“Exceptionally heavy” rainfall that led to deadly flooding across southern Africa in recent weeks was made more intense by a combination of climate change and La Niña.

This is according to a rapid attribution study by the World Weather Attribution service.

From late December 2025 to early January, south-eastern Africa was hit hard by intense downpours that resulted in more than a year’s worth of rain falling in some areas in just a few days, according to the study.

This led to severe flooding that left at least 200 people dead, thousands sheltering in temporary accommodation and tens of thousands of hectares of farmland waterlogged.

The analysis finds that periods of intense rainfall over southern Africa have become 40% more severe since pre-industrial times, according to observations.

The authors say they were unable to calculate how much of this increase was driven specifically by climate change, due to limitations in how climate models simulate African rainfall.

However, the study notes that the researchers “have confidence that climate change has increased both the likelihood and the intensity” of the rainfall.

The authors also note that the El Niño-Southern Oscillation phenomenon played a role in the “devastating” flooding, estimating that a La Niña event made the rainfall around five times more likely.

Major disruption

The heavy rainfall started on 26 December last year and intensified from early January. The most-extreme rainfall took place between 10 and 19 January.

The countries most affected by the floods, and analysed by the study, are Eswatini, Mozambique, South Africa and Zimbabwe, with some areas receiving up to 200mm of rain, according to the study authors.

Study author Bernardino Nhantumbo – a researcher at Mozambique’s National Institute of Meteorology – told a press briefing that in just two or three days, some areas recorded the amount of rainfall that is “expected for the whole rainy season”.

The map below shows the areas most affected by intense rainfall over 10-19 January. Darker blue indicates a greater accumulation of rainfall, while light green indicates less rainfall. The pink box shows the study area.

In Mozambique, the floods damaged nearly 5,000km of roads, which has hindered the transport of goods and affected pharmaceutical supply chains, the study says. In Zimbabwe, bridges, roads and infrastructure were “significantly damaged or destroyed”.

More than 75,000 people have been affected by the floods in Mozambique, according to the study. BBC News reported the floods were the worst seen “in a generation” in the country.

Dr Izidine Pinto, a climate scientist from Mozambique currently working at the Royal Netherlands Meteorological Institute, told a press briefing that the country was particularly affected because it “lies downstream of major river basins”.

The flooding prompted Mozambique’s education minister to consider rescheduling the start of the academic year, according to Channel Africa.

In South Africa, the country’s weather service said that areas receiving more than 50mm of rain over 11-13 January were “widespread”, with some places seeing up to 200mm.

South Africa’s Kruger National Park – the largest national park in South Africa – was severely damaged by floods and temporarily closed after several rivers burst their banks, reported TimesLIVE.

The South African news outlet quoted environment minister Willie Aucamp as saying: “The indication is that it will take as long as five years to repair all the bridges and roads and other infrastructure.”

Extreme rainfall

The peak of the rainy season in southern Africa falls between December and February.

To put the extreme rainfall into its historical context and determine how unlikely it was, the authors analysed a timeseries of 10-day maximum rainfall data for the December-February season.

They find that in today’s climate, extreme rainfall events of the scale seen this year in southern Africa would be expected only once every 50 years.

They add that such events have become “significantly more intense”, with observational data showing a 40% increase in rainfall severity since pre-industrial times.

The map below shows accumulated rainfall over Eswatini, Mozambique, South Africa and Zimbabwe over 10-19 January, as a percentage of the average December-February rainfall for the region over 1991-2020.

Green shading indicates that the rainfall in 2026 was higher than in 1991-2020, while brown indicates that it was lower. The red box indicates the study region.

The study explains that in January and February, rainfall patterns in southern Africa are “strongly influenced” by the El Niño-Southern Oscillation (ENSO), a naturally occurring climate phenomenon that affects global temperatures and regional weather patterns.

La Niña is the “cool” phase of ENSO, which typically brings wetter weather to southern Africa.

Pinto told the press briefing that “most past extreme rainfall events [in the region] have occurred during La Niña years”.

The authors estimate that the current weak La Niña event made the extreme rainfall five times more likely and increased the intensity of the event by around 22%.

For attribution studies, which identify the “fingerprint” of human-caused climate change on extreme weather events, scientists typically use climate models to simulate and compare worlds with and without global warming.

However, many models have limitations in their simulations of African rainfall. In this study, the authors found that the models available to them cannot “adequately capture” the influence of ENSO on rainfall in the region.

Study author Prof Fredi Otto, a professor in climate science at the Imperial College London, told a press briefing that these limitations are “well known”. They stem, in part, because the models were “developed outside of Africa” by modellers with different priorities, she explained.

This means that the authors were unable to calculate how much more intense or likely the rainfall event was specifically as a result of human-caused warming.

However, Otto explained that the authors are “very, very confident that climate change did increase the likelihood and intensity of the rainfall” to some extent. This is because the observations all show an increase in rainfall over time and other existing literature supports this assumption, she added.

She told the press briefing that the results of this study were “definitely not 100% satisfactory”, adding that this study will “definitely not be the last of its kind in this region”.

(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.)

Vulnerability

The study warns that the flooding “exposed deep and persistent social vulnerability in the region”.

The authors say that a large proportion of the population – especially in urban areas – live in poor housing with “inadequate planning and insufficient provision of basic services”.

Paola Emerson, head of office at the UN Office for the Coordination of Humanitarian Affairs (OCHA) in Mozambique, told a UN press briefing about the flooding that nearly 90% of people in the country live in traditional adobe houses that “basically melt after a few days’ rains”.

In a WWA press release, study author Nhantumbo explained:

“When 90% of homes are made of sun-dried earth, they simply cannot withstand this much rain. The structural collapse of entire villages is a stark reminder that our communities and infrastructure are now being tested by weather they are just not designed to endure.”

Study author Renate Meyer – an adviser with the conflict and climate team at the Red Cross Red Crescent Centre – said in a WWA press briefing that the “recurring frequency of hazards such as drought and extreme rainfall have had a significant impact on communities experiencing, amongst others, displacement, health challenges, socioeconomic loss and psychological distress”.

For example, the World Health Organization (WHO) said in a press release that the event had disrupted access to health services and increased the risks of water- and mosquito-borne diseases, as well as respiratory infections across southern Africa.

Meyer explained that the countries included in this study have “substantial populations living below or near the poverty line with limited savings, low insurance cover and a high dependence on climate sensitive livelihoods”.

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The post Climate change and La Niña made ‘devastating’ southern African floods more intense appeared first on Carbon Brief.

Climate change and La Niña made ‘devastating’ southern African floods more intense

Scientists have found that the devastating floods triggered by intense rainfall in Southern Africa in recent weeks were made worse by climate change and have exposed deep social vulnerability, causing a disaster described as “a textbook case of climate injustice”.

The scientists working with the World Weather Attribution (WWA) group said extreme 10-day rainfall events in the region are now about 40% more intense than in pre-industrial times, driven primarily by human-induced climate change – and on this occasion amplified by a weak La Niña pattern. While such rainfall remains relatively rare, the analysis shows it would have been far less severe in a cooler climate.

With more than 100 deaths recorded in Mozambique alone since the rains began in late December, the scientists said the impacts have been compounded by rapid urbanisation, weak planning and high levels of informal settlements, which left communities highly exposed and led to widespread collapses of housing and displacement of families.

Renate Meyer, Southern Africa focal point for the Red Cross Red Crescent Climate Centre, said that when studying extreme events, the WWA group now also looks at people’s vulnerability and exposure, to understand the context and the drivers of risk beyond meteorological conditions.

“Mozambique and parts of South Africa, Eswatini and Zimbabwe are no stranger to floods, but the recurring frequency of the hazards such as drought and intense rainfall have had a significant impact on communities experiencing, amongst others, displacement, health challenges, socio-economic loss and psychological distress,” Meyer told the press launch of the WWA study.

Friederike Otto, professor of climate science at Imperial College London’s Centre for Environmental Policy, said the Southern Africa floods are “a textbook case of climate injustice” because the people of the affected countries have not contributed to climate change, nor are they profiting from using or selling fossil fuels, yet they are the ones losing their lives, homes and livelihoods.

Such disasters can no longer be treated as “acts of God” when they are the direct result of a system built on exploitation and a global failure to phase out fossil fuels, she argued. “We have the know-how and tools to stop this from getting worse,” she added. “We now need the political will that prioritises everyone instead of just the very rich and GDP [gross domestic product]. ”

Climate and social vulnerabilities collide

Separately on Thursday, the charity Water Aid said that in Mozambique and Malawi, more than 800,000 people have been affected, with thousands living in temporary accommodation and shelters, while the number of deaths and people missing continues to rise.

In a statement launching an emergency funding appeal, Water Aid’s Southern Africa director Robert Kampala said the floods are some of the worst the region has ever seen. “This is rapidly becoming a public health crisis,” he added, noting that water sources are become contaminated with floodwater and people are forced to live in cramped shelters, raising the threat of cholera outbreaks and other diseases.

Meyer of the Red Cross said health risks in the region have soared during the floods, with more than 11,500 pregnant women and about 169,000 women of reproductive age among those hit hardest. Many are sheltering in overcrowded conditions with limited access to sexual and reproductive health services, exposing them to stress and increased risk of preterm birth and low birth weight, she told journalists.

Flood risk is higher for people with disabilities when emergency shelters lack ramps and adapted sanitation and support services. “These structural exclusions force people to remain in high-risk locations, converting exposure into avoidable loss,” Meyer said.

Children are also vulnerable, she noted, with around 40% of children in Mozambique currently experiencing malnutrition. “These children are repeatedly exposed to droughts, floods [and] cyclones, with insufficient time or resources to recover nutritionally or physiologically between shocks – and this erodes the possibility of building resilience,” she added.

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Bernardino Nhantumbo, climate researcher with Mozambique’s INAM National Institute of Meteorology in Maputo, said the flooding had caused a “collision” between a climate that grows more dangerous by the day and the region’s deep-rooted social vulnerabilities.

“When 90% of homes are made of sun-dried earth, they simply cannot withstand this much rain,” he said. “The structural collapse of entire villages is a stark reminder that our communities and infrastructure are now being tested by weather they are just not designed to endure.”

Growing needs, shrinking aid

Field reports from aid workers on the ground echo the WWA’s scientific findings. ActionAid Mozambique has said that humanitarian funding cuts and the climate crisis are putting thousands at risk after the dramatic rains and flooding in central and southern parts of the country.

With many people already living in poverty and informal housing, the floods have devastated lives and livelihoods, the aid organisation said. Elsa Manhique, a resident of the Buna area in Manhiça district, told ActionAid she had to “flee with nothing”. “Everything I had was taken by the water. The houses collapsed. We left without documents, without clothes, without anything,” she said.

Marcia Cossa, ActionAid Mozambique’s acting head, said the country is one of the world’s most climate-vulnerable nations, facing cyclones, floods and droughts that are intensifying due to climate change. “As needs grow, international aid and cooperation are shrinking, and that rollback is costing lives,” she added.

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Save the Children, an international aid charity, reported that thousands of children are at risk, with some families rescued by boat from submerged areas. Temporary shelters are overstretched, with some housing both people and livestock, creating serious health and hygiene concerns, the agency warned.

Ilaria Manunza, the charity’s country director, said the floods are unfolding amid a wider humanitarian emergency, pushing already exhausted communities further into crisis. With continued heavy rains forecast and emergency response capacity severely strained, families are being uprooted and children are at extreme risk, she said, calling for urgent support to prevent the emergency escalating further.

The WWA study said strengthening resilience against floods will require full implementation of existing policies and better coordination across river basins. It recommended investing in infrastructure and early warning systems, and building community capacity to prepare for, respond to, and recover from flooding.

The post Southern Africa floods intensified by warming highlight climate injustice, scientists say appeared first on Climate Home News.

Southern Africa floods intensified by warming highlight climate injustice, scientists say

Climate change could lead to half a million more deaths from malaria in Africa over the next 25 years, according to new research.

The study, published in Nature, finds that extreme weather, rising temperatures and shifting rainfall patterns could result in an additional 123m cases of malaria across Africa – even if current climate pledges are met.

The authors explain that as the climate warms, “disruptive” weather extremes, such as flooding, will worsen across much of Africa, causing widespread interruptions to malaria treatment programmes and damage to housing.

These disruptions will account for 79% of the increased malaria transmission risk and 93% of additional deaths from the disease, according to the study.

The rest of the rise in malaria cases over the next 25 years is due to rising temperatures and shifting rainfall patterns, which will change the habitable range for the mosquitoes that carry the disease, the paper says.

The majority of new cases will occur in areas already suitable for malaria, rather than in new regions, according to the paper.

The study authors tell Carbon Brief that current literature on climate change and malaria “often overlooks how heavily malaria risk in Africa is today shaped by climate-fragile prevention and treatment systems”.

The research shows the importance of ensuring that malaria control and primary healthcare is “resilient” to the extreme weather, they say.

Malaria in a warming world

Malaria kills hundreds of thousands of people every year. The World Health Organization (WHO) estimates that 610,000 people died due to the disease in 2024.

In 2024, Africa was home to 95% of malaria cases and deaths. Children under the age of five made up three-quarters of all African malaria deaths.

The disease is transmitted to humans by bites from mosquitoes infected with the malaria parasite. The insects thrive in high temperatures of around 29C and need stagnant or slow-moving water in which to lay their eggs. As such, the areas where malaria can be transmitted are heavily dependent on the climate.

There is a wide body of research exploring the links between climate change and malaria transmission. Studies routinely find that as temperatures rise and rainfall patterns shift, the area of suitable land for malaria transmission is expanding across much of the world.

Study authors Prof Peter Gething and Prof Tasmin Symons are researchers at the Curtin University’s school of population health and the Malaria Atlas Project from the The Kids Research Institute, Australia.

They tell Carbon Brief that this approach does not capture the full picture, arguing that current literature on climate change and malaria “often overlooks how heavily malaria risk in Africa is today shaped by climate-fragile prevention and treatment systems”.

The paper notes that extreme weather events are regularly linked to surges in malaria cases across Africa and Asia. This is, in-part, because storms, heavy rainfall and floods leave pools of standing water where mosquitoes can breed. For example, nearly 15,000 cases of malaria were reported in the aftermath of Cyclone Idai hitting Mozambique in 2019.

However, the study authors also note that weather extremes often cause widespread disruption, which can limit access to healthcare, damage housing or disrupt preventative measures such as mosquito nets. These factors can all increase vulnerability to malaria, driving the spread of the disease.

In their study, the authors assess both the “ecological” effects of climate change – the impacts of temperature and rainfall changes on mosquito populations – and the “disruptive” effects of extreme weather.

Mosquito habitat

To assess the ecological impacts of climate change, the authors first identify how temperature, rainfall and humidity affect mosquito lifecycles and habitats.

The authors combine observational data on temperature, humidity and rainfall, collected over 2000-22, with a range of datasets, including mosquito abundance and breeding habitat.

The authors then use malaria infection prevalence data, collected by the Malaria Atlas Project, which describes the levels of infection in children aged between two and 10 years old.

Symons and Gething explain that they can then use “sophisticated mathematical models” to convert infection prevalence data into estimates of malaria cases.

Comparing these datasets gives the authors a baseline, showing how changes in climate have affected the range of mosquitoes and malaria rates across Africa in the early 21st century.

The authors then use global climate models to model future changes over 2024-49 under the SSP2-4.5 emissions pathway – which the authors describe as “broadly consistent with current international pledges on reduced greenhouse gas emissions”.

The authors also ran a “counterfactual” scenario, in which global temperatures do not increase over the next 25 years. By comparing malaria prevalence in their scenarios with and without climate change, the authors could identify how many malaria cases were due to climate change alone.

Overall, the ecological impacts of climate change will result in only a 0.12% increase in malaria cases by the year 2050, relative to present-day levels, according to the paper.

However, the authors say that this “minimal overall change” in Africa’s malaria rates “masks extensive geographical variation”, with some areas seeing a significant increase in malaria rates and others seeing a decrease.

Disruptive extremes

In contrast, the study estimates that 79% of the future increase in malaria transmission will be due to the “disruptive” impacts of more frequent and severe weather extremes.

The authors explain that extreme weather events, such as flooding and cyclones, can cause extensive damage to housing, leaving people without crucial protective equipment such as mosquito nets.

It can also destroy other key infrastructure, such as roads or hospitals, preventing people from accessing healthcare. This means that in the aftermath of an extreme weather event, people face a greater risk of being infected with malaria.

The climate models run by the study authors project an increase in “disruptive” extreme weather events over the next 25 years.

For example, the authors find that by the middle of the century, cyclones forming in the Indian Ocean will become more intense, with fewer category 1 to category 4 events, but more frequent category 5 events. They also find that climate change will drive an increase in flooding across Africa.

The study finds that without mitigation measures, these disruptive events will drive up the risk of malaria – especially in “main river systems” and the “cyclone-prone coastal regions of south-east Africa”.

Between 2024 and 2050, 67% of people in Africa will see their risk of catching malaria increase as a result of climate change, the study estimates.

The map below shows the percentage change in malaria transmission rate in the 2040s due to the disruptive impacts of climate change alone (left) and a combination of the disruptive and ecological impacts (right), compared to a scenario in which there is no change in the climate. Red and yellow indicate an increase in malaria risk, while blue indicates a reduction.

Colours in lighter shading indicate lower model confidence, while stronger colours indicate higher model confidence.

The maps show that the “disruptive” effects of climate change have a more uniform effect, driving up malaria risk across the entire continent.

However, there is greater regional variation when these effects are combined with “ecological” drivers.

The authors find that warming will increase malaria risk in regions where the temperature is currently too low for mosquitoes to survive. This includes the belt of lower latitude southern Africa, including Angola, southern Democratic Republic of Congo (DRC) and Zambia, as well as highland areas in Burundi, eastern DRC, Ethiopia, Kenya and Rwanda.

Meanwhile, they find that warming will drive down malaria transmission in the Sahel, as temperatures rise above the optimal range for mosquitoes.

Rising risk

The combined “disruptive” and “ecological” impacts of climate change will drive an additional 123m “clinical cases” of malaria across Africa, even if the current climate pledges are met, the study finds.

This will result in 532,000 additional deaths from malaria over the next 25 years, if the disease’s mortality rate remains the same, the authors warn.

The graph below shows the increase in clinical cases of malaria projected across Africa over the next 25 years, broken down into the different ecological (yellow) and disruptive (purple) drivers of malaria risk.

However, the authors stress that there are many other mechanisms through which climate change could affect malaria transmission – for example, through food insecurity, conflict, economic disruption and climate-driven migration.

“Eradicating malaria in the first half of this century would be one of the greatest accomplishments in human history,” the authors say.

They argue that accomplishing this will require “climate-resilient control strategies”, such as investing in “climate-resilient health and supply-chain infrastructure” and enhancing emergency early warning systems for storms and other extreme weather.

Dr Adugna Woyessa is a senior researcher at the Ethiopian Public Health Institute and was not involved in the study. He tells Carbon Brief that the new paper could help inform national malaria programmes across Africa.

He also suggests that the findings could be used to guide more “local studies that address evidence gaps on the estimates of climate change-attributed malaria”.

Study authors Symons and Gething tell Carbon Brief that during their study, they interviewed “many policymakers and implementers across Africa who are already grappling with what climate-resilient malaria intervention actually looks like in practice”.

These interventions include integrating malaria control into national disaster risk planning, with emergency responses after floods and cyclones, they say. They also stress the need to ensure that community health workers are “well-stocked in advance of severe weather”.

The research shows the importance of ensuring that malaria control and primary healthcare is “resilient” to the extreme weather, they say.

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The post Climate change could lead to 500,000 ‘additional’ malaria deaths in Africa by 2050 appeared first on Carbon Brief.

Climate change could lead to 500,000 ‘additional’ malaria deaths in Africa by 2050