of the Congo (DRC) against allowing oil drilling in a vast stretch of rainforest and peatland that was jointly designated a “green corridor” earlier this year, Climate Home News reported. In May, the DRC announced that it planned to open the conservation area for drilling, the publication said. A spokesperson for the European Commission told Climate Home News that the bloc “fully acknowledges and respects the DRC’s sovereign right to utilise its diverse resources for economic development”, but that it “highlights the fact that green alternatives have facilitated the protection of certain areas”.
NEW PLAN FOR WETLANDS: During the 15th meeting of the Ramsar Convention on Wetlands, held in Zimbabwe from 23 to 31 July, countries agreed on the adoption of a new 10-year strategic plan for conserving and sustainably using the world’s wetlands. Down to Earth reported that 13 resolutions were adopted, including “enhancing monitoring and reporting, capacity building and mobilisation of resources”. During the talks, Zimbabwe’s environment minister announced plans to restore 250,000 hectares of degraded wetlands by 2030 and Saudi Arabia entered the Convention on Wetlands. Panamá will host the next COP on wetlands in July 2028.
MEAT MADNESS: DeSmog covered the details of a 2021 public relations document that revealed how the meat industry is trying to “make beef seem climate-friendly”. The industry “may have enlisted environmental groups to persuade people to ‘feel better’ about eating beef”, the outlet said, based on this document. The strategy was created by a communications agency, MHP Group, and addressed to the Global Roundtable for Sustainable Beef. One of the key messages of the plan was to communicate the “growing momentum in the beef industry to protect and nurture the Earth’s natural resources”. MHP Group did not respond to a request for comment, according to DeSmog.
Watch, read, listen
MAKING WAVES: A livestream of deep-sea “crustaceans, sponges and sea cucumbers” has “captivated” people in Argentina, the New York Times outlined.
BAFFLING BIRDS: The Times explored the backstory to the tens of thousands of “exotic-looking” parakeets found in parks across Britain.
PLANT-BASED POWER: In the Conversation, Prof Paul Behrens outlined how switching to a plant-based diet could help the UK meet its climate and health targets.
MARINE DISCRIMINATION: Nature spoke to a US-based graduate student who co-founded Minorities in Shark Science about her experiences of racism and sexism in the research field.
New science
- Applying biochar – a type of charcoal – to soils each year over a long period of time can have “sustained benefits for crop yield and greenhouse gas mitigation”, according to a Proceedings of the National Academy of Sciences study.
- New research, published in PLOS Climate, found that nearly one-third of highly migratory fish species in the US waters of the Atlantic Ocean have “high” or “very high” vulnerability to climate change, but the majority of species have “some level of resilience and adaptability”.
- A study in Communications Earth & Environment found a “notable greening trend” in China’s wetlands over 2000-23, with an increasing amount of carbon being stored in the plants growing there.
In the diary
- 18-29 August: Second meeting of the preparatory commission for the Agreement on Marine Biological Diversity of Areas beyond National Jurisdiction | New York
- 24-28 August: World Water Week | Online and Stockholm, Sweden
- 26-29 August: Sixth forum of ministers and environment authorities of Asia Pacific | Nadi, Fiji
Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz. Please send tips and feedback to cropped@carbonbrief.org
The post Cropped 13 August 2025: Fossil-fuelled bird decline; ‘Deadly’ wildfires; Empty nature fund appeared first on Carbon Brief.
Cropped 13 August 2025: Fossil-fuelled bird decline; ‘Deadly’ wildfires; Empty nature fund
CCL submits a formal comment on EPA’s proposed endangerment finding rollback
By Dana Nuccitelli, CCL Research Manager
On July 29, the EPA proposed to rescind its 2009 endangerment finding that forms the basis of all federal climate pollution regulations.
Without the endangerment finding, the EPA may not be allowed or able to regulate greenhouse gas pollution from sources like power plants or vehicle tailpipes, as they have done for years. News coverage has framed this as a “radical transformation” and a “bid to scrap almost all pollution regulations,” so it has appropriately alarmed many folks in the climate and environment space.
At CCL, we focus our efforts on working with Congress to implement durable climate policies, and so we don’t normally take actions on issues like this that relate to federal agencies or the courts. Other organizations focus their efforts on those branches of the government and are better equipped to spearhead this type of moment, and we appreciate those allies.
But in this case, we did see an opportunity for CCL’s voice — and our focus on Congress — to play a role here. We decided to submit a formal comment on this EPA action for two reasons.
First, this decision could have an immense impact by eliminating every federal regulation of climate pollutants in a worst case scenario. Second, this move relates to our work because the EPA is misinterpreting the text and intent of laws passed by Congress. Our representatives have done their jobs by passing legislation over the past many decades that supports and further codifies the EPA’s mandate to regulate climate pollution. That includes the Clean Air Act, and more recently, the Inflation Reduction Act. We at CCL wanted to support our members of Congress by making these points in a formal comment.
There has been a tremendous public response to this action. In just over one week, the EPA already received over 44,000 public comments on its decision, and the public comment period will remain open for another five weeks, until September 15.
To understand more about the details and potential outcomes of the EPA’s actions, read my article on the subject at Yale Climate Connections, our discussion on CCL Community, and CCL’s formal comment, which represents our entire organization. As our comment concludes,
“In its justifications for rescinding the 2009 endangerment finding, the Reconsideration has misinterpreted the text of the Clean Air Act, Congress’ decadeslong support for the EPA’s mandate to regulate greenhouse gas emissions from motor vehicles and other major sources, and the vast body of peer-reviewed climate science research that documents the increasingly dangerous threats that those emissions pose to Americans’ health and welfare. Because the bases of these justifications are fundamentally flawed, CCL urges the EPA to withdraw its ill-conceived Reconsideration of the 2009 endangerment finding. The EPA has both the authority and the responsibility to act. Americans cannot afford a retreat from science, law, and common sense in the face of a rapidly accelerating climate crisis.”
After the EPA responds to the public comment record and finalizes its decision, this issue will ultimately be decided by the Supreme Court several years from now.
In the meantime, CCL will continue to focus our efforts on areas where we can make the biggest difference in preserving a livable climate. Right now, that involves contacting our members of Congress to urge them to fully fund key climate and energy programs and protect critical work at the National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), and Department of Energy. We’ve set an ambitious goal of sending 10,000 messages to our members of Congress, so let’s all do what CCL does best and make our voices heard on this critical issue.
This action by the EPA also reminds us that federal regulations are fragile. They tend to change with each new administration coming into the White House. Legislation passed by Congress – especially when done on a bipartisan basis – is much more durable. That’s why CCL’s work, as one of very few organizations engaging in nonpartisan advocacy for long-lasting climate legislation, is so critical.
That’s especially true right now when we’re seeing the Trump administration slam shut every executive branch door to addressing climate change. We need Congress to step up now more than ever to implement durable solutions like funding key climate and energy programs, negotiating a new bipartisan comprehensive permitting reform bill, implementing healthy forest solutions like the Fix Our Forests Act, and advancing conversations about policies to put a price on carbon pollution. Those are the kinds of effective, durable, bipartisan climate solutions that CCL is uniquely poised to help become law and make a real difference in preserving a livable climate.
For other examples of how CCL is using our grassroots power to help ensure that Congress stays effective on climate in this political landscape, see our full “Holding the Line on Climate” blog series.
The post Holding the line on climate: EPA appeared first on Citizens' Climate Lobby.
Greenhouse Gases
Analysis: England’s most ethnically diverse areas are 15 times more likely to face extreme heat
Neighbourhoods in England that are home to the most minority-ethnic people are 15 times more likely to face extreme heat than the least diverse areas, according to Carbon Brief analysis.
People with the lowest carbon footprints – who therefore contribute less to climate change – are also more likely to live in areas that experience high temperatures.
This is based on Carbon Brief analysis that combines satellite data on heat exposure with data on per-capita emissions, ethnicity and levels of deprivation across England.
Thousands of deaths in the UK have been attributed to heat in recent years and the threat is expected to grow as climate change worsens.
But heat is also felt differently across the country, with certain groups both more exposed and more vulnerable to dangerous temperatures.
Broadly, the analysis shows how those subject to the “urban heat island” effect in English cities, often in low-quality housing and with little access to green space, are more likely to experience extreme heat.
Experts tell Carbon Brief that policymaking should reflect the reality of climate change “amplifying” inequalities across society and provide help to those most in need, such as more heat-resilient social housing.
Heat threat
As greenhouse gas emissions and global temperatures rise, more people in the UK are likely to become ill or even die due to extreme heat.
Heat has killed around 6,000 people in England over the past three years, according to government figures. This is roughly double the number killed over the same period between 2016 and 2018.
Scientists have repeatedly linked extreme heat – and the resulting deaths – to climate change.
In June 2025 alone, more than 260 people died in London due to a heatwave, according to a recent attribution study that linked the event to climate change.
Government advisor the Climate Change Committee (CCC) estimates that the number of heat-related fatalities in the UK each year is set to triple by 2050, without adaptation measures.
Around half of homes in the country are already at risk of overheating and the CCC expects this to reach 90%, if global temperatures rise by 2C above pre-industrial levels.
However, these risks will not fall equally across society, with children, the elderly and disabled people more vulnerable to heat-related illness. There is also evidence that poorer communities and people of colour are more vulnerable to extreme heat.
Such communities also tend to have lower carbon footprints than those that are whiter and wealthier.
This fits with the broader concept of climate justice, which describes how people who are least responsible for climate change often end up bearing the brunt of its effects.
Carbon footprints
To investigate these issues, Carbon Brief combined detailed satellite data on heat exposure across England, provided by 4 Earth Intelligence, with neighbourhood-level carbon footprints compiled by the Centre for Research in Energy Demand Solutions (CREDS).
The CREDS dataset provides estimates of per-person carbon footprints, indicating how much the average person in each neighbourhood is contributing to climate change.
Due to data availability, this analysis focuses exclusively on England, the nation that experiences the most extreme heat in the UK.
Every neighbourhood is scored based on its “heat hazard”, meaning the likelihood that it will experience higher relative temperatures during hot weather, compared to surrounding areas.
The analysis then zooms in on the 10% worst-affected neighbourhoods in England. These neighbourhoods have a heat hazard score of 4 or 5, meaning that they face higher exposure to heat than 90% of areas around the country. (For a full explanation, see Methodology.)
The figure below shows that neighbourhoods with lower carbon footprints are twice as likely to face high heat hazard scores than areas with higher carbon footprints.
Specifically, it shows that 13.4% of neighbourhoods with the lowest carbon footprints are among the English areas most exposed to heat hazards. In contrast, only 7.0% of neighbourhoods with the highest carbon footprint are among the most heat-exposed areas.
Neighbourhoods in England with lower carbon footprints are often in dense, urban areas, where people tend to be less reliant on cars and more likely to live in energy-efficient flats.
Areas with higher carbon footprints are commonly found in rural areas, where travelling by car can be a necessity due to limited public transport.
Also, particularly in south-east England, people in these rural neighbourhoods are often wealthier, meaning they spend more money on flights and other high-emitting luxuries.
Ethnicity and deprivation
Carbon Brief also analysed the heat threat facing deprived neighbourhoods in England and those that are home to more people of colour.
Information about how many people identify as black, Asian and other minority ethnicities in each neighbourhood is based on 2021 census data, via the Office for National Statistics.
As the chart below shows, there is a clear correlation between the number of people of colour living in a neighbourhood and the likelihood of it facing extreme heat during periods of hot weather.
The most ethnically diverse neighbourhoods – where roughly half or more of the population are people of colour – are 15 times more likely to have high heat hazard scores than the least ethnically diverse neighbourhoods, where almost everyone is white.
Among the most diverse areas are parts of Newham in east London, Saltley in Birmingham and Spinney Hills in Leicester, all of which are inner-city areas.
The least diverse neighbourhoods range from coastal parts of Redcar and Cleveland in North Yorkshire to the rural villages of south Somerset. None of England’s hottest 1% of neighbourhoods are in this bracket.
Additionally, Carbon Brief assessed the relationship between levels of poverty and heat risk, based on England’s indices of deprivation dataset. This covers several measures of deprivation, including income, employment and health.
People living in the most deprived English neighbourhoods are more than three times as likely to face high levels of heat hazard as those in the least deprived neighbourhoods, as shown in the figure below.
The correlation between poverty and extreme heat is less extreme than the one between heat exposure and ethnicity.
While many of England’s most deprived areas are in cities, they are also clustered in some rural and coastal areas – such as parts of Cornwall and Lincolnshire – which tend to be cooler.
Urban heat island
The key phenomenon captured by this analysis is the urban heat island effect. This describes how cities – and particularly areas with dense buildings, roads and stretches of concrete that absorb heat – tend to be hotter than the surrounding countryside.
Cities such as London, Manchester and Birmingham have reached temperatures up to 5C hotter than the surrounding areas in recent decades, due to this effect.
The diagram below shows how air flows circulate between rural and urban areas, forming “heat domes” over cities.
Inner-city areas in England are also home to many people facing high levels of deprivation, as well as large black and Asian communities. Many of these communities are therefore exposed to more dangerous temperatures due to the urban heat island effect.
Access to green spaces, even within cities, also influences exposure to the urban heat island effect. Research has shown how people in deprived areas and people of colour – particularly black people – are more likely to live in areas with less access to green spaces.
There is already extensive scientific literature that uses satellite data to demonstrate the urban heat island effect in cities and other locations.
A number of studies have also used this data to show how people of colour and those living in poverty are more exposed to extreme heat. Much of this research has come from the US, where historic housing inequalities have created stark patterns of segregation in many cities.
A project led by environmental policy researcher Dr Angel Hsu of the University of North Carolina-Chapel Hill shows how, globally, “cities are burdening lower-income populations with higher heat exposure”, as she tells Carbon Brief.
Given this, Hsu adds that “it’s not surprising to us to see similar disproportionate exposure patterns among UK neighbourhoods”.
Other researchers tell Carbon Brief that it is important to be wary of satellite data, as it does not precisely capture the air temperatures experienced in these neighbourhoods.
Dr Charles Simpson, who researches the health and economic impacts of climate change at University College London (UCL), notes:
“Satellite-measured surface temperature does not always correlate with the air temperature – what you are measuring includes a lot of road surfaces and rooftops. The air temperature is thought to be more directly relevant to people’s health and their cooling needs.”
Previous research has found that satellite data can therefore overestimate the urban heat island effect compared to data from weather stations.
These stations, however, are not widespread enough to allow comparisons with detailed neighbourhood data. They are particularly lacking in more deprived areas in England, potentially making measurements there less reliable.
Other scientists tell Carbon Brief that, in the absence of a comprehensive ground monitoring network, satellite measurements can serve as a stand-in to estimate heat exposure. Dr Chloe Brimicombe, an extreme-heat researcher based at the University of Graz, explains:
“Although it’s not a good indicator of perceived [temperature], it is a good indicator of what regions are most built up and have the environments that are most vulnerable to heat.”
‘Amplifying’ inequalities
There is a growing body of evidence gathered by activists, scientists and local governments around the UK revealing the unequal burden of climate change.
Dr Charles Ogunbode, an assistant professor of applied psychology at the University of Nottingham who specialises in how people experience climate change, tells Carbon Brief that this kind of data helps to clarify the links between climate change and inequalities:
“We can’t avoid dealing with the issue of social inequalities and climate change is just basically amplifying those things. It’s highlighting them, it’s revealing them. So whatever policies we put in place – be it in the health sector, be it in the climate sector – addressing those inequalities has to be an essential part of whatever those responses are.”
There are many factors influencing how people experience heat that are not captured in Carbon Brief’s analysis.
Previous work by researchers at the University of Manchester and Friends of the Earth has explored this issue, including an analysis of more than 40 indicators that could make neighbourhoods more “socially vulnerable” to heat.
This reveals similar outcomes, with people of colour and those contributing the least to climate change generally more vulnerable to its impacts.
One of the biggest factors that contributes to people’s exposure to heat extremes in the UK is the country’s housing stock, which is “not fit for the future”, according to the CCC.
UK homes have generally not been built for hotter conditions and poorer people are more likely to live in badly adapted housing. Those living in small homes, flats and social housing in England all “suffer significantly more overheating” during heatwaves, according to one study.
Dr Giorgos Petrou, a researcher in building physics modelling at UCL, tells Carbon Brief that it is also vital to consider whether households have the ability to adapt to climate change. “Amongst other factors, their capability will depend on their financial means and whether they own or rent their home,” he says.
Experts tell Carbon Brief that the government should act across its policy agenda to not only address extreme heat, but also support those who are most affected by it. This could involve expanding tree cover and renovating old social housing stock in at-risk communities.
Emma Howard Boyd, a former chair of the Environment Agency who also chaired the London Climate Resilience Review, tells Carbon Brief:
“I do think that with [the Labour] government focusing on house building and retrofit, this is a fantastic opportunity to get this right…For those communities that have had the least impact on the environment and climate change themselves.”
Methodology
This analysis collates several datasets that cover England at a neighbourhood level, with “neighbourhoods” defined as lower-layer super output areas (LSOAs). These are small statistical areas used by the UK government, covering populations of about 1,500-3,000 people. There are 33,755 LSOAs in England.
Data on vulnerability to heat comes from 4 Earth Intelligence (4EI), which analyses land surface temperature to generate “heat hazard” information at a 30m resolution. This detailed information has been converted into LSOAs by 4EI.
Heat hazard scores are calculated by 4EI, based on the likelihood that a given neighbourhood will experience high temperatures during hot weather, relative to the surrounding area.
Each score corresponds to a different percentile of English neighbourhoods. The bar below shows the percentage breakdown across all LSOAs in England.
The two hottest scores – those coloured in red – correspond to the 10% of English neighbourhoods that have higher heat hazard scores than the remaining 90%.
For simplicity, Carbon Brief’s analysis focuses on the red bars above, meaning neighbourhoods in either the top 90th-99th percentile or 99th percentile of heat hazard. (Neighbourhoods in the 90th-99th percentile have higher heat hazard scores than 90% of areas in England. Neighbourhoods in the 99th percentile have higher heat hazard scores than 99% of areas.)
It shows how these two scores are overrepresented in LSOAs that have lower carbon footprints, more diverse communities and higher levels of deprivation.
Carbon-footprint data is from the CREDS “place-based carbon calculator”, which estimates the average per-person carbon footprint for every LSOA in England. It accounts for emissions-producing activities ranging from electricity use to “consumption of goods and services”.
CREDS assigns the grades “A” to “F” (low carbon footprint to high carbon footprint) to neighbourhoods. Carbon Brief has based its carbon-footprint analysis on these grades.
LSOA-level data on black, Asian and other minority-ethnic populations comes from 2021 census data. English LSOAs were broken down into deciles, based on the percentage of the population that identified as non-white ethnicities.
The lowest decile covered the tenth of LSOAs with between 0 and 2% non-white minority-ethnic populations and the highest covered the tenth with more than 51%.
England’s indices of multiple deprivation dataset also includes LSOA-level information. It provides relative measures of deprivation for LSOAs in England, based on income, employment, education, health, crime, living environment and barriers to housing and services. Carbon Brief broke the LSOAs down into deciles based on the total deprivation scores, from the most deprived to the least deprived.
The post Analysis: England’s most ethnically diverse areas are 15 times more likely to face extreme heat appeared first on Carbon Brief.
Analysis: England’s most ethnically diverse areas are 15 times more likely to face extreme heat
-
Climate Change2 years ago
Spanish-language misinformation on renewable energy spreads online, report shows
-
Climate Change Videos2 years ago
The toxic gas flares fuelling Nigeria’s climate change – BBC News
-
Greenhouse Gases1 year 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 Change1 year 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”
-
Carbon Footprint1 year agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits
-
Climate Change2 years ago
Why airlines are perfect targets for anti-greenwashing legal action
-
Climate Change Videos2 years ago
The toxic gas flares fuelling Nigeria’s climate change – BBC News
-
Climate Change2 years ago
Some firms unaware of England’s new single-use plastic ban