“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”.
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
Climate Change
In a Years-Long Fight, the Illinois Environmental Justice Movement Gets a Win
A bill, newly passed by legislators, will expand the state’s capacity to enforce limits on health-harming emissions in overburdened communities.
After years of fighting to curb toxic pollution in communities of color, Illinois activists are celebrating a step forward.
In a Years-Long Fight, the Illinois Environmental Justice Movement Gets a Win
Climate Change
Appeals Court Affirms Dismissal of Youth Climate Case Against Trump
The lead attorney for the 22 plaintiffs said the court has “slammed the courthouse doors on children fighting for their lives.”
A federal appeals court has sided with the Trump administration and 19 Republican-led states in a constitutional challenge to several of President Donald Trump’s executive orders designed to boost fossil fuels, concluding that the youth plaintiffs failed to bring a viable case against the federal government. In affirming a lower court’s dismissal of the lawsuit, called Lighthiser v. Trump, the appeals court said that it was not the role of the judiciary to supervise government energy policy.
Appeals Court Affirms Dismissal of Youth Climate Case Against Trump
Climate Change
Investor climate group closes down, blaming “limits” of shareholder activism
In 2021, amidst a wave of corporate net-zero targets, a campaign group called Investors for Paris Compliance was set up in British Columbia, aiming to use investor pressure to hold Canadian companies to account on their climate promises.
In the five years since, the group has notched up several wins: pressuring National Bank into providing $20 billion of finance to renewable energy, getting Royal Bank of Canada to improve its green finance labels and persuading 20-25% of investors to regularly back climate proposals at annual general meetings (AGMs) for shareholders.
But last month, the group’s then executive director Matt Price put out a statement saying it was shutting down. Despite some progress, Price explained, his organisation had concluded that “investor accountability has reached its limits”.
Companies and their investors often understand that climate change threatens the economic system, Price said. But, he added, they do not respond adequately because they are worried that, if they do, their competitors will not put in as much effort and could therefore gain a financial advantage.
This “tragedy of the commons” situation cannot be fixed by shareholder advocacy, Price said, but instead needs litigation, regulatory action and accountability mechanisms. “Some of our team will take those things on in new initiatives,” he said.
Price’s words echo the findings of a London School of Economics (LSE) report published last month, based on workshops with asset owners and managers in New York, Amsterdam, London and Singapore.
Government policy key
The LSE report noted that “action by investors on climate change is severely constrained by their duties, the limited tools at their disposal and the pathways of technology development”. To be effective, pressure from climate-conscious investors must be coupled with government policy that incentivises green investment and technological innovation, the authors concluded.
An investigation by the Guardian recently found that, despite overwhelming shareholder support for its climate action plan, Australian mining company BHP has carried on buying polluting diesel trucks instead of electric ones. The Australian government subsidises diesel, saving BHP hundreds of millions of dollars a year.
As EU acts to stop greenwash, funds drop climate claims from their names
Lindsey Stewart, director of institutional insights for investment research firm Morningstar, told Climate Home News that investor activism does work but it “doesn’t do everything that people expected it to do towards the beginning of the 2020s”.
“There is a limit to what can be achieved by minority shareholders exercising their votes and engaging with companies. Quite a lot, it does seem, is reliant on the legal and regulatory framework,” he said, adding that the closure of Investors for Paris Compliance shows this “realisation is sinking in a lot more than perhaps it was in 2020, 2021, 2022”.
Decline of investor activism
Stewart said that in the early 2020s, investor activists were pushing companies for “things that were sort of already on the regulatory conveyor belt anyway”, like companies setting targets for their operational (Scope 1 and 2) emissions, disclosing their carbon footprints, and assessing their exposure to risk from climate change.
With this low-hanging fruit picked, green-minded investors have moved on to make demands that are more controversial and have received less support from other investors, he said. He gave examples of just transition reporting, green capital expenditure financing ratios for banks and disclosing emissions from the use of products a company sells, known as Scope 3 emissions.
On top of this, Stewart said, there has been pressure from the “right-wing political establishment in the US” against investors taking climate change into consideration. BlackRock, which manages $9.5 trillion of assets, has walked back its climate commitments after pressure from US Republicans.
More fundamentally, Stewart described the idea that fossil fuel majors would dismantle their oil and gas business and transform into renewables companies as a “pipe dream on the part of environmentalists”. “Why would they have the skill or capability, or even the stakeholder backing, to completely transform a business of that size?” he asked.
Shareholder activism is only possible at privately owned and listed companies, while most investment in oil and gas is now coming from state-owned companies, like Saudi Arabia’s Aramco. In 2025, less than a quarter of investment was from oil majors like BP and Shell.
Business backlash shows power
Yet despite the uphill climb, Mark van Baal defends shareholder activism. He runs an Amsterdam-based campaign group called Follow This, which has tried to get investors to vote for pro-climate resolutions at the AGMs of oil and gas multinationals.
He accepts that success peaked around 2021, but says the effort oil and gas firms are now putting into winning over shareholders and discouraging pro-climate resolutions – which he characterised as “the Empire Strikes Back” – shows the power of shareholder activism, which was previously underestimated.

In January 2024, ExxonMobil sued Follow This, aiming to block the group’s climate resolution. Fearing the case would end up in the Supreme Court, where conservative judges could set an anti-climate precedent, Follow This withdrew the resolution.
But, said van Baal, although the legal battle created a “chilling effect among investors”, it is a “proof point that shareholder pressure works and that they’re really afraid of the shareholders”.
Vote, don’t sell
Stewart and van Baal both agreed that selling, or threatening to sell off shares is not an effective way to change a company’s behaviour.
It allows less climate-conscious investors to buy the shares, they said, adding that there is no evidence that threats to sell shares and therefore lower the valuation over climate concerns have influenced company management.
Van Baal said the share price is set by short-term traders, not long-term shareholders like the pension funds he works with.
How Shell is still benefiting from offloaded Niger Delta oil assets
Nonetheless, investors’ engagement should be forceful, van Baal insisted – and not just within their comfort zone of talking to management about sustainability behind closed doors without voting for it at AGMs. “Shareholder democracy is the only democracy where voting is called escalation,” he said.
The Follow This website says that only investors can stop fossil fuel companies destroying the planet. “Marches didn’t change their minds. Lawsuits didn’t stop them. But shareholders can,” it trumpets.
But van Baal told Climate Home News this wording is “too strong” and may have to be revised, adding that shareholder activism just “fits me more than gluing myself to roads” and is a tactic he “stumbled on” 11 years ago.
Legal, political and investor activism can reinforce each other, he added. When Friends of the Earth sued Shell alleging inadequate climate action, for example, the green group’s lawyers cited the company’s rejection of a Follow This resolution as evidence. “The pressure needs to come from all sides,” van Baal said.
The post Investor climate group closes down, blaming “limits” of shareholder activism appeared first on Climate Home News.
Investor climate group closes down, blaming “limits” of shareholder activism
-
Climate Change10 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Greenhouse Gases10 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Greenhouse Gases2 years 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 Change2 years 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 Change2 years ago
Bill Discounting Climate Change in Florida’s Energy Policy Awaits DeSantis’ Approval
-
Renewable Energy7 months agoSending Progressive Philanthropist George Soros to Prison?
-
Carbon Footprint2 years agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits
-
Greenhouse Gases11 months ago
嘉宾来稿:探究火山喷发如何影响气候预测







