The “monsoon downpour” that triggered deadly landslides in Kerala’s Wayanad district last month was made 10% heavier by human-caused climate change, a new rapid attribution study says.
The landslides followed an “exceptional spell of monsoon rain” on 30 July. They have killed at least 230 people, with more than one hundred people still missing and rescue operations ongoing.
Analysis by the World Weather Attribution (WWA) service shows the rainfall that hit Wayanad on 30 July was the region’s third-heaviest period on record, surpassing even the extreme rainfall that led to flooding in Kerala in 2018.
The team of 24 researchers from India, Malaysia, US, Sweden, Netherlands and UK find that downpours of this intensity have already become 17% heavier in the last 45 years.
In a world where average global temperatures are 2C above pre-industrial levels, they estimate that extreme single-day bursts of rainfall in Kerala could become a further 4% heavier, potentially leading to even more catastrophic landslides.
The study also looks at other “mixed” factors that may have contributed to the high casualties and Wayanad’s “increased susceptibility” to landslides. These include a 62% loss of forest cover in the district and warnings that “failed to reach many people”.
Slippery slope
Wayanad is a mountainous district in northern Kerala in India’s Western Ghats – a chain of mountains older than the Himalaya that runs parallel to the country’s western coast.
With its high elevation and steep slopes – combined with a tendency to receive “prolonged” rainfall and widespread changes to its natural vegetation – Wayanad is highly landslide-prone. It is the most susceptible district to landslides in Kerala, which accounted for 59% of the country’s landslides over 2015-22.
From 22 June onwards, Wayanad saw “nearly continuous” monsoon rainfall, the WWA study says – with some areas recording over 1.8 metres of rain in just a month.
On 30 July, Wayanad witnessed what study author Dr Mariam Zachariah – a research associate at Imperial College’s London’s Grantham Institute for Climate Change – calls “an extreme burst” of more than 140mm of rain in a single day. This is equivalent to nearly a quarter of the rain London receives all year. This rain landed on loose, erodible soils already saturated by two months of monsoon rains.
The first landslide that began at an altitude of 1,550 metres struck the village of Mundakkai at midnight on 30 July, followed by three more landslides within three hours, hitting the villages of Chooralmala and Attamala.
Torrents of mud, water and rock buried several neighbourhoods, swept away victims and collapsed an arterial bridge, delaying rescue operations to the hardest-hit areas.
Rescuers at a damaged house in Kerala state, India, after a landslide on 31 July, 2024. Credit: Rafiq Maqbool / Alamy Stock Photo
While state authorities say that the death toll at the time of writing is 231, media reports suggest that the actual number of lives lost to the landslides is greater than 400 – disproportionately impactingmigrant workers working in farms, holiday resorts and tea plantations.
In a press briefing, study author Prof Arpita Mondal from the Indian Institute of Technology Bombay said the “scale of the event was so huge that the debris registered a flow of several kilometres”, adding that “body parts have been recovered from downstream rivers as far as tens of kilometres from the location of the landslides”.
The event, she says, was “particularly devastating to two villages – Mundakkai and Chooralmala”, with one official telling News Minute that “I don’t think the Chooralmala ward will exist anymore”.
Monsoon downpour
To put Wayanad’s intense rainfall into its historical context and determine how unlikely it was, the authors analysed a timeseries of one-day maximum rainfall during the June-to-September monsoon season, focusing on northern Kerala.
They find that 140mm of rainfall hit northern Kerala on 30 July 2024, ranking as the third heaviest one-day rainfall event in a record stretching back to 1901.
The map below shows total rainfall on 30 July 2024 in northern Kerala, based on data from the Indian Meteorological Department. Dark blue indicates a high total daily rainfall and yellow indicates a low total. The study region is shown in red on the map.
Total rainfall on 30 July 2024, based on data from the Indian Meteorological Department. Dark blue indicates a high total daily rainfall and yellow indicates a low total. The study region is shown in red. Source: WWA (2024)
The authors find that in today’s climate, this intense one-day rainfall is a one-in-50 year event.
Separately, using satellite observations, the authors find that heavy one-day rainfall events over northern Kerala have become about 17% more intense in the last 45 years, in which time the global climate has warmed by around 0.85C.
Attribution
Attribution is a fast-growing field of climate science that aims to identify the “fingerprint” of climate change on extreme-weather events, such as heatwaves and droughts.
In this study, the authors investigated the impact of climate change specifically on the heavy rainfall in northern Kerala on 30 July 2024.
To conduct attribution studies, scientists use climate models to compare the world as it is today to a “counterfactual” world, without the 1.3C of human-caused warming.
The authors find that climate change made the intense rainfall on 30 July around 10% more intense.
The authors note that Kerala is a mountainous region with “complex rainfall-climate dynamics” and explain that there is a high level of uncertainty in the model results.
However, Zachariah told the press briefing that the study findings are “consistent with Clausius Clapeyron relationship”, which states that the air can generally hold around 7% more moisture for every 1C of temperature rise.
The authors also investigate how rainfall intensity might change as the planet continues to warm. They find that if the planet were to warm to 2C above pre-industrial temperatures, rainfall intensity in northern Kerala is expected to become a further 4% more intense.
The study says that this increase in rainfall intensity is “likely to increase the potential number of landslides that could be triggered in the future”.
(These findings are yet to be published in a peer-reviewed journal. However, the methods used in the analysis have been published in previous attribution studies.)
Wayanad is known for its dense forests and rich biodiversity, but it has also seen significant deforestation and land-use change.
While heavy rainfall was “a trigger” for the devastating landslides, human intervention “has played an important role, there’s no doubt about it”, says Madhavan Rajeevan, India’s former Earth sciences secretary who was not involved in the study. He tells Carbon Brief:
“In many interviews with local people, they say that [large-scale] construction work was going on in the worst-hit areas. And that construction [was done] by removing the local [Indigenous people] staying in the forest. But the landslide doesn’t differentiate between rich and poor. If there was no substantial human intervention in that area for the last four or five years, I’m very sure this landslide would not have happened.”
Between 1950 and 2018, Wayanad lost 62% of its forest cover while land under tea plantations grew by 1,800%, according to one study. The district’s high slopes are also host to coffee, pepper, tea and cardamom plantations, as well as being dotted by luxury resorts.
At the same time, a rise in construction and quarrying for building stones in recent years has “raise[d] concerns” among scientists about the impacts on the stability of hill slopes in the area.
On 31 July, the day after disaster struck, India’s climate ministry issued the sixth draft of a notification to classify parts of the Western Ghats as ecologically sensitive areas (ESAs), 14 years after experts had recommended curbs on development in the region.
Environmental lawyer Shibani Ghosh tells Carbon Brief that, to date, 72,000 square kilometres of the Western Ghats identified by these experts “do not even fall within the ambit of any proposed conservation scheme”.
While environmentalists still have “serious apprehensions” about the area that will be excluded from the Western Ghats ESA in the new draft, “had it been declared [even in its unsatisfactory form] by now, environmentally harmful activities would have been regulated, and perhaps the impact of these natural calamities would have been much less”, she adds.
Rajeevan, additionally, points to how the monsoon has changed in Kerala. He says:
“We know that seasonal rainfall is very high in the west coast, it rains continuously for many days and many hours, but the amount used to be very small: in millimetres per hour. But recent studies are suggesting that these shallow clouds are changing into deep convective clouds that drop very heavy rain in a very short spell, and that could be attributed to warming over the Arabian Sea.”
At the same time, forecasting is another issue that the study raises, drawing attention to the fact that warnings failed to reach many and impacts were not specifically spelt out.
Rescuers wait to cross a river in Kerala state, India after a landslide on 31 July 2024. Credit: Rafiq Maqbool / Alamy Stock Photo
In the aftermath of the landslides, whether meteorological authorities warned of heavy rains became the subject of parliamentary debate. But Rajeevan points out that accurate rain warnings alone are not enough:
“Red alerts and yellow alerts for the whole state or a few districts do not translate into a landslide warning. A district collector cannot translate them or take a decision. The Geological Survey of India issued a warning, but it was not alarming and a sophisticated, real-time landslide alert system needs a lot of money.
“The best solution is to identify and rehabilitate people living in landslide prone areas and to not trouble them by removing their forests.”
In Kenya’s Laikipia County where temperatures can reach as high as 30 degrees Celsius, a local building technology is helping homes stay cooler while supporting education, creating jobs and improving the livelihoods and resilience of community residents, Climate Home News found on a visit to the region.
Situated in a semi-arid region, houses in Laikipia are mostly built with wood or cement blocks with corrugated iron sheets for roofing. This building method usually leaves the insides of homes scorching hot – and as global warming accelerates, the heat is becoming unbearable.
Peter Muthui, principal of Mukima Secondary School in Laikipia County, lived in these harsh conditions until 2023, when the Laikipia Integrated Housing Project began in his community.
The project uses compressed earth block (CEB) technology, drawing on traditional building methods and local materials – including soil, timber, grass and cow dung – to keep buildings cool in the highland climate. The thick earth walls provide insulation against the heat.
Peter Muthui, principal of Mukima Secondary School in Laikipia County, stands in front of classroom blocks built with compressed earth blocks (Photo: Vivian Chime)
Peter Muthui, principal of Mukima Secondary School in Laikipia County, stands in front of classroom blocks built with compressed earth blocks (Photo: Vivian Chime)
“Especially around the months of September all the way to December, it is very, very hot [in Laikipia], but as you might have noticed, my house is very cool even during the heat,” Muthui told Climate Home News.
His school has also deployed the technology for classrooms and boarding hostels to ensure students can carry on studying during the hottest seasons of the year. This way, they are protected from severe conditions and school closures can be avoided. In South Sudan, dozens of students collapsed from heat stroke in the capital Juba earlier this year, causing the country to shutter schools for weeks.
COP30 sees first action call on sustainable, affordable housing
The buildings and construction sector accounts for 37% of global emissions, making it the world’s largest emitter of greenhouse gases, according to the UN Environment Programme (UNEP). While calls to decarbonise the sector have grown, meaningful action to cut emissions has remained limited.
At COP28 in Dubai, the United Arab Emirates and Canada launched the Cement and Concrete Breakthrough Initiative to speed up investment in the technologies, policies and tools needed to put the cement and concrete industry on a net zero-emissions path by 2050.
Canada’s innovation minister, François-Philippe Champagne, said the initiative aimed to build a competitive “green cement and concrete industry” which creates jobs while building a cleaner future.
Coordinated by UNEP’s Global Alliance for Buildings and Construction, the council has urged countries to embed climate considerations into affordable housing from the outset, “ensuring the drive to deliver adequate homes for social inclusion goes hand in hand with minimising whole-life emissions and environmental impacts”.
Homes built with compressed earth blocks in Laikipia (Photo: Julián Reingold)
Homes built with compressed earth blocks in Laikipia (Photo: Julián Reingold)
With buildings responsible for 34% of energy-related emissions and 32% of global energy demand, and 2.8 billion people living in inadequate housing, the ICBC stressed that “affordable, adequate, resource-efficient, low-carbon, climate-resilient and durable housing is essential to a just transition, the achievement of the Sustainable Development Goals and the effective implementation of the Paris Agreement”.
Compressed earth offers local, green alternative
By using locally sourced materials, and just a little bit of cement, the compressed earth technology is helping residents in Kenya’s Laikipia region to build affordable, climate-smart homes that reduce emissions and environmental impacts while creating economic opportunities for local residents, said Dacan Aballa, construction manager at Habitat for Humanity International, the project’s developers.
Aballa said carbon emissions in the construction sector occur all through the lifecycle, from material extraction, processing and transportation to usage and end of life. However, by switching to compressed earth blocks, residents can source materials available in their environment, avoiding nearly all of that embedded carbon pollution.
According to the World Economic Forum (WEF), global cement manufacturing is responsible for about 8% of total CO2 emissions, and the current trajectory would see emissions from the sector soar to 3.8 billion tonnes per year by 2050 – a level that, compared to countries, would place the cement industry as one of the world’s top three or four emitters alongside the US and China.
Comparing compressed earth blocks and conventional materials in terms of carbon emissions, Aballa said that by using soil native to the area, the process avoids the fossil fuels that would normally have been used for to produce and transport building materials, slashing carbon and nitrogen dioxide emissions.
The local building technology also helps save on energy that would have been used for cooling these houses as well as keeping them warm during colder periods, Aballa explained.
Justin Atemi, water and sanitation officer at Habitat for Humanity, said the brick-making technique helps reduce deforestation too. This is because the blocks are left to air dry under the sun for 21 days – as opposed to conventional fired-clay blocks that use wood as fuel for kilns – and are then ready for use.
Women walk passed houses in the village of Kangimi, Kaduna State, Nigeria (Photo: Sadiq Mustapha)
Traditional knowledge becomes adaptation mechanism
Africa’s red clay soil was long used as a building material for homes, before cement blocks and concrete became common. However, the method never fully disappeared. Now, as climate change brings higher temperatures, this traditional building approach is gaining renewed attention, especially in low-income communities in arid and semi-arid regions struggling to cope with extreme heat.
From Kenya’s highlands to Senegal’s Sahelian cities, compressed earth construction is being repurposed as a low-cost, eco-friendly option for homes, schools, hospitals – and even multi-storey buildings.
Senegal’s Goethe-Institut in Dakar was constructed primarily using compressed earth blocks. In Mali, the Bamako medical school, which was built with unfired mud bricks, stays cool even during the hottest weather.
And more recently, in Nigeria’s cultural city of Benin, the just-finished Museum of West African Art (MOWA) was built using “rammed earth” architecture – a similar technology that compresses moist soil into wooden frames to form solid walls – making it one of the largest such structures in Africa.
David Sathuluri is a Research Associate and Dr. Marco Tedesco is a Lamont Research Professor at the Lamont-Doherty Earth Observatory of Columbia University.
As climate scientists warn that we are approaching irreversible tipping points in the Earth’s climate system, paradoxically the very technologies being deployed to detect these tipping points – often based on AI – are exacerbating the problem, via acceleration of the associated energy consumption.
The UK’s much-celebrated £81-million ($109-million) Forecasting Tipping Points programme involving 27 teams, led by the Advanced Research + Invention Agency (ARIA), represents a contemporary faith in technological salvation – yet it embodies a profound contradiction. The ARIA programme explicitly aims to “harness the laws of physics and artificial intelligence to pick up subtle early warning signs of tipping” through advanced modelling.
We are deploying massive computational infrastructure to warn us of climate collapse while these same systems consume the energy and water resources needed to prevent or mitigate it. We are simultaneously investing in computationally intensive AI systems to monitor whether we will cross irreversible climate tipping points, even as these same AI systems could fuel that transition.
The computational cost of monitoring
Training a single large language model like GPT-3 consumed approximately 1,287 megawatt-hours of electricity, resulting in 552 metric tons of carbon dioxide – equivalent to driving 123 gasoline-powered cars for a year, according to a recent study.
GPT-4 required roughly 50 times more electricity. As the computational power needed for AI continues to double approximately every 100 days, the energy footprint of these systems is not static but is exponentially accelerating.
And the environmental consequences of AI models extend far beyond electricity usage. Besides massive amounts of electricity (much of which is still fossil-fuel-based), such systems require advanced cooling that consumes enormous quantities of water, and sophisticated infrastructure that must be manufactured, transported, and deployed globally.
The water-energy nexus in climate-vulnerable regions
A single data center can consume up to 5 million gallons of drinking water per day – sufficient to supply thousands of households or farms. In the Phoenix area of the US alone, more than 58 data centers consume an estimated 170 million gallons of drinking water daily for cooling.
The geographical distribution of this infrastructure matters profoundly as data centers requiring high rates of mechanical cooling are disproportionately located in water-stressed and socioeconomically vulnerable regions, particularly in Asia-Pacific and Africa.
At the same time, we are deploying AI-intensive early warning systems to monitor climate tipping points in regions like Greenland, the Arctic, and the Atlantic circulation system – regions already experiencing catastrophic climate impacts. They represent thresholds that, once crossed, could trigger irreversible changes within decades, scientists have warned.
Yet computational models and AI-driven early warning systems operate according to different temporal logics. They promise to provide warnings that enable future action, but they consume energy – and therefore contribute to emissions – in the present.
This is not merely a technical problem to be solved with renewable energy deployment; it reflects a fundamental misalignment between the urgency of climate tipping points and the gradualist assumptions embedded in technological solutions.
The carbon budget concept reveals that there is a cumulative effect on how emissions impact on temperature rise, with significant lags between atmospheric concentration and temperature impact. Every megawatt-hour consumed by AI systems training on climate models today directly reduces the available carbon budget for tomorrow – including the carbon budget available for the energy transition itself.
The governance void
The deeper issue is that governance frameworks for AI development have completely decoupled from carbon budgets and tipping point timescales. UK AI regulation focuses on how much computing power AI systems use, but it does not require developers to ask: is this AI’s carbon footprint small enough to fit within our carbon budget for preventing climate tipping points?
There is no mechanism requiring that AI infrastructure deployment decisions account for the specific carbon budgets associated with preventing different categories of tipping points.
Meanwhile, the energy transition itself – renewable capacity expansion, grid modernization, electrification of transport – requires computation and data management. If we allow unconstrained AI expansion, we risk the perverse outcome in which computing infrastructure consumes the surplus renewable energy that could otherwise accelerate decarbonization, rather than enabling it.
With global consensus over climate action faltering on the accord’s 10th anniversary, experts say “coalitions of the willing” should move faster and with more ambition
Rising demand in Southeast Asia and India is expected to prevent coal use from falling significantly this decade, the International Energy Agency predicts
What would it mean to resolve the paradox?
Resolving this paradox requires, for example, moving beyond the assumption that technological solutions can be determined in isolation from carbon constraints. It demands several interventions:
First, any AI-driven climate monitoring system must operate within an explicitly defined carbon budget that directly reflects the tipping-point timescale it aims to detect. If we are attempting to provide warnings about tipping points that could be triggered within 10-20 years, the AI system’s carbon footprint must be evaluated against a corresponding carbon budget for that period.
Second, governance frameworks for AI development must explicitly incorporate climate-tipping point science, establishing threshold restrictions on computational intensity in relation to carbon budgets and renewable energy availability. This is not primarily a “sustainability” question; it is a justice and efficacy question.
Third, alternative models must be prioritized over the current trajectory toward ever-larger models. These should include approaches that integrate human expertise with AI in time-sensitive scenarios, carbon-aware model training, and using specialized processors matched to specific computational tasks rather than relying on universal energy-intensive systems.
The deeper critique
The fundamental issue is that the energy-system tipping point paradox reflects a broader crisis in how wealthy nations approach climate governance. We have faith that innovation and science can solve fundamental contradictions, rather than confronting the structural need to constrain certain forms of energy consumption and wealth accumulation. We would rather invest £81 million in computational systems to detect tipping points than make the political decisions required to prevent them.
The positive tipping point for energy transition exists – renewable energy is now cheaper than fossil fuels, and deployment rates are accelerating. What we lack is not technological capacity but political will to rapidly decarbonize, as well as community participation.
Deploying energy-intensive AI systems to monitor tipping points while simultaneously failing to deploy available renewable energy represents a kind of technological distraction from the actual political choices required.
The paradox is thus also a warning: in the time remaining before irreversible tipping points are triggered, we must choose between building ever-more sophisticated systems to monitor climate collapse or deploying available resources – capital, energy, expertise, political attention – toward allaying the threat.
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