The extreme rainfall that hit Afghanistan, Pakistan and Iran in April and May this year was made twice as likely by El Niño, a new rapid attribution study shows.
The World Weather Attribution service finds that spring rainfall over the region has become 25% heavier over the past 40 years.
As climate models were unable to reproduce this trend, the authors were unable to assess the impact of rising global temperatures on the event. However, a study author tells Carbon Brief that she “would be extremely surprised if climate change is not at least part of this trend”..
In contrast, the authors were able to identify the influence of the strong El Niño event that has been underway in the Pacific Ocean since the autumn of 2023.
They find that such heavy rainfall would be expected once every 20 years in the absence of El Niño, but this frequency rises to once every 10 years when an event occurs.
Flash flooding
In the spring of 2024, a series of unseasonably early spring storms swept across large parts of central Asia, causing severe flooding which destroyed homes and crops, and killed thousands of people.
In Pakistan, the first spell of intense rainfall began on 12 April. The resulting flooding damaged more than 450 schools and 5,000 houses, and killed more than 100 people. Subsequent periods of heavy rainfall across the country caused further damage to buildings and crops, destroying huge fields of wheat that were ready for harvest.
The flooding “has resulted in significant economic losses for local farmers and communities, compounding the losses from the rain-related incidents”, the UN Office for the Coordination of Humanitarian Affairs warned.
Afghanistan also suffered a series of deadly floods. After a dry winter, which made the soil less able to absorb rainfall, the country was hit by waves of intense rainfall throughout much of April and May,
About 70 people were killed in April after flash floods destroyed about 2,000 homes, three mosques and four schools. On 10 May, another period of intense rainfall hit the country – especially in the north-east, resulting in hundreds of fatalities and many more missing people. Around 9,100 livestock and 20,800 acres of agricultural land were destroyed.
Five days later, the International Federation of Red Cross and Red Crescent Societies warned that 25 out of 34 provinces in Afghanistan had been affected by flooding, adding that “thousands of displaced people have no homes to return to after their houses were swept away”. The organisation also warned:
“This latest disaster is happening within the context of what is already one of the world’s worst humanitarian crises, where communities are already barely able to cope.”
Meanwhile, the Guardian reported that “in a country with a health system already on its knees, some health facilities were rendered non-operational last week by the flooding”.
Similarly, intense rainfall and flooding killed multiple people in Iran. The
Iran International Newsroom blamed “government mismanagement and flawed urban planning” for “exacerbating” the intense rainfall.
The study authors decided to focus on April-May rainfall in a region centred on Afghanistan, bounded by Iran on the west and Pakistan on the east.
The map below shows the difference in April-May total rainfall between 2024 and the 1991-2020 average, where blue indicates that 2024 saw heavier than average rainfall, and red indicates lighter than average rainfall. The region analysed in this study – covering parts of Afghanistan, Pakistan and Iran – is outlined in red.
The region’s main winter rainfall season runs from November to early April, meaning that this year’s intense rainfall was unusually early, the study says.
Attribution
The spring flooding over Afghanistan, Pakistan and Iran was “incredibly deadly”, according to the. To determine how likely this period of intense rainfall was, the authors analysed a timeseries of observed rainfall data to put the event into its historical context.
The graph below shows April-May rainfall from 1950 to the present day over the study region. The blue and orange lines indicate different datasets.
The observational data shows that April-May rainfall in the region has become, on average, 25% heavier over the past 40 years.
The authors conducted an attribution study to identify the “fingerprint” of climate change on the extreme rainfall trend. They used models to compare the world as it is today – which has already warmed by around 1.2C because of human activity – to a “counterfactual” world without climate change.
However, the climate models used in this analysis did not consistently reproduce the trends shown by observed data.
“We can’t formally attribute it because the models don’t reproduce these trends,” Dr Friederike Otto – senior lecturer in climate science at the Grantham Institute for Climate Change and the Environment at Imperial College London and co-author of the study – told Carbon Brief at a press briefing.
However, Otto – who is also a Carbon Brief contributing editor – explained that climate change is known to make individual storms more intense. “So I would be extremely surprised if climate change is not at least part of this trend,” she added.
The authors also investigate the impact of El Niño – a global weather phenomenon that originates in the Pacific Ocean – on rainfall in the region. The world has been experiencing El Niño conditions since around October 2023 and is now showing signs of ending.
Dr Mariam Zachariah, who is also study author from the Grantham Institute, told Carbon Brief that El Niño leads to warmer sea surface temperatures over the western Indian ocean, which are a “known driver” of extreme rainfall over the study region.
Using a series of statistical models, the authors determined that an El Niño during the winter (December-February) often leads to an increase in rainfall over the study period during April and May.
The 2024 spring rainfall over Afghanistan, Pakistan and Iran was not “particularly rare” in today’s climate, and could be expected to occur roughly once every 10 years if only El Niño years are considered, the authors find.
Under “neutral” conditions in the Pacific Ocean, similar periods of heavy rainfall are expected roughly once every 20 years, they add.
They conclude that El Niño doubled the likelihood of the extreme rainfall that hit Afghanistan, Pakistan and Iran in spring 2024.
(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
Afghanistan ranks fourth on the list of countries most at risk of a crisis, and eighth on the Notre Dame Global Adaptation Initiative index of countries most vulnerable and least prepared to adapt to climate change.
However, the country has been absent from COP climate summits since the Taliban took over in 2021. No foreign government has formally recognised Taliban leadership and it does not have a seat at the UN General Assembly.
The Taliban’s takeover has impacted Afghanistan’s access to climate finance. The country’s climate plan estimates it needs $20.6bn over 2021-30. But around 32 large environmental programmes worth more than $800m were suspended when the Taliban took over, including a major rural solar installation project backed by the Green Climate Fund.
Nevertheless, the country is still receiving some climate finance. A recent freedom-of-information request by Carbon Brief shows that the UK government has opted to meet their £11.6bn climate finance target by “redirecting” or “relabelling” existing funds as “climate finance”, while failing to commit new money in sufficient volumes.
This includes reclassifying nearly £500m of aid for war-torn and impoverished countries, including Afghanistan, as “climate finance”.
And, in late April this year, the Taliban initiated its first discussions with the UN, donors and non-governmental organisations about the implications of climate change in Afghanistan, as confirmed by organisers.
However, in the meantime, Afghanistan remains highly vulnerable to the impacts of climate change.
The authors say that many residents of Afghanistan – as well as Pakistan and Iran – are “highly vulnerable” to flash flooding, as many of them live on river basins that are highly vulnerable to flash floods.
Maja Vahlberg – a climate risk consultant from the Red Cross Red Crescent Climate Centre and author on the study – told Carbon Brief that “marginalised communities” were among the most severely impacted by the flooding.
The study adds that “displaced populations were particularly impacted, especially as limited essential infrastructure was destroyed and already vulnerable populations were exposed to more waterborne diseases”.
Vahlberg told Carbon Brief that, across the region, there is “limited” data sharing and flood risk management, meaning that flood early warning systems are “significantly less efficient” than they could be.
The study concludes that there are “ample opportunities to improve climate adaptation and resilience”, including “increasing the coverage of early warning systems, and improving flood risk management policy and planning”.
The post Afghanistan’s ‘deadly’ early spring rainfall made twice as likely by El Niño appeared first on Carbon Brief.
Afghanistan’s ‘deadly’ early spring rainfall made twice as likely by El Niño
Drought and heatwaves occurring together – known as “compound” events – have “surged” across the world since the early 2000s, a new study shows.
Compound drought and heat events (CDHEs) can have devastating effects, creating the ideal conditions for intense wildfires, such as Australia’s “Black Summer” of 2019-20 where bushfires burned 24m hectares and killed 33 people.
The research, published in Science Advances, finds that the increase in CDHEs is predominantly being driven by events that start with a heatwave.
The global area affected by such “heatwave-led” compound events has more than doubled between 1980-2001 and 2002-23, the study says.
The rapid increase in these events over the last 23 years cannot be explained solely by global warming, the authors note.
Since the late 1990s, feedbacks between the land and the atmosphere have become stronger, making heatwaves more likely to trigger drought conditions, they explain.
One of the study authors tells Carbon Brief that societies must pay greater attention to compound events, which can “cause severe impacts on ecosystems, agriculture and society”.
Compound events
CDHEs are extreme weather events where drought and heatwave conditions occur simultaneously – or shortly after each other – in the same region.
These events are often triggered by large-scale weather patterns, such as “blocking” highs, which can produce “prolonged” hot and dry conditions, according to the study.
Prof Sang-Wook Yeh is one of the study authors and a professor at the Ewha Womans University in South Korea. He tells Carbon Brief:
“When heatwaves and droughts occur together, the two hazards reinforce each other through land-atmosphere interactions. This amplifies surface heating and soil moisture deficits, making compound events more intense and damaging than single hazards.”
CDHEs can begin with either a heatwave or a drought.
The sequence of these extremes is important, the study says, as they have different drivers and impacts.
For example, in a CDHE where the heatwave was the precursor, increased direct sunshine causes more moisture loss from soils and plants, leading to a drought.
Conversely, in an event where the drought was the precursor, the lack of soil moisture means that less of the sun’s energy goes into evaporation and more goes into warming the Earth’s surface. This produces favourable conditions for heatwaves.
The study shows that the majority of CDHEs globally start out as a drought.
In recent years, there has been increasing focus on these events due to the devastating impact they have on agriculture, ecosystems and public health.
In Russia in the summer of 2010, a compound drought-heatwave event – and the associated wildfires – caused the death of nearly 55,000 people, the study notes.
The record-breaking Pacific north-west “heat dome” in 2021 triggered extreme drought conditions that caused “significant declines” in wheat yields, as well as in barley, canola and fruit production in British Columbia and Alberta, Canada, says the study.
Increasing events
To assess how CDHEs are changing, the researchers use daily reanalysis data to identify droughts and heatwaves events. (Reanalysis data combines past observations with climate models to create a historical climate record.) Then, using an algorithm, they analyse how these events overlap in both time and space.
The study covers the period from 1980 to 2023 and the world’s land surface, excluding polar regions where CDHEs are rare.
The research finds that the area of land affected by CDHEs has “increased substantially” since the early 2000s.
Heatwave-led events have been the main contributor to this increase, the study says, with their spatial extent rising 110% between 1980-2001 and 2002-23, compared to a 59% increase for drought-led events.
The map below shows the global distribution of CDHEs over 1980-2023. The charts show the percentage of the land surface affected by a heatwave-led CDHE (red) or a drought-led CDHE (yellow) in a given year (left) and relative increase in each CDHE type (right).
The study finds that CDHEs have occurred most frequently in northern South America, the southern US, eastern Europe, central Africa and south Asia.
Threshold passed
The authors explain that the increase in heatwave-led CDHEs is related to rising global temperatures, but that this does not tell the whole story.
In the earlier 22-year period of 1980-2001, the study finds that the spatial extent of heatwave-led CDHEs rises by 1.6% per 1C of global temperature rise. For the more-recent period of 2022-23, this increases “nearly eightfold” to 13.1%.
The change suggests that the rapid increase in the heatwave-led CDHEs occurred after the global average temperature “surpasse[d] a certain temperature threshold”, the paper says.
This threshold is an absolute global average temperature of 14.3C, the authors estimate (based on an 11-year average), which the world passed around the year 2000.
Investigating the recent surge in heatwave-leading CDHEs further, the researchers find a “regime shift” in land-atmosphere dynamics “toward a persistently intensified state after the late 1990s”.
In other words, the way that drier soils drive higher surface temperatures, and vice versa, is becoming stronger, resulting in more heatwave-led compound events.
Daily data
The research has some advantages over other previous studies, Yeh says. For instance, the new work uses daily estimations of CDHEs, compared to monthly data used in past research. This is “important for capturing the detailed occurrence” of these events, says Yeh.
He adds that another advantage of their study is that it distinguishes the sequence of droughts and heatwaves, which allows them to “better understand the differences” in the characteristics of CDHEs.
Dr Meryem Tanarhte is a climate scientist at the University Hassan II in Morocco, and Dr Ruth Cerezo Mota is a climatologist and a researcher at the National Autonomous University of Mexico. Both scientists, who were not involved in the study, agree that the daily estimations give a clearer picture of how CDHEs are changing.
Cerezo-Mota adds that another major contribution of the study is its global focus. She tells Carbon Brief that in some regions, such as Mexico and Africa, there is a lack of studies on CDHEs:
“Not because the events do not occur, but perhaps because [these regions] do not have all the data or the expertise to do so.”
However, she notes that the reanalysis data used by the study does have limitations with how it represents rainfall in some parts of the world.
Compound impacts
The study notes that if CDHEs continue to intensify – particularly events where heatwaves are the precursors – they could drive declining crop productivity, increased wildfire frequency and severe public health crises.
These impacts could be “much more rapid and severe as global warming continues”, Yeh tells Carbon Brief.
Tanarhte notes that these events can be forecasted up to 10 days ahead in many regions. Furthermore, she says, the strongest impacts can be prevented “through preparedness and adaptation”, including through “water management for agriculture, heatwave mitigation measures and wildfire mitigation”.
The study recommends reassessing current risk management strategies for these compound events. It also suggests incorporating the sequences of drought and heatwaves into compound event analysis frameworks “to enhance climate risk management”.
Cerezo-Mota says that it is clear that the world needs to be prepared for the increased occurrence of these events. She tells Carbon Brief:
“These [risk assessments and strategies] need to be carried out at the local level to understand the complexities of each region.”
The post Heatwaves driving recent ‘surge’ in compound drought and heat extremes appeared first on Carbon Brief.
Heatwaves driving recent ‘surge’ in compound drought and heat extremes
Greenhouse Gases
DeBriefed 6 March 2026: Iran energy crisis | China climate plan | Bristol’s ‘pioneering’ wind turbine
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Energy crisis
ENERGY SPIKE: US-Israeli attacks on Iran and subsequent counterattacks across the Middle East have sent energy prices “soaring”, according to Reuters. The newswire reported that the region “accounts for just under a third of global oil production and almost a fifth of gas”. The Guardian noted that shipping traffic through the strait of Hormuz, which normally ferries 20% of the world’s oil, “all but ground to a halt”. The Financial Times reported that attacks by Iran on Middle East energy facilities – notably in Qatar – triggered the “biggest rise in gas prices since Russia’s full-scale invasion of Ukraine”.
‘RISK’ AND ‘BENEFITS’: Bloomberg reported on increases in diesel prices in Europe and the US, speculating that rising fuel costs could be “a risk for president Donald Trump”. US gas producers are “poised to benefit from the big disruption in global supply”, according to CNBC. Indian government sources told the Economic Times that Russia is prepared to “fulfil India’s energy demands”. China Daily quoted experts who said “China’s energy security remains fundamentally unshaken”, thanks to “emergency stockpiles and a wide array of import channels”.
‘ESSENTIAL’ RENEWABLES: Energy analysts said governments should cut their fossil-fuel reliance by investing in renewables, “rather than just seeking non-Gulf oil and gas suppliers”, reported Climate Home News. This message was echoed by UK business secretary Peter Kyle, who said “doubling down on renewables” was “essential” amid “regional instability”, according to the Daily Telegraph.
China’s climate plan
PEAK COAL?: China has set out its next “five-year plan” at the annual “two sessions” meeting of the National People’s Congress, including its climate strategy out to 2030, according to the Hong Kong-based South China Morning Post. The plan called for China to cut its carbon emissions per unit of gross domestic product (GDP) by 17% from 2026 to 2030, which “may allow for continued increase in emissions given the rate of GDP growth”, reported Reuters. The newswire added that the plan also had targets to reach peak coal in the next five years and replace 30m tonnes per year of coal with renewables.
ACTIVE YET PRUDENT: Bloomberg described the new plan as “cautious”, stating that it “frustrat[es] hopes for tighter policy that would drive the nation to peak carbon emissions well before president Xi Jinping’s 2030 deadline”. Carbon Brief has just published an in-depth analysis of the plan. China Daily reported that the strategy “highlights measures to promote the climate targets of peaking carbon dioxide emissions before 2030”, which China said it would work towards “actively yet prudently”.
Around the world
- EU RULES: The European Commission has proposed new “made in Europe” rules to support domestic low-carbon industries, “against fierce competition from China”, reported Agence France-Presse. Carbon Brief examined what it means for climate efforts.
- RECORD HEAT: The US National Oceanic and Atmospheric Administration has said there is a 50-60% chance that the El Niño weather pattern could return this year, amplifying the effect of global warming and potentially driving temperatures to “record highs”, according to Euronews.
- FLAGSHIP FUND: The African Development Bank’s “flagship clean energy fund” plans to more than double its financing to $2.5bn for African renewables over the next two years, reported the Associated Press.
- NO WITHDRAWAL: Vanuatu has defied US efforts to force the Pacific-island nation to drop a UN draft resolution calling on the world to implement a landmark International Court of Justice (ICJ) ruling on climate, according to the Guardian.
98
The number of nations that submitted their national reports on tackling nature loss to the UN on time – just half of the 196 countries that are part of the UN biodiversity treaty – according to analysis by Carbon Brief.
Latest climate research
- Sea levels are already “much higher than assumed” in most assessments of the threat posed by sea-level rise, due to “inadequate” modelling assumptions | Nature
- Accelerating human-caused global warming could see the Paris Agreement’s 1.5C limit crossed before 2030 | Geophysical Research Letters covered by Carbon Brief
- Future “super El Niño events” could “significantly lower” solar power generation due to a reduction in solar irradiance in key regions, such as California and east China | Communications Earth & Environment
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday,