The year 2025 has seen exceptionally dry conditions in many parts of the UK.
At the time of writing, a large area of England is officially “in drought” and hosepipe bans are in force for more than 8m households.
This follows severe drought episodes in the summers of 2022 and 2018 – which raises the question of whether these events are part of a pattern towards a drier future.
However, the intervening periods between these drought events have been associated with major floods.
There is good reason to assume this “hydrological volatility” could be linked to climate change.
Writing for Carbon Brief in 2020, we explored how climate change might be impacting UK river flooding.
Here, we revisit this theme – but ask whether global warming is driving a long-term trend towards increasing drought severity in the UK.
To do so, we draw from the findings of a 2023 Environment Agency report, a chapter of which we authored and has now been accepted for publication in a peer-reviewed journal.
Key findings include:
- Future projections indicate hydrological droughts will become more severe in the UK, especially over the months of April to September, due to hotter, drier summers.
- However, observations from the past 50 years – and longer where records allow – do not provide evidence of worsening drought.
- This apparent conflict is largely because natural climate variability can obscure underlying trends driven by climate change.
- An increasingly variable climate in the UK means planners still need to prepare for more severe droughts, as well as more floods.
The 2025 hydrological drought
Droughts are complex events that vary in duration, time of year, location and severity.
They are often categorised into different types. For example, a meteorological drought is defined by a lack of rainfall – whereas agricultural drought is a period when there is not enough water for crops to grow.
Here, we are focusing on hydrological drought, which is when a lack of rainfall results in less water in streams, lakes, rivers and reservoirs.
In particular, we look at deficits in river flow. It is through dwindling river flows that droughts have some of their greatest impacts on society and the environment.
Over March-July of this year, flows for many UK rivers were at their lowest level on record. Hosepipe bans have been introduced by water companies, while the Environment Agency has imposed restrictions on extracting water from rivers and warned of widespread environmental impacts, such as fish die-offs and algal blooms in rivers, streams and lakes.
The map below shows how a significant number of rivers in the UK this spring saw exceptionally low flows (marked by a dark red circle) or notably low flows (marked by an orange circle) compared to the 1991-2020 average. This includes many rivers in northern parts of Great Britain – which is typically wetter the south-east.
The graphs on the right, meanwhile, show how flows in the River Derwent and the River Wye (black line) in 2025 have been at equivalent levels, or lower, than in major past droughts (red, green and orange lines). This includes the record-breaking drought of 1976 (orange line), often used as a benchmark.
How is climate change going to affect droughts in the UK?
Globally, climate change causes an intensification of the hydrological cycle. This means that both wet and dry extremes – floods and droughts – are likely to become more frequent and severe.
One way of understanding the impact of climate change on hydrological drought is to use rainfall and temperature projections from climate models to drive hydrological models that simulate how the flow of water through river catchments could change in the future.
There are numerous studies that provide such projections of UK drought. (A summary of these can be found in the chapter on modelling in the 2023 Environment Agency report, linked above.)
Across these studies, river flow models generally show that, in the future, the UK should expect lower summer river flows, increasing drought severity and decreasing minimum flows – in other words, the lowest flows in each year will get lower.
The graphs below show projections of changing low flows for a selection of UK rivers from the 1980s to the 2080s over consecutive 30-year moving averages (1983-2012, 1984-2013 and so on, through to 2050-79).
These projections are based on the “enhanced future flows and groundwater” (Eflag) dataset, which provides simulated river flows for 200 catchments around the UK, using four river flow models. These are driven by the “regional” projections from the Met Office’s UK Climate Projections 2018 (UKCP18), a 12-member climate model “ensemble” which uses the very-high-emission RCP8.5 scenario.
(For more on why this regional data is only available under this pathway, read Carbon Brief’s in-depth Q&A on UKCP18.)
The multiple lines on each plot – which indicate different projections for low flows – show the uncertainties arising from the different climate model runs and river flow models used.
The charts reveal that, across all rivers and different future trajectories, the trend points in the same direction – towards diminishing minimum flows. This suggests a drier future across the UK, most notably in the summer.
Past trends in drought
Given these projections, we would expect to see a similar trend of decreasing minimum flows emerging in observational data over the last few decades.
However, our research concludes that there is little compelling evidence for any evidence of a widespread worsening of UK droughts over the last half century – yet.
The maps below show how river flows have changed since 1965 across the UK for very low (Q95), medium-low (Q70) and median (Q50) flows.
For much of the north and west of the UK, the lowest flows in each year have, in fact, increased since 1965 (blue triangles). In the south and east of the country, there are decreases (inverted red triangles), but it is a mixed picture. Overall, the number of statistically significant trends is modest.
But, while these river flow records span more than 50 years, this is still a relatively short timeframe.
As a result, we also explored much longer records, including “reconstructed” river flows, which stretch back to 1890. Here, too, we find there is no consistent trend towards worsening drought over these long periods.
In fact, our research shows how trends in the last 50 years are often unrepresentative of longer-term changes. Some of the apparent decreasing trends from the maps above disappear when a longer view is taken.
Mismatch between past trends and future projections
There is a clear contradiction between future projections and past trends. We do not yet see much evidence of the drier future that climate models project.
However, this apparent contradiction is unsurprising once uncertainties inherent in both future projections and historical observations are considered.
Future projections are highly uncertain and span a wide range of possibilities – as shown by the multiple lines in the Eflag graphs above.
Caution is needed in interpreting trends in observations, too. While 50 years seems a reasonably long period, trends can be influenced by variability associated with natural atmospheric and oceanic circulation patterns.
The trends towards increasing river flows in the north and west are consistent with changes in the North Atlantic Oscillation (NAO) – the atmospheric pressure system that influences the UK’s weather on year-to-year and decade-to-decade timescales.
There is a growing list of drivers of drought variability, including the El Niño-Southern Oscillation (ENSO) and the role of the influx of freshwater into the North Atlantic due to the melting of the Greenland ice sheet.
In a recent paper, we highlighted that long-term trends in low river flows for many UK catchments may not be detectable for decades due to being obscured by natural climate variability.
This is shown by the plot below, which illustrates how projected trends of very low river flows over the 21st century (red line) contrasts with the estimated range of historical river flow variability (dashed lines). (The grey shading shows the range of different climate models.)
It shows that for some catchments – for example, the Lambourn River in south-east England – significant trends do not emerge until the 2050s.
Part of the mismatch between historical observations and climate projections for UK summer is due to a run of wet summers from the late 2000s onwards. This climate variability has ‘masked’ an underlying trend that could eventually emerge and bring a more worrisome consistency with the projections of climate models.
That this masking has often entailed living with an excess of water, in the form of widespread, damaging flooding, only highlights the challenges water managers face.
A drier and wetter future
Further research is required into how different types of hydrological drought will evolve.
We are confident we will see more droughts in April-September, typically associated with heatwaves, as in 2025, 2022 and 2018. This is because warming temperatures – which, unlike rainfall trends, are certain – will exacerbate droughts.
The increased likelihood of hot, dry summers also means more rapid-onset “flash droughts”, which have impacts on soil moisture as well as river flows.
As such, the droughts of recent years should be interpreted as a warning that hotter temperatures will worsen drought impacts.
However, we are much less confident that we will see more long, multi-annual droughts driven by dry winters that fail to replenish reservoirs and aquifers, such as those seen in 1988-93, 2005-06 and 2010-12. This is because climate models generally predict wetter winters for the UK. (These multi-annual droughts have, historically, posed some of the greatest challenges to water management.)
Nevertheless, climate variability means that even if winters get wetter, there will always be runs of dry years. This is a cause for concern, as the greatest problems occur when wet winters combine with dry summers. (It was the dry winter of 1975-76 which made the 1976 drought so severe).
Our finding that it is difficult to confirm whether droughts are, overall, becoming more severe offers little comfort to water managers preparing for the future.
Our research offers a number of recommendations for water planners trying to navigate this complexity. This includes using large climate model “ensembles” to test the resilience of water supply systems to different types of droughts. Although model projections are uncertain, they provide a way to assess the UK’s vulnerability to a range of future outcomes.
Furthermore, the hydrological volatility of the recent past indicates the importance of preparing for both a drier and wetter future in the UK.
The UK is known for its variable weather, but it will have a future climate that is even more variable and extreme.
The post Guest post: Is climate change making UK droughts worse? appeared first on Carbon Brief.
SYDNEY, Thursday 30 October 2026 — In response to reports that the Albanese government is set to introduce draft legislation this year that would seek to ban data centres in Australia’s suburbs, Joe Rafalowicz, Head of Climate and Energy at Greenpeace Australia Pacific, said:
“These reports are a testament to the growing community opposition to these completely inappropriate AI factories that have sprung up across our suburbs, and Big Tech corporations should take heed — the data centre build-out must not happen without the endorsement of the Australian people.
“But the government can’t simply ship this problem out to regional Australia without addressing the fundamental issues with this extractive new industry.
“We’re already seeing a trend of AI data centre proposals moving to the regions, in areas that are more water-scarce, more environmentally sensitive, and next to sources of fracked and coal seam gas to support their massive BYO gas-fired power plans — a pattern we’ve seen play out in the United States.
“From the Beetaloo Basin in the NT to the Western Downs in Qld, we’re seeing a wave of AI data centre proposals that would see new gas fast-tracked to support their massive energy demand, and threaten to completely derail Australia’s energy transition.
“Just as suburban Australians are asking, “what for?”, regional communities like Berry Springs and Dalby do not want dirty data centres setting up shop with absolutely no benefit to their communities. Greenpeace is calling for a moratorium on AI data centre developments until strict and enforceable safeguards are in place to protect our climate and our communities.”
-ENDS-
Media contact
Kate O’Callaghan on +61 406 231 892 or kate.ocallaghan@greenpeace.org
AI data centre ban in suburbs would not address fundamental issues: Greenpeace
In the thick of the COP29 climate summit in Azerbaijan in 2024, the UN climate talks were rattled by what can only be described as a major PR disaster. The BBC, Reuters and The Guardian all carried headlines, attributed to leading climate policy experts, that the COPs were “no longer fit for purpose”.
The articles outlined a series of reforms called for in an open letter signed by 22 eminent scientists and politicians, including a former UN secretary-general and previous UN climate chief, with a further 150 lending their support. The headlines shook confidence in the COP process, just as governments were wrestling over a new climate finance goal.
The Club of Rome – which handled the media relations for the letter – hurried to say that its “constructive, supportive ideas” had been “misinterpreted”. Negotiators kept calm(ish) and carried on, in the end landing the finance goal after some high-stakes drama on the final day.
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Early speakers’ list suggests few powerful leaders will attend COP31
Just 77 heads of state or government are scheduled to address the COP31 climate summit in Antalya, a third less than the COP28 peak -
Africa wants adaptation finance on COP31 agenda, raising risk of a fight
The African Group wants dedicated space on tripling adaptation finance, the Green Climate Fund and trade, setting up a possible clash
To my surprise, when I went back this week to read the letter again, I could not find the offending line about the COPs not being fit for purpose. The Club of Rome has yet to respond to my query about its disappearance.
Whatever happened to the wording, that sentiment has been widely shared. COPs have ballooned in size while the importance of their outcomes seems to have diminished since the 2015 Paris Agreement (with the exception of the 2023 COP in Dubai where countries agreed to transition away from fossil fuels in energy systems).
The same on the surface
Two years on from those painful headlines in Baku, has anything changed for the better? You might be forgiven for thinking not. Official decisions are still made by consensus rather than the majority voting some have called for to stop blockers.
Tens of thousands of officials, activists and business execs still scurry around the halls to an ever-growing list of side events, roundtables and dialogues, while deals still come down to rows, all-nighters and jargon-filled texts adopted to rounds of applause.
But it would not be true to say that COPs have completely failed to respond to the very real need to translate the words of the Paris Agreement into action in the outside world.
Global warming is projected to be around 1.3C lower this century than it would have been if the world had not committed to tackle the climate crisis under that accord. Developing countries have a valued space at COPs in which their voices have equal weight in decision-making, unlike in many other international fora. And most importantly, perhaps, there has been a subtle shift, tipping the balance away from negotiating towards doing.
Brazil branded last year’s summit in Belém as the “COP of Implementation”, corralling the sprawling Action Agenda into six axes. This was a bid to impose some structure on the mushrooming efforts between governments, UN agencies, cities, businesses and civil society to set targets and spur faster results on their pet issues, from methane emissions to health and adaptation in conflict zones. COP30 alone saw the launch of 120 “plans to accelerate solutions”.
COP30 roadmaps off the cuff
Meanwhile, as the formal negotiations drew to a close, it was clear that consensus decision-making was evolving into something a little more improvised.
With only around half of all countries on board with the idea of a roadmap to transition away from fossil fuels, COP30 President André Corrêa do Lago announced his team would put one together over the coming year, along with another on how to meet a global goal to halt deforestation by 2030. Those roadmaps will be launched next week, presented and discussed at COP31, though it’s still unclear whether or how they’ll be incorporated into the formal negotiating agenda.
Some leading policy-makers don’t think that matters too much. Speaking to journalists before the Antalya summit, COP30 CEO Ana Toni and Dutch climate minister Stientje van Veldhoven said “coalitions of the willing” can move ahead without needing consensus from the COPs. This, they said, was evident this year at the first global conference on TAFF, co-chaired by van Veldhoven and attended by 60 countries.
“Consensus or no-consensus in the general COP doesn’t make a difference for the choices I have to make in my country to get my country to phase out fossil fuels,” said the Dutch minister. The Netherlands recently became one of the first to publish a national TAFF plan.
COP31 banks on flagship voluntary initiatives
This thinking has permeated the management and expected outcomes of this year’s COP too. Earlier this year, Türkiye, supported by international energy agencies, floated the idea of a voluntary goal to boost electrification to 35% of the world’s final energy consumption by 2035 – and this is now being touted as one of the main results to be expected from Antalya.
Türkiye is also championing a pledge on AI and climate, while co-host Australia is pushing to ease access to climate finance for least developed countries and small island states.
COP31 presidency announces AI pledge as UN climate chief says Big Tech ‘on thin ice’
None of these needs consensus. But with a political cover decision already in the works, as trailed by the COP presidents, they – and perhaps the fossil fuel roadmap – may find a home in the official text if language acceptable to most can be found, giving them them additional weight.
UNFCCC reform process in the shadows
Formal reform is underway too, if quietly. UN climate chief Simon Stiell is leading a review informed by ongoing consultations with a group of 15 well-respected climate policy experts, three of whom signed the open letter in 2024.
Among them is leading Swedish climate and sustainability scientist Johan Rockström who has strong ideas about how to make COPs function better, including a switch to majority voting. He told the same press briefing nothing stands in the way of this, because the rules of procedure for making decisions at COPs have never been formally agreed.
Still, to get away from the default setting of consensus would require agreement on a new system that may be impossible to achieve given the rise in bullying tactics by fossil fuel heavyweights.
Comment: The UN climate process was built for negotiation – now it must support implementation
The deliberations with the high-level policy gurus, as reflected in a summary of June’s session in Bonn, largely echo what’s already happening organically, calling for stronger partnerships and accountability both in and between the Action Agenda and negotiations. It doesn’t mention voting.
A general overview of the reform exercise says that “improving and optimizing the [UN climate] process over the medium to long term… will be critical to fostering trust, enhancing collaboration, and catalyzing increased ambition”.
In the short term, don’t hold your breath for anything concrete on reform at COP31 but watch for signs in what ends up dominating the headlines from Türkiye.
The post Editor’s Desk: COP reform is happening quietly, behind the headlines appeared first on Climate Home News.
Editor’s Desk: COP reform is happening quietly, behind the headlines