This week, the international court of justice (ICJ) opened two weeks of hearings on states’ climate-related legal obligations – and the consequences, if “significant harm” is caused.
The case stems from a unanimous UN general assembly (UNGA) request for an “advisory opinion” from the ICJ.
It is taking place against a backdrop of rapidly escalating climate impacts. Emissions continue to rise, rather than falling rapidly, as needed to avoid dangerous levels of global warming.
It is the ICJ’s largest ever case, with more than 100 countries and international organisations making interventions, deploying a wide variety of legal arguments.
Ralph Regenvanu, climate envoy for Vanuatu, which led the campaign for the ICJ hearings, said in his opening address: “[T]his may well be the most consequential case in the history of humanity.”
Below, Carbon Brief interviews leading international law scholar Prof Philippe Sands – who drafted the pleadings for Mauritius, but is speaking here in a personal capacity – to find out more about the legal issues at stake and the wider significance of the ICJ case.
- On the significance of the case: “It’s the first time the ICJ has been called upon to address legal issues relating to climate change.”
- On the key legal arguments: “There’s just a huge number of issues that are coming up.”
- On climate obligations under the UN: “Will the court open the door to the situation that the 1992 [UN climate] convention … [is] not the be all and end all?”
- On where outcomes could come from: “Essentially, it’s the whole of international law!”
- On the responsibility of states: “The question at the beating heart of this case, really, is the consequences of emissions over time.”
- On historical emissions: “The big issue is, are you liable for the continuing consequences of your past emissions?”
- On applying international law: “When drafting the climate treaty regime, [did] states…exclude the application of general international law?”
- On expectations for the case: “What I’m interested in, really, is an advisory opinion that is capable of having hard, practical application.”
- On the state of the science: “A procedure in which the judges hear privately from any person…is unusual. It’s unorthodox.”
- On the significance of the submissions: “The oral phase is very important, because it basically concentrates the issues down to the most significant and narrow set of issues.”
- On the question of the UN or wider law: “It’s a tough situation for the judges.”
Carbon Brief: Would you be able to start by just situating this case in its wider legal context and explaining why it could be so consequential?
Philippe Sands: Well, it’s the first time the international court of justice has been called upon to address legal issues relating to climate change. The ICJ is the principal judicial organ of the United Nations and, although the advisory opinion that it hands down will not be binding on states, it is binding on all UN bodies. The determinations that the court makes will have consequences that go very far and that will have a particular authority, in legal and political terms. Of course, everything turns on what the court actually says.
CB: Would you be able to summarise the key legal arguments that are being fought over in this case?
PS: No! I mean, there’s just a huge number of issues that are coming up. But, essentially, the court has been asked two questions by the UN General Assembly – the first time, I believe, that a request from the General Assembly has been consensual, with no objections. The two questions are, firstly, what are the obligations for states under international law to protect the climate system? And, secondly, what are the legal consequences under these obligations, where, by their acts and emissions, [states] cause significant harm to the climate system? So, there are two distinct questions – and about 100 states and international organisations of various kinds have made submissions on the vast range of issues that are raised by these two questions. The questions are very, very broad and that signals to me that the court’s response may be quite general. But, for me, the crucial issues are, firstly, what the court says about the state of the science: is it established, or is there any room for doubt? Secondly, what are the obligations of states having regard to the clarity of the science? Thirdly, are there legal obligations on states in relation to the climate system that exist and arise outside of the treaty regime – the 1992 [UN Framework] convention [on climate change], the Kyoto Protocol, the Paris Agreement and so on and so forth. And, related to that, fourthly – this is the most intense, legally interesting aspect – what are the responsibilities of states for historic emissions under general international law? And, in particular, are the biggest contributors liable under international law to make good any damages that may arise from their historic actions? But, I mean, there’s just such a vast array of questions that are addressed, it’s impossible to summarise briefly.
CB: This is the challenge I found when I was trying to write questions!
PS: To be honest, the questions [put by the UN General Assembly] are rather general, so I have concerns about the burden that has been imposed on the court. My general approach has been that, with advisory opinions, the best questions are those which require a yes or no answer. But the moment you have questions of such generality, you impose on the 15 judges an especially onerous burden, because the questions are open to interpretation.
CB: Some countries are arguing, effectively, that states’ climate obligations start and finish with the UN climate regime, as you’ve already mentioned.
PS: Exactly. Well, that’s a central aspect of what’s coming up. Will the court open the door to the situation that the 1992 [UN climate] convention and the subsequent agreements [Kyoto, Paris] are not the be all and end all, and that the rules of general international law [also] apply? And, if so, what are those rules? And what are the consequences of breaching those rules? Some states say there can’t be any liability under general international law because the whole matter is governed by the treaty regime. Other states say that’s not right, that, although the treaty regime is a distinct “lex specialis” – a specialised area of law – that does not preclude the application of the general principles of international law. So that may be a really interesting issue for the court to determine.
CB: Could you say a bit more about the other areas of international law, where obligations could come from, whether it’s human rights, or customary law, or whatever it might be?
PS: The difficulty, if you look at the first part of the question [put to the court]…the drafters of the question invite the court to have regard to the Charter of the United Nations, the Covenant on Civil and Political Rights, the Covenant on Economic and Social Rights, the Framework Convention on Climate Change, the Paris Agreement, the UN Convention on the Law of the Sea, the duty of due diligence, human rights law, the principle of prevention, and the duty to protect and preserve the marine environment. That is a vast array of international legal obligations and it’s not exhaustive. It says, having particular regard to, so, essentially, it’s the whole of international law! So the court is being asked to address the application of the whole of international law to the issue of climate change and, in particular, issues of legal consequences, and in particular, the issues of state responsibility. So, it’s vast, vast.
CB: Another set of arguments that I’ve seen…is around the idea of the “responsibility of states for internationally wrongful acts”, which might lead to a requirement for cessation of the acts and reparation of the harm done. Can you just say a bit more about what that idea means and where it comes from?
PS: There’s an area of international law called the law of state responsibility. That law of state responsibility says that when you have committed a wrongful act and violated a rule of international law, you are liable for all of the consequences. That rule has not been incorporated, as such, or at all, into the treaty regime [on climate change]. So, essentially, by raising those issues, there are a number of legal issues that arise – but there are two of particular interest. Firstly, in relation to damage that is caused by climate change, are those states most responsible, liable for the consequences of that damage in, let us say, for example, in financial terms? And, secondly – and this relates to something called the principle of “common but differentiated responsibility” – does the fact that certain states have historic emissions going back 200 years mean that their entitlement to the remaining “carbon budget” is reduced. So, the question, I think, at the beating heart of this case, really, is the consequences of emissions over time, looking back and looking forward. That’s one aspect the court may have at the forefront of its mind.
CB: Historical greenhouse gas emissions, but also the rights of future generations, have both come up quite a lot in some of the submissions. Can you just say a bit more about the legal arguments around these?
PS: The big issue is: are you liable for the continuing consequences of your past emissions? And does the nature and extent of your past emissions affect your ability to generate emissions in the future? Those are really the two issues and the treaty regime does not, as such, explicitly address [them]. The practicalities are that islands are disappearing with sea level rise. Are historic polluters of greenhouse gases responsible for the consequences of those disappearances? Or, if states are required to build sea walls to protect themselves, can they bring a case against the biggest polluters for the consequences of sea level rise? That’s the kind of complex issue the court may have in the back of its mind, because that’s essentially what’s being asked.
CB: In terms of how they will decide whether these other potential areas of law could give rise to obligations on states – and, therefore, potentially further consequences – how are they going to decide? To decide whether those [areas of law] do apply, or whether it is only the UN climate regime that gives rise to obligations.
PS: They are going to have to address whether, when drafting the climate treaty regime, states intended to, or did as a necessary consequence, exclude the application of general international law. That is an issue that they will do by looking at the climate regime and determining whether, by adopting it, there was an intention to exclude the application of general international law. So, that is a classical job for lawyers, for judges: to interpret the law, to interpret what the drafters of the treaty regime have done and what they intended, and to then form a view in applying the general rules of international law, whether a space is left which allows those general rules to apply. That’s classically what international judges will do.
CB: You’ve already said a little bit about this, but what would your expectations be for this advisory opinion, which I gather is expected next year?
PS: Normally, it takes six months from after they’ve done the hearings for an advisory opinion to come up. I don’t really have any expectations. There’s been a previous advisory opinion in relation to the Law of the Sea proceedings. The Tribunal for the Law of the Sea came up with an advisory opinion which, in a sense, was rather general. What I’m interested in, really, is an advisory opinion that is capable of having hard, practical application, as happened, for example, in the advisory opinion on the Chagos Archipelago, where the court was asked two questions, essentially, “yes/no” questions, and the court gave a very clear advisory opinion, which has had significant political and legal consequences. The difficulty with asking very general questions is you get very general answers, and very general answers are less easily capable of practical application. So, the best-case scenario for me, is that the court comes up with an advisory opinion of sufficient clarity on the facts, which is basically the state of the science and on the applicable legal principles, which then allows other courts and, in particular, national courts, to take the advisory opinion, in interpreting and applying domestic law, which is, ultimately, going to be where the rubber hits the road. So my expectations turn on the nature and generality of the opinion that the court is able to give. But where the questions posed are so general, I would be concerned that the answers may also be rather general and that limits my expectations.
CB: You mentioned the state of the science as being very important. We know that the court met with a delegation of IPCC [Intergovernmental Panel on Climate Change] authors and I gather there’s some sort of question mark about the procedure used to do that?
PS: The normal process is that if scientists are going to provide information to the judges, it would be in the form of submissions made in writing, or in open court, publicly and transparently. A procedure in which the judges hear privately from any person, however authoritative – and the IPCC is authoritative – is unusual. It’s unorthodox. It does raise questions. We don’t know who attended. We don’t know what they said. We don’t know what the exchanges were with the judges. I have to assume that it was done by the judges, at their request, as a way of informing themselves on the state of science, which is understandable. But the more usual way for this to happen would be, as I said, in written submissions made to the court and in open submissions made already in the courtroom. So it is unusual.
CB: You mentioned already, there’s more than 100 submissions from countries and international organisations. And we’ve obviously got these two weeks of hearings, with some of those same entities making oral statements. How significant are those submissions in terms of shaping the advisory opinion of the court?
PS: My experience before the court, having been involved in a number of cases involving advisory opinions and contentious cases, is that the written pleadings are very important in setting out the generality of the arguments and the totality of the arguments. And, essentially, what you see is a narrowing down. There are essentially three rounds. The first round is the first written statement of the participating states and international organisations. Then they have a second written round, which tends to narrow down the issues and be responsive to the first round of others. And then you’ve got the oral arguments, which are limited, of course, to half an hour for each participant. And so it’s a real narrowing down and homing in. Essentially, what the oral arguments are doing is signaling to the judges what the states participating think are the most significant issues. That’s why the oral phase is very important, because it basically concentrates the issues down to the most significant and narrow set of issues. And so it gives the judges a sense of what states think are the most important issues to be addressed. Secondly, it provides states with an opportunity to hear what responses each state has made to the written submissions of other states. So the oral phase is significant.
CB: If you were going to make a bet, which way would you say the court would go on that key question of whether it’s just the [UN] climate regime that gives rise to obligations [on states], or whether there could be obligations from other parts of the law?
PS: I think the court will proceed very carefully. I don’t think it will want to close the door to the application of other rules of international law. Rather, as the International Tribunal for the Law of the Sea did, which opened the door to the application of the Law of the Sea Convention to the issue of climate change – and opened it quite widely. I don’t know precisely where the court will go. But I would be surprised if they said general international law does not govern issues related to climate change.
The interesting area to read, in what they say, will be the relationship between the general rules and the treaty rules. I mean, the broader issue here is that, essentially, the legislative system has broken down. The states have been unable to legislate effectively and efficiently to address the issues related to climate change. And so what has happened is that a group of states have essentially gone to the General Assembly and said: “The legislative system is broken down. Let’s now ask the judges to step in and tell us what the applicable principles and rules are.” The difficulty that that poses for the judges, who will be conscious that the legislative system has not delivered, is that it’s not the function of judges to legislate. The function of judges is limited to interpreting the law and applying it to the facts, to identify the existence of rules and then applying them to the facts. So I would have thought the instinct of the judges will be to do something, but not to want to overstep the proper boundaries on the judicial function. And that’s a difficult challenge for the judges that they find themselves in.
[It is] a very delicate and difficult situation in the face of, on the one hand, the urgent need for action, and, on the other hand, the failure of states, essentially, to deal with the situation and act as the scientists tell us is needed. I don’t know whether you’ve been through all the different pleadings. I drafted the pleadings for Mauritius – I’m speaking here in a personal capacity. Mauritius decided not to participate in the oral hearings, but you can go on to the Mauritius statement and, if you look at the second Mauritius statement filed in August, you’ll find attached to it as an annex, a report by Prof James Hansen, one of the world’s leading scientists. And that really indicates, with crystal clarity, the urgency of the situation. He’s one of the world’s leading scientists on this issue and that’s the kind of submission that could concentrate the minds of the judges and, I think, impel them to want to go as far as they can. But they’ll be acutely conscious of the limits of judicial function. And, of course, you know, some countries like the UK are basically saying, butt out, leave it to the treaty negotiators, leave it to the treaty system. And the US has said essentially the same thing yesterday. So, it’s a tough situation for the judges.
An abridged version of this interview was published in DeBriefed, Carbon Brief’s weekly email newsletter. Sign up for free.
The interview was conducted by Simon Evans via phone on 5 December 2024.
The post Interview: Prof Philippe Sands on UN court’s landmark climate-change hearing appeared first on Carbon Brief.
Interview: Prof Philippe Sands on UN court’s landmark climate-change hearing
Permitting reform: A major key to cutting climate pollution
By Dana Nuccitelli, CCL Research Coordinator
Permitting reform has emerged as the biggest and most important clean energy and climate policy area in the 119th Congress (2025-2026).
To make sure every CCL volunteer understands the opportunities and challenges ahead, CCL Vice President of Government Affairs Jennifer Tyler and I recently provided two trainings about the basics of permitting reform and understanding the permitting reform landscape.
These first introductory trainings set the stage for the rest of an ongoing series, which will delve into the details of several key permitting reform topics that CCL is engaging on. Read on for a recap of the first two trainings and a preview of coming attractions.
Permitting reform basics
Before diving into the permitting reform deep end, we need to first understand the fundamentals of the topic: what is “permitting”? What problems are we trying to solve with permitting reform? Why is it a key climate solution?
In short, a permit is a legal authorization issued by a government agency (federal and/or state and/or local) that allows a specific activity or project to proceed under certain defined conditions. The permitting process ensures that public health, safety, and the environment are protected during the construction and operation of the project.
But the permitting process can take a long time, and in some cases it’s taking so long that it’s unduly slowing down the clean energy transition. “Permitting reform” seeks to make the process more efficient while still ensuring that public health, safety, and the environment are protected.
There are a lot of factors involved in the permitting reform process, including environmental laws, limitations on lawsuits, and measures to expedite the building of electrical transmission lines that are key for expanding the capacity of America’s aging electrical grid in order to allow us to connect more clean energy and meet our energy affordability and security and climate needs.
But if we can succeed in passing a good, comprehensive permitting reform package through Congress, it could unlock enough climate pollution reductions to offset what we lost from this year’s rollback of the Inflation Reduction Act’s clean energy investments. Permitting reform is the big climate policy in the current session of Congress.
Understanding the permitting reform landscape
In the second training of this series, we sought to understand the players and the politics in the permitting reform space, learn about the challenges involved, and explore CCL’s framework and approach for weighing in on this policy topic.
Permitting reform has split some traditional alliances along two differing theories about how to best address climate change. Some groups with a theory of change relying on using permitting and lawsuits to slow and stop fossil fuel infrastructure are least likely to be supportive of a permitting reform effort. Groups like CCL that recognize the importance of quickly building lots of clean, affordable energy infrastructure are more supportive of permitting reform measures.
The subject has created some strange bedfellows, because clean energy and fossil fuel companies and organizations all want efficient permitting for their projects, and hence all tend to support permitting reform. For CCL, the key question is whether a comprehensive permitting reform package will be a net benefit to clean energy or the climate — and that’s what we’re working toward.
The two major political parties also have different priorities when it comes to permitting reform. Republicans tend to view it through a lens of reducing government red tape, ensuring that laws and regulations are only used for their intended purpose, and achieving energy affordability and security. Democrats prioritize building clean energy faster to slow climate change, addressing energy affordability, and protecting legacy environmental laws and community engagement.
As we discussed in the training, there are a number of key concepts that will require compromise from both sides of the aisle in order to reach a durable bipartisan permitting reform agreement. We’ll delve into the details of these in these upcoming trainings:
The Challenge of Energy Affordability and Security
First, with support from CCL’s Electrification Action Team, on February 5 I’ll examine what’s behind rising electricity rates and energy insecurity in the U.S. and how we can solve these problems. Electrification is a key climate solution in the transition to clean energy sources. But electricity rates are rising fast and face surging demand from artificial intelligence data centers. Permitting reform can play a key role in addressing these challenges.
Transmission Reform and Key Messages
Insufficient electrical transmission capacity is acting as a bottleneck slowing down the deployment of new clean energy sources in the U.S. Reforming cumbersome transmission permitting processes could unlock billions of tons of avoided climate pollution while improving America’s energy security and affordability. In this training on March 5, Jenn and I will dive into the details of the key clean energy and climate solution that is transmission reform, and the key messages to use when lobbying our members of Congress.
Clean energy projects often encounter long, complex permitting steps that slow construction and raise costs. Practical permitting reforms can help ensure that good projects move forward faster while upholding environmental and community protections. In this training on March 19, Jenn and I will examine permitting reforms to build energy infrastructure faster, some associated tensions and compromises that they may involve, and key messages for congressional offices.
Presidents from both political parties have taken steps to interfere with the permitting of certain types of energy infrastructure that they oppose. These executive actions create uncertainty that inhibits the development of new energy sources in the United States. For this reason, ensuring fair permitting certainty is a key aspect of permitting reform that enjoys bipartisan support. In this training on April 2, Jenn and I will discuss how Congress can ensure certainty in a permitting reform package, and key messages for congressional offices.
Community Engagement and Key Messages
It’s important for energy project developers to engage local communities in order to address any local concerns and adverse impacts that may arise from new infrastructure projects. But it’s also important to strike a careful balance such that community input can be heard and addressed in a timely manner without excessively slowing new clean energy project timelines. In this training on May 7, Jenn and I will examine how community engagement may be addressed in the permitting reform process, and key messages for congressional offices.
We look forward to nerding out with you in these upcoming advanced and important permitting reform trainings! 
Want to take action now? Use our online action tool to call Congress and encourage them to work together on comprehensive permitting reform.
The post Permitting reform: A major key to cutting climate pollution appeared first on Citizens' Climate Lobby.
Greenhouse Gases
DeBriefed 30 January 2026: Fire and ice; US formally exits Paris; Climate image faux pas
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
This week
Fire and ice
OZ HEAT: The ongoing heatwave in Australia reached record-high temperatures of almost 50C earlier this week, while authorities “urged caution as three forest fires burned out of control”, reported the Associated Press. Bloomberg said the Australian Open tennis tournament “rescheduled matches and activated extreme-heat protocols”. The Guardian reported that “the climate crisis has increased the frequency and severity of extreme weather events, including heatwaves and bushfires”.
WINTER STORM: Meanwhile, a severe winter storm swept across the south and east of the US and parts of Canada, causing “mass power outages and the cancellation of thousands of flights”, reported the Financial Times. More than 870,000 people across the country were without power and at least seven people died, according to BBC News.
COLD QUESTIONED: As the storm approached, climate-sceptic US president Donald Trump took to social media to ask facetiously: “Whatever happened to global warming???”, according to the Associated Press. There is currently significant debate among scientists about whether human-caused climate change is driving record cold extremes, as Carbon Brief has previously explained.
Around the world
- US EXIT: The US has formally left the Paris Agreement for the second time, one year after Trump announced the intention to exit, according to the Guardian. The New York Times reported that the US is “the only country in the world to abandon the international commitment to slow global warming”.
- WEAK PROPOSAL: Trump officials have delayed the repeal of the “endangerment finding” – a legal opinion that underpins federal climate rules in the US – due to “concerns the proposal is too weak to withstand a court challenge”, according to the Washington Post.
- DISCRIMINATION: A court in the Hague has ruled that the Dutch government “discriminated against people in one of its most vulnerable territories” by not helping them to adapt to climate change, reported the Guardian. The court ordered the Dutch government to set binding targets within 18 months to cut greenhouse gas emissions in line with the Paris Agreement, according to the Associated Press.
- WIND PACT: 10 European countries have agreed a “landmark pact” to “accelerate the rollout of offshore windfarms in the 2030s and build a power grid in the North Sea”, according to the Guardian.
- TRADE DEAL: India and the EU have agreed on the “mother of all trade deals”, which will save up to €4bn in import duty, reported the Hindustan Times. Reuters quoted EU officials saying that the landmark trade deal “will not trigger any changes” to the bloc’s carbon border adjustment mechanism.
- ‘TWO-TIER SYSTEM’: COP30 president André Corrêa do Lago believes that global cooperation should move to a “two-speed system, where new coalitions lead fast, practical action alongside the slower, consensus-based decision-making of the UN process”, according to a letter published on Tuesday, reported Climate Home News.
$2.3tn
The amount invested in “green tech” globally in 2025, marking a new record high, according to Bloomberg.
Latest climate research
- Including carbon emissions from permafrost thaw and fires reduces the remaining carbon budget for limiting warming to 1.5C by 25% | Communications Earth & Environment
- The global population exposed to extreme heat conditions is projected to nearly double if temperatures reach 2C | Nature Sustainability
- Polar bears in Svalbard – the fastest-warming region on Earth – are in better condition than they were a generation ago, as melting sea ice makes seal pups easier to reach | Scientific Reports
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
Captured
Sales of electric vehicles (EVs) overtook standard petrol cars in the EU for the first time in December 2025, according to new figures released by the European Automobile Manufacturers’ Association (ACEA) and covered by Carbon Brief. Registrations of “pure” battery EVs reached 217,898 – up 51% year-on-year from December 2024. Meanwhile, sales of standard petrol cars in the bloc fell 19% year-on-year, from 267,834 in December 2024 to 216,492 in December 2025, according to the analysis.
Spotlight
Looking at climate visuals
Carbon Brief’s Ayesha Tandon recently chaired a panel discussion at the launch of a new book focused on the impact of images used by the media to depict climate change.
When asked to describe an image that represents climate change, many people think of polar bears on melting ice or devastating droughts.
But do these common images – often repeated in the media – risk making climate change feel like a far-away problem from people in the global north? And could they perpetuate harmful stereotypes?
These are some of the questions addressed in a new book by Prof Saffron O’Neill, who researches the visual communication of climate change at the University of Exeter.
“The Visual Life of Climate Change” examines the impact of common images used to depict climate change – and how the use of different visuals might help to effect change.
At a launch event for her book in London, a panel of experts – moderated by Carbon Brief’s Ayesha Tandon – discussed some of the takeaways from the book and the “dos and don’ts” of climate imagery.
Power of an image
“This book is about what kind of work images are doing in the world, who has the power and whose voices are being marginalised,” O’Neill told the gathering of journalists and scientists assembled at the Frontline Club in central London for the launch event.
O’Neill opened by presenting a series of climate imagery case studies from her book. This included several examples of images that could be viewed as “disempowering”.
For example, to visualise climate change in small island nations, such as Tuvalu or Fiji, O’Neill said that photographers often “fly in” to capture images of “small children being vulnerable”. She lamented that this narrative “misses the stories about countries like Tuvalu that are really international leaders in climate policy”.
Similarly, images of power-plant smoke stacks, often used in online climate media articles, almost always omit the people that live alongside them, “breathing their pollution”, she said.
During the panel discussion that followed, panellist Dr James Painter – a research associate at the Reuters Institute for the Study of Journalism and senior teaching associate at the University of Oxford’s Environmental Change Institute – highlighted his work on heatwave imagery in the media.
Painter said that “the UK was egregious for its ‘fun in the sun’ imagery” during dangerous heatwaves.
He highlighted a series of images in the Daily Mail in July 2019 depicting people enjoying themselves on beaches or in fountains during an intense heatwave – even as the text of the piece spoke to the negative health impacts of the heatwave.
In contrast, he said his analysis of Indian media revealed “not one single image of ‘fun in the sun’”.
Meanwhile, climate journalist Katherine Dunn asked: “Are we still using and abusing the polar bear?”. O’Neill suggested that polar bear images “are distant in time and space to many people”, but can still be “super engaging” to others – for example, younger audiences.
Panellist Dr Rebecca Swift – senior vice president of creative at Getty images – identified AI-generated images as “the biggest threat that we, in this space, are all having to fight against now”. She expressed concern that we may need to “prove” that images are “actually real”.
However, she argued that AI will not “win” because, “in the end, authentic images, real stories and real people are what we react to”.
When asked if we expect too much from images, O’Neill argued “we can never pin down a social change to one image, but what we can say is that images both shape and reflect the societies that we live in”. She added:
“I don’t think we can ask photos to do the work that we need to do as a society, but they certainly both shape and show us where the future may lie.”
Watch, read, listen
UNSTOPPABLE WILDFIRES: “Funding cuts, conspiracy theories and ‘powder keg’ pine plantations” are making Patagonia’s wildfires “almost impossible to stop”, said the Guardian.
AUDIO SURVEY: Sverige Radio has published “the world’s, probably, longest audio survey” – a six-hour podcast featuring more than 200 people sharing their questions around climate change.
UNDERSTAND CBAM: European thinktank Bruegel released a podcast “all about” the EU’s carbon adjustment border mechanism, which came into force on 1 January.
Coming up
- 1 February: Costa Rican general election
- 3 February: UN Environment Programme Adaptation Fund Climate Innovation Accelerator report launch, Online
- 2-8 February: Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) 12th plenary, Manchester, UK
Pick of the jobs
- Climate Central, climate data scientist | Salary: $85,000-$92,000. Location: Remote (US)
- UN office to the African Union, environmental affairs officer | Salary: Unknown. Location: Addis Ababa, Ethiopia
- Google Deepmind, research scientist in biosphere models | Salary: Unknown. Location: Zurich, Switzerland
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
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The post DeBriefed 30 January 2026: Fire and ice; US formally exits Paris; Climate image faux pas appeared first on Carbon Brief.
DeBriefed 30 January 2026: Fire and ice; US formally exits Paris; Climate image faux pas
Electric heat pumps are set to play a key role in the UK’s climate strategy, as well as cutting the nation’s reliance on imported fossil fuels.
Heat pumps took centre-stage in the UK government’s recent “warm homes plan”, which said that they could also help cut household energy bills by “hundreds of pounds” a year.
Similarly, innovation agency Nesta estimates that typical households could cut their annual energy bills nearly £300 a year, by switching from a gas boiler to a heat pump.
Yet there has been widespread media coverage in the Times, Sunday Times, Daily Express, Daily Telegraph and elsewhere of a report claiming that heat pumps are “more expensive” to run.
The report is from the Green Britain Foundation set up by Dale Vince, owner of energy firm Ecotricity, who campaigns against heat pumps and invests in “green gas” as an alternative.
One expert tells Carbon Brief that Vince’s report is based on “flimsy data”, while another says that it “combines a series of worst-case assumptions to present an unduly pessimistic picture”.
This factcheck explains how heat pumps can cut bills, what the latest data shows about potential savings and how this information was left out of the report from Vince’s foundation.
How heat pumps can cut bills
Heat pumps use electricity to move heat – most commonly from outside air – to the inside of a building, in a process that is similar to the way that a fridge keeps its contents cold.
This means that they are highly efficient, adding three or four units of heat to the house for each unit of electricity used. In contrast, a gas boiler will always supply less than one unit of heat from each unit of gas that it burns, because some of the energy is lost during combustion.
This means that heat pumps can keep buildings warm while using three, four or even five times less energy than a gas boiler. This cuts fossil-fuel imports, reducing demand for gas by at least two-fifths, even in the unlikely scenario that all of the electricity they need is gas-fired.
Since UK electricity supplies are now the cleanest they have ever been, heat pumps also cut the carbon emissions associated with staying warm by around 85%, relative to a gas boiler.
Heat pumps are, therefore, the “central” technology for cutting carbon emissions from buildings.
While heat pumps cost more to install than gas boilers, the UK government’s recent “warm homes plan” says that they can help cut energy bills by “hundreds of pounds” per year.
Similarly, Nesta published analysis showing that a typical home could cut its annual energy bill by £280, if it replaces a gas boiler with a heat pump, as shown in the figure below.
Nesta and the government plan say that significantly larger savings are possible if heat pumps are combined with other clean-energy technologies, such as solar and batteries.
Both the government and Nesta’s estimates of bill savings from switching to a heat pump rely on relatively conservative assumptions.
Specifically, the government assumes that a heat pump will deliver 2.8 units of heat for each unit of electricity, on average. This is known as the “seasonal coefficient of performance” (SCoP).
This figure is taken from the government-backed “electrification of heat” trial, which ran during 2020-2022 and showed that heat pumps are suitable for all building types in the UK.
(The Green Britain Foundation report and Vince’s quotes in related coverage repeat a number of heat pump myths, such as the idea that they do not perform well in older properties and require high levels of insulation.)
Nesta assumes a slightly higher SCoP of 3.0, says Madeleine Gabriel, the organisation’s director of sustainable future. (See below for more on what the latest data says about SCoP in recent installations.)
Both the government and Nesta assume that a home with a heat pump would disconnect from the gas grid, meaning that it would no longer need to pay the daily “standing charge” for gas. This currently amounts to a saving of around £130 per year.
Finally, they both consider the impact of a home with a heat pump using a “smart tariff”, where the price of electricity varies according to the time of day.
Such tariffs are now widely available from a variety of energy suppliers and many have been designed specifically for homes that have a heat pump.
Such tariffs significantly reduce the average price for a unit of electricity. Government survey data suggests that around half of heat-pump owners already use such tariffs.
This is important because on the standard rates under the price cap set by energy regulator Ofgem, each unit of electricity costs more than four times as much as a unit of gas.
The ratio between electricity and gas prices is a key determinant of the size and potential for running-cost savings with a heat pump. Countries with a lower electricity-to-gas price ratio consistently see much higher rates of heat-pump adoption.
(Decisions taken by the UK government in its 2025 budget mean that the electricity-to-gas ratio will fall from April, but current forecasts suggest it will remain above four-to-one.)
In contrast, Vince’s report assumes that gas boilers are 90% efficient, whereas data from real homes suggests 85% is more typical. It also assumes that homes with heat pumps remain on the gas grid, paying the standing charge, as well as using only a standard electricity tariff.
Prof Jan Rosenow, energy programme leader at the University of Oxford’s Environmental Change Institute, tells Carbon Brief that Vince’s report uses “worst-case assumptions”. He says:
“This report cherry-picks assumptions to reach a predetermined conclusion. Most notably, it assumes a gas boiler efficiency of 90%, which is significantly higher than real-world performance…Taken together, the analysis combines a series of worst-case assumptions to present an unduly pessimistic picture.”
Similarly, Gabriel tells Carbon Brief that Vince’s report is based on “flimsy data”. She explains:
“Dale Vince has drawn some very strong conclusions about heat pumps from quite flimsy data. Like Dale, we’d also like to see electricity prices come down relative to gas, but we estimate that, from April, even a moderately efficient heat pump on a standard tariff will be cheaper to run than a gas boiler. Paired with a time-of-use tariff, a heat pump could save £280 versus a boiler and adding solar panels and a battery could triple those savings.”
What the latest data shows about bill savings
The efficiency of heat-pump installations is another key factor in the potential bill savings they can deliver and, here, both the government and Vince’s report take a conservative approach.
They rely on the “electrification of heat” trial data to use an efficiency (SCoP) of 2.8 for heat pumps. However, Rosenow says that recent evidence shows that “substantially higher efficiencies are routinely available”, as shown in the figure below.
Detailed, real-time data on hundreds of heat pump systems around the UK is available via the website Heat Pump Monitor, where the average efficiency – a SCoP of 3.9 – is much higher.
Homes with such efficient heat-pump installations would see even larger bill savings than suggested by the government and Nesta estimates.
Academic research suggests that there are simple and easy-to-implement reasons why these systems achieve much higher efficiency levels than in the electrification of heat trial.
Specifically, it shows that many of the systems in the trial have poor software settings, which means they do not operate as efficiently as their heat pump hardware is capable of doing.
The research suggests that heat pump installations in the UK have been getting more and more efficient over time, as engineers become increasingly familiar with the technology.
It indicates that recently installed heat pumps are 64% more efficient than those in early trials.
Notably, the Green Britain Foundation report only refers to the trial data from the electrification of heat study carried out in 2020-22 and the even earlier “renewable heat premium package” (RHPP). This makes a huge difference to the estimated running costs of a heat pump.
Carbon Brief analysis suggests that a typical household could cut its annual energy bills by nearly £200 with a heat pump – even on a standard electricity tariff – if the system has a SCoP of 3.9.
The savings would be even larger on a smart heat-pump tariff.
In contrast, based on the oldest efficiency figures mentioned in the Green Britain Foundation report, a heat pump could increase annual household bills by as much as £200 on a standard tariff.
To support its conclusions, the report also includes the results of a survey of 1,001 heat pump owners, which, among other things, is at odds with government survey data. The report says “66% of respondents report that their homes are more expensive to heat than the previous system”.
There are several reasons to treat these findings with caution. The survey was carried out in July 2025 and some 45% of the heat pumps involved were installed between 2021-23.
This is a period during which energy prices surged as a result of Russia’s invasion of Ukraine and the resulting global energy crisis. Energy bills remain elevated as a result of high gas prices.
The wording of the survey question asks if homes are “more or less expensive to heat than with your previous system” – but makes no mention of these price rises.
The question does not ask homeowners if their bills are higher today, with a heat pump, than they would have been with the household’s previous heating system.
If respondents interpreted the question as asking whether their bills have gone up or down since their heat pump was installed, then their answers will be confounded by the rise in prices overall.
There are a number of other seemingly contradictory aspects of the survey that raise questions about its findings and the strong conclusions in the media coverage of the report.
For example, while only 15% of respondents say it is cheaper to heat their home with a heat pump, 49% say that one of the top three advantages of the system is saving money on energy bills.
In addition, 57% of respondents say they still have a boiler, even though 67% say they received government subsidies for their heat-pump installation. It is a requirement of the government’s boiler upgrade scheme (BUS) grants that homeowners completely remove their boiler.
The government’s own survey of BUS recipients finds that only 13% of respondents say their bills have gone up, whereas 37% say their bills have gone down, another 13% say they have stayed the same and 8% thought that it was too early to say.
The post Factcheck: What it really costs to heat a home in the UK with a heat pump appeared first on Carbon Brief.
Factcheck: What it really costs to heat a home in the UK with a heat pump
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