The first-ever international conference on the contentious topic of “overshoot” was held last week in a palace in the small town of Laxenburg in Austria.
The three-day conference brought together nearly 200 researchers and legal experts to discuss future temperature pathways where the Paris Agreement’s “aspirational” target to limit global warming to 1.5C is met “from above, rather than below”.
Overshoot pathways are those which exceed the 1.5C limit – before being brought back down again through techniques that remove carbon from the atmosphere.
The conference explored both the feasibility of overshoot pathways and the legal frameworks that could help deliver them.
Researchers also discussed the potential consequences of a potential rise – and then fall – of global temperatures on climate action, society and the Earth’s climate systems.
Speaking during a plenary session, Prof Joeri Rogelj, a professor of climate science and policy at Imperial College London, said that “moving into a world where we exceed 1.5C and have to manage overshoot” was an exercise in “managing failure”.
He said that it was “essential” that this failure was acknowledged, explaining that this would help set out the need to “minimise and manage” the situation and clarify the implications for “near-term action” and “long-term [temperature] reversal”.
Below, Carbon Brief draws together some of the key talking points, new research and discussions that emerged from the event.
- Defining overshoot
- Mitigation ambition and 1.5C viability
- Carbon removal
- Impacts of overshoot
- Adaptation
- Legal implications and loss and damage
- Communication challenges and next steps
Defining overshoot
The study of temperature overshoot has grown in recent years as the prospects of limiting global temperature rise to 1.5C have dwindled.
Conference organiser Dr Carl-Friedrich Schleussner – a senior research scholar at the International Institute for Applied Systems Analysis (IIASA) – explained the event was designed to bring together different research communities working on a “new field of science”.
He told Carbon Brief:
“If we look at [overshoot] in isolation, we may miss important parts of the bigger picture. That’s why we also set out the conference with very broad themes and a very interdisciplinary approach.”
The conference was split between eight conference streams: mitigation ambition; carbon dioxide removal (CDR); Earth system responses; climate impacts; tipping points; adaptation; loss and damage; and legal implications.
There was also a focus on how to communicate the concept of overshoot.
In simple English, “overshoot” means to go past or beyond a limit. But, in climate science, the term implies both a failure to meet a target – as well as subsequent action to correct that failure.
Today, the term is most often deployed to describe future temperature trajectories that exceed the Paris Agreement’s 1.5C limit – and then come back down.
(In the Intergovernmental Panel on Climate Change’s (IPCC’s) fifth assessment cycle, completed in 2014, the term was used to describe a potential rise and then fall of CO2 concentrations above levels recommended to meet long-term climate goals. A recent “conceptual” review of overshoot noted this was because, at the time, CO2 concentrations were the key metric used to contextualise emissions reductions).
The plot below provides an illustration of three overshoot pathways. The most pronounced pathway sees global temperatures rise significantly above the 1.5C limit – before eventually falling back down again as carbon dioxide is pulled from the atmosphere at scale.
In the second and third pathways, global temperature rise breaches the limit by a smaller margin, before either falling enough just to stabilise around 1.5C, or dropping more dramatically due to larger-scale carbon removals.
In an opening address to delegates, Prof Jim Skea, who is the current chair of the IPCC, acknowledged the scientific interpretation of overshoot was not intuitive to non-experts.
“The IPCC has mainly used two words in relation to overshoot – “exceeding” and “limiting”. To a lay person, these can sound like opposites. Yet we know that a single emissions pathway can both exceed 1.5C in the near term and limit warming to 1.5C in the long term.”
Noting that different research communities were using the term differently, Skea urged researchers to be precise with terminology and stick to the IPCC’s definition of overshoot:
“We should give some thought to communication and keep this as simple as possible. When I look at texts, I hear more poetic words like “surpassing” and “breaching”. I would urge you to keep the range of terms as small as possible and make sure that we’re absolutely using them consistently.”
In the glossary for its latest assessment cycle, AR6, the IPCC defines “overshoot” pathways as follows:
IIASA’s Schleussner stressed that not all pathways that go beyond 1.5C qualify as overshoot pathways:
“The most important understanding is that overshoot is not any pathway that exceeds 1.5C. An overshoot pathway is specific to this being a period of exceedance. It is going to come back down below 1.5C.”
Mitigation ambition and 1.5C viability
Perhaps the most prominent topic during the conference was the implications of overshoot for global ambition to cut carbon emissions and the viability of the 1.5C limit.
Opening the conference, IIASA director general Prof Hans Joachim Schellnhuber shared his personal view that “1.5C is dead, 2C is in agony and 3C is looming”.
In a pre-recorded keynote speech, Ralph Regenvanu, Vanuatu’s minister for climate change, called for a rejection of the “normalisation of overshoot” and argued that “we must treat 1.5C as the absolute limit that it is” and avoid backsliding. He added:
“Minimising peak warming must be our lodestar, because every tenth of a degree matters.”
Prof Skea opened his keynote with some theology:
“I’m going to start with the prayer of St Augustine as he struggled with his youthful longings: ‘Lord grant me chastity and continence, but not yet.’ And it does seem that this is the way that the world as a whole is thinking about 1.5C: ‘Lord, limit warming to 1.5C above pre-industrial levels, but not yet.’”
Referencing the “lodestar” mentioned by Regenvanu, Skea warned that it is light years away and, “unless we act with a sense of urgency, [1.5C is] likely to remain just as remote”.
Speaking to Carbon Brief on the sidelines of the conference, Skea added:
“We are almost certain to exceed 1.5C and the viability of 1.5C is now much more referring to the long-term potential to limit it through overshoot.”
Schleussner told Carbon Brief that the framing of 1.5C in the conference is “one that further solidifies 1.5C as the long-term limit and, therefore, provides a backstop against the idea of reducing or backsliding on targets”.
If warming is going to surpass 1.5C, the next question is when temperatures are going to be brought back down again, Schleussner added, noting that there has been no “direct” guidance on this from climate policy:
“The [Paris Agreement’s] obligation to “pursue efforts” [to limit global temperature rise by 1.5C] points to doing it as fast as possible. Scientifically, we can determine what this means – and that would be this century. But there’s no clear language that gives you a specific date. It needs to be a period of overshoot – that is clear – and it should be as short as possible.”
In a parallel session on the “highest possible mitigation ambition under overshoot”, Prof Joeri Rogelj, professor of climate science and policy at Imperial College London, outlined how the recent ruling from the International Court of Justice (ICJ) provides guidance to countries on the level of ambition in their climate pledges under the Paris Agreement, known as “nationally determined contributions” (NDCs). He explained:
“[The ruling] highlights that the level of NDC ambition is not purely discretionary to a state and that every state must do its utmost to ensure its NDC reflects the highest possible ambition to meet the Paris Agreement long-term temperature goal.”
Rogelj presented some research – due to be published in the journal Environmental Research Letters – on translating the ICJ’s guidance “into a framework that can help us to assess whether an NDC indeed is following a standard of conduct that can represent the highest level of ambition”. He showed some initial results on how the first two rounds of NDCs measure up against three “pillars” covering domestic, international and implementation considerations.
In the same session, Prof Oliver Geden, senior fellow and head of the climate policy and politics research cluster at the German Institute for International and Security Affairs and vice-chair of IPCC Working Group III, warned that the concept of returning temperatures back down to 1.5C after an overshoot is “not a political project yet”.
He explained that there is “no shared understanding that, actually, the world is aiming for net-negative”, where emissions cuts and CDR together mean that more carbon is being taken out of the atmosphere than is being added. This is necessary to achieve a decline in global temperatures after surpassing 1.5C.
This lack of understanding includes developed countries, which “you would probably expect to be the frontrunners”, Geden said, noting that Denmark is the “only developed country that has a quantified net-negative target” of emission reductions of 110% in 2050, compared to 1990 levels. (Finland also has a net-negative target, while Germany announced its intention to set one last year. In addition, a few small global-south countries, such as Panama, Suriname and Bhutan, have already achieved net-negative.)
Geden pondered whether developed countries are a “little bit wary to commit to going to net-negative territory because they fear that once they say -110%, some countries will immediately demand -130% or -150%” to pay back a larger carbon debt.
Carbon removal
To achieve a decline in global temperatures after an initial breach of 1.5C would require the world to reach net-negative emissions overall.
There is a wide range of potential techniques for removing CO2 from the atmosphere, such as afforestation, direct air capture and bioenergy with carbon capture and storage (BECCS). Captured carbon must be locked away indefinitely in order to be effective at reducing global temperatures.
However, despite its importance in achieving net-negative emissions, there are “huge knowledge gaps around overshoot and carbon dioxide removal”, Prof Skea told Carbon Brief. He continued:
“As it’s very clear from the themes of this conference, we don’t altogether understand how the Earth would react in taking carbon dioxide out of the atmosphere. We don’t understand the nature of the irreversibilities. And we don’t understand the effectiveness of CDR techniques, which might themselves be influenced by the level of global warming, plus all the equity and sustainability issues surrounding using CDR techniques.”
Skea notes that the seventh assessment cycle of the IPCC, which is just getting underway, will “start to fill these knowledge gaps without prejudging what the appropriate policy response should be”.
Prof Nebojsa Nakicenovic, an IIASA distinguished emeritus research scholar, told Carbon Brief that his “major concern” was whether there would be an “asymmetry” in how the climate would respond to large-scale carbon removal, compared to its response to carbon emissions.
In other words, he explained, would global temperatures respond to carbon removal “on the way down” in the same way they did “on the way up” to the world’s carbon emissions.
Nakicenovic noted that overshoot requires a change in focus to approaching the 1.5C limit “from above, rather than below”.
Schleussner made a similar point to Carbon Brief:
“We may fail to pursue [1.5C] from below, but it doesn’t relieve us from the obligation to then pursue it from above. I think that’s also a key message and a very strong overarching message that’s going to come out from the conference that we see…that pursuing an overshoot and then decline trajectory is both an obligation, but it also is well rooted in science.”
Reporting back to the plenary from one of the parallel sessions on CDR, Dr Matthew Gidden, deputy director of the Joint Global Change Research Institute at the Pacific Northwest National Laboratory, also noted another element of changing focus:
“When we’re talking about overshoot, we have become used to, in many cases, talking about what a net-zero world looks like. And that’s not a world of overshoot. That’s a world of not returning from a peak. And so communicating instead about a net-negative world is something that we could likely be shifting to in terms of how we’re communicating our science and the impacts that are coming out of it.”
On the need for both CDR and emissions cuts, Gidden noted that the discussions in his session emphasised that “CDR should not be at the cost of mitigation ambition”. But, he added, there is still the question of how “we talk about emission reductions needed today, but also likely dependence on CDR in the future”.
In a different parallel session, Prof Geden also made a similar point, noting that “we have to shift CDR from being seen as a barrier to ambition to an enabler of even higher ambition, but not doing that by betting on ever more CDR”.
Among the research presented in the parallel sessions on CDR was a recent study by Dr Jay Fuhrman from the JGCRI on the regional differences in capacity to deploy large-scale carbon removal. Ruben Prütz, from the Potsdam Institute for Climate Impact Research, presented on the risks to biodiversity from large-scale land-based CDR, which – in some cases – could have a larger impact than warming itself.
In another talk, the University of Oxford’s Dr Rupert Stuart-Smith explored how individual countries are “depending very heavily on [carbon] removals to meet their climate targets”. Stuart-Smith was a co-author on an “initial commentary” on the legal limits of CDR, published in 2023. This has been followed up with a “much more detailed legal analysis”, which should be published “very soon”, he added.
Impacts of overshoot
Since the Paris Agreement and the call for the IPCC to produce a special report on 1.5C, research into the impacts of warming at the aspirational target has become commonplace.
Similarly, there is an abundance of research into the potential impacts at other thresholds, such as 2C, 3C and beyond.
However, there is comparatively little research into how impacts are affected by overshoot.
The conference included talks on some published research into overshoot, such as the chances of irreversible glacier loss and lasting impacts to water resources. There were also talks on work that is yet to be formally published, such as the risks of triggering interacting tipping points under overshoot.
Speaking in a morning plenary, Prof Debra Roberts, a coordinating lead author on the IPCC’s forthcoming special report on climate change and cities and a former co-chair of Working Group II, highlighted the need to consider the implications of different durations and peak temperatures of overshoot.
For example, she explained, it is “important to know” whether the impacts of “overshoot for 10 years at 0.2C above 1.5C are the same as 20 years at 0.1C of overshoot”.
Discussions during the conference noted that the answer may be different depending on the type of impact. For heat extremes, the peak temperature may be the key factor, while the length of overshoot will be more relevant for cumulative impacts that build up over time, such as sea level rise.
Similarly, if warming is brought back down to 1.5C after overshoot, what happens next is also significant – whether global temperature is stabilised or net-negative emissions continue and warming declines further. Prof Schleussner told Carbon Brief:
“For example, with coastal adaptation to sea level rise, the question of how fast and how far we bring temperatures back down again will be decisive in terms of the long-term outlook. Knowing that if you stabilise that around 1.5C, we might commit two metres of sea level rise, right? So, the question of how far we can and want to go back down again is decisive for a long-term perspective.”
One of the eight themes of the conference centred specifically on the reversibility or irreversibility of climate impacts.
In his opening speech, Vanuatu’s Ralph Regenvanu warned that “overshooting 1.5C isn’t a temporary mistake, it is a catalyst for inescapable, irreversible harm”. He continued:
“No level of finance can pull back the sea in our lifetimes or our children’s. There is no rewind button on a melted glacier. There is no time machine for an extinct species. Once we cross these tipping points, no amount of later ‘cooling’ can restore our sacred reefs, it cannot regrow the ice that already vanished and it cannot bring back the species or the cultures erased by the rising tides.”
As an example of a “deeply, deeply irreversible” impact, Dr Samuel Lüthi, a postdoctoral research fellow in the Institute of Social and Preventive Medicine at the University of Bern, presented on how overshoot could affect heat-related mortality.
Using mortality data from 850 locations across the world, Lüthi showed how projections under a pathway where warming overshoots 1.5C by 0.1-0.3C, before returning to 1.5C by 2100 has 15% more heat-related deaths in the 21st century than a pathway with less than 0.1C of overshoot.
His findings also suggested that “10 years of 1.6C is very similar [in terms of impacts] to five years of 1.7C”.
Extreme heat also featured in a talk by Dr Yi-Ling Hwong, a research scholar at IIASA, on the implications of using solar geoengineering to reduce peak temperatures during overshoot.
She showed that a world where a return to 1.5C had been achieved through geoengineering would see different impacts from a world where 1.5C was reached through cutting emissions. For example, in her modelling study, while geoengineering restores rainfall levels for some regions in the global north, significant drying “is observed in many regions in the global south”.
Similarly, a world geoengineered to 1.5C would see extreme nighttime heat in some tropical regions that is more severe than in a 2C world with no geoengineering, Hwong added.
In short, she said, “this implies the risk of creating winners and losers” under solar geoengineering and “raises concerns about equity and accountability that need to be considered”.
After describing how overshoot features in the outlines of the forthcoming AR7 reports in his opening speech, Prof Skea told Carbon Brief that he expects a “surge of papers” on overshoot in time to be included.
But it was important to emphasise that a “lot of the science that people have been carrying out is relevant within or without an overshoot”, he added:
“At points in the future, we are not going to know whether we’re in an overshoot world or just a high-emissions world, for example. So a lot of the climate research that’s been done is relevant regardless of overshoot. But overshoot is a new kind of dimension because of this issue of focus on 1.5C and concerns about its viability.”
Adaptation
The implications of overshoot temperature pathways for efforts to prepare cities, countries and citizens for the impacts of climate change remains an under-researched field.
Speaking in a plenary, Prof Kristie Ebi – a professor at the University of Washington’s Center for Health and the Global Environment – described research into adaptation and overshoot as “nascent”. However, she stressed that preparing society for the impacts associated with overshoot pathways was as important as bringing down emissions.
She told Carbon Brief that there were “all kinds of questions” about how to approach “effective” adaptation under an overshoot pathway, explaining:
“At the moment, adaptation is primarily assuming a continual increase in global mean surface temperature. If there is going to be a peak – and, of course, we don’t know what that peak is – then how do you start planning? Do you change your planning? There are places, for instance when thinking about hard infrastructure, [where overshoot] may result in a change in your plan.”
IIASA’s Schleussner told Carbon Brief that the scientific community was only just “beginning to appreciate” the need to understand and “quantify” the implications of different overshoot pathways on adaptation.
In a parallel session, Dr Elisabeth Gilmore, associate professor in environmental engineering and public policy at Carleton University in Canada, made the case for overshoot modelling pathways to take greater account of political considerations.
“Not just, but especially, in situations of overshoot, we need to start thinking about this as much as a physical process as a socio-political process…If we don’t do this, we are really missing out on some key uncertainties.”
Current scenarios used in climate research – including the Shared Socioeconomic Pathways and Representative Concentration Pathways – are “a bit quiet” when it comes to thinking about governance, institutions and peace and conflict, Gilmore said. She added:
“Political institutions, legitimacy and social cohesion continue to shift over time and this is really going to shape how much we can mitigate, how much we adapt and especially how we would recover when adding in the dimension of overshoot.”
Gilmore argued that, from a social perspective, adaptation needs are greatest “before the peak” of temperature rise – because this is when society can build the resilience to “get to the other side”. She said:
“Orthodoxy in adaptation [research] that you always want to plan for the worst [in the context of adaptation, peak temperature rise]… But we don’t really know what this peak is going to be – and we know that the politics and the social systems are much more messy.”
Dr Marta Mastropietro, a researcher at Politecnico di Milano in Italy, presented the preliminary results of a study that used emulators – simple climate models – to explore how human development might be impacted under low, medium and high overshoot pathways.
Mastropietro noted how, under all overshoot scenarios studied, both the drop to the human development index (HDI) – an index which incorporates health, knowledge and standard of living – and uncertainty increases as the peak temperature increases.
However, she said “the most important takeaway” from the preliminary results was around society’s constrained ability to recover from damage.
“This percentage of damages that are absorbed is always less than 50%. So, even in the most optimistic scenarios of overshoot, we will not be able to reabsorb these damages, not even half of them. And this is considering a damage function which does not consider irreversible impacts like sea level rise.”
Meanwhile, Dr Inês Gomes Marques from the University of Lisboa in Portugal, shared the results of an as-yet-unpublished study investigating whether the Lisbon metropolitan area holds enough public spaces to offer heatwave relief to the population under overshoot scenarios. The 1,900 “climate refugia” counted by researchers included schools, museums and churches.
Marques noted that most of the population were found to be within one kilometre of a “climate refugia” – but noted that “nuances” would need to be added to the analysis, including a function which considers the limited mobility of older citizens.
She explained that the researchers were aiming to “establish a framework” for this type of analysis that would be relevant to both the science community and municipalities tasked with adaptation. She added:
“The main point is that we need to think about this now, because we will face some big problems if we don’t”.
Legal implications and loss and damage
Significant attention was given throughout the conference to the legal considerations of the breach of – and impetus to return to – the Paris Agreement’s 1.5C warming limit.
This included discussions about how the international legal frameworks should be updated for an “overshoot” world where countries would need to pursue “net-negative” strategies to bring temperatures down to 1.5C.
There were also discussions around governance of geoengineering technologies and the fairness and justice considerations that arise from the real-world impacts of breached targets.
The conference was being held just months after the ICJ’s advisory decision that limiting temperature increase to 1.5C should be considered countries’ “primary temperature goal”.
IIASA’s Shleussner told Carbon Brief that the decision provided “clarity” that countries had a “clear obligation to bring warming back to 1.5C”. He added:
“We may fail to pursue it from below, but it doesn’t relieve us from the obligation to then pursue it from above.”
Prof Lavanya Rajamani, professor of international environmental law at the University of Oxford, insisted that “1.5C was very much alive and well in the legal world”, but noted there were “very significant limits” to what could be achieved through the UN Framework Convention for Climate Change (UNFCCC) – the global treaty for coordinating the response to climate change – both today and in the future.
Summarising discussions around how countries can be pushed to deliver the “highest possible ambition” in future climate plans submitted to the UN, Rajamani urged delegates to be “tempered in [its] expectations of what we’re going to get from the international regime”. She added:
“Changing the narratives and practices at the national level are far more likely to filter up to the international level than trying to do it from a top-down perspective.”
In a parallel session, Prof Christina Voigt, a professor of international law at the University of Oslo, pointed out that overshoot would require countries to aspire beyond “net-zero emissions” as “the end climate goal” in national plans.
Stabilising emissions at “net-zero” by mid-century would result in warming above 1.5C, she explained, whereas “net-negative” emissions are required to deliver overshoot pathways that return temperatures to below the Paris Agreement’s aspirational limit. She continued:
“We will need frontrunners. Leaders, states, regions would need to start considering negative-emission benchmarks in their climate policies and laws from around mid-century. There will be an expectation that developed country parties take the lead and explore this ‘negativity territory’.”
Voigt added that it was “critical” that nations at the UNFCCC create a “shared understanding” that 1.5C remains the “core target” for nations to aim for, even after it has been exceeded. One possible place for such discussions could be at the 2028 global stocktake, she noted.
She said there would need to be more regulation to scale up CDR in a way that addresses “environmental and social challenges” and an effort to “recalibrate policies and measures” – including around carbon markets – to deliver net-negative outcomes.
In a presentation exploring governance of solar radiation management (SRM), Ewan White, a DPhil student in environmental law at the University of Oxford, said the ICJ’s recent advisory opinion could be interpreted to be “both for and against” solar geoengineering.
Countries tasked with drawing up global rules around SRM in an overshoot world would need to take a “holistic approach to environmental law”, White said. In his view, this should take into account international legal obligations beyond the Paris Agreement and consider issues of intergenerational equity, biodiversity protection and nations’ duty to cooperate.
Dr Shonali Pachauri, research group leader at IIASA, provided an overview of the equity and justice implications that might arise in an overshoot world.
First, she said that delays to emissions reductions today are “shifting the burden” to future generations and “others within this generation” – increasing the need for “corrective justice” and potential loss-and-damage payments.
Second, she said that adaptation efforts would need to increase – which, in turn, would “threaten mitigation ambition” given “constrained decision-making”.
Finally, she pointed to resource consumption issues that might arise in a world of overshoot:
“The different technologies that one might use for CDR often depend on the use of land, water, other materials – and this, of course, then means competing with many other uses [of resources].”
A separate stream focused on loss and damage. Session chair Dr Sindra Sharma, international policy lead at the Pacific Islands Climate Action Network, noted that the concept of loss and damage was “fundamentally transformed” by overshoot – adding there were “deep issues of justice and equity”.
However, Sharma said that the literature on loss and damage “has not yet deeply engaged with the specific concept of overshoot” despite it being “an important, interconnected issue”.
Sessions on loss and damage explored the existence of “hard social limits” under future overshoot scenarios, insurance and the need to bring more factors into assessments of habitability, including biophysical and social-economic constraints.
Communication challenges and next steps
At the conference, scientists and legal experts collaborated on a series of statements that summarised discussions at the conference – one for each research theme and an overarching umbrella statement.
IIASA’s Schleussner told Carbon Brief that the statements represented a “key outcome of the conference” that could provide a “framework” to guide future research.
Nevertheless, he noted that statements are a “work in progress” and set to be “further refined” following feedback from experts not able to attend the conference.
At the time of going to press, the overarching conference statement read as follows:
“Global warming above 1.5C will increase irreversible and unacceptable losses and damages to people, societies and the environment.
“It is imperative to minimise both the maximum warming and duration of overshoot above 1.5C to reduce additional risks of human rights violations and causing irreversible social, ecological and Earth system changes including transgressing tipping points.
“This is required by international law and possible by removing CO2 from the atmosphere and further reducing remaining greenhouse emissions.”
Conference organisers also pointed delegates to an open call for research on “pathways and consequences of overshoot” in the journal Environmental Research Letters. The special issue will be guest edited by a number of scientists who played a key role in the conference.
Meanwhile, communications experts at the conference discussed the challenges inherent in conveying overshoot science to non-experts, noting potential confusion around the word “overshoot” and the difficulties in explaining that the 1.5C limit, while breached, was still a goal.
Holly Simpkin, communications manager at the Potsdam Institute for Climate Impact Research, urged caution when communicating overshoot science to the general public:
“I don’t know whether ‘overshoot’ is an effective communication framing. It is an important scientific question, but when it comes to near-term action and the requirements that an ambitious overshoot pathway would ask of us, emissions are what are in our control.
“We could spend 10 more years defining this and, actually, it’s quite complex…I think it’s better to be honest about that and to try to be more simple in that frame of communication, knowing that this community is doing a wealth of work that provides a technical basis for those discussions.”
The post Overshoot: Exploring the implications of meeting 1.5C climate goal ‘from above’ appeared first on Carbon Brief.
Overshoot: Exploring the implications of meeting 1.5C climate goal ‘from above’
Climate Change
Foreign minister: Nepal needs “meaningful” international support to face climate threats
In the wake of the recent flash flood that swept down from the Himalayas, Nepal is seeking immediate aid from a UN fund for climate loss and damage to help vulnerable families displaced by the disaster and rebuild destroyed schools and hospitals, the country’s foreign minister told Climate Home News.
“This is exactly the kind of climate-driven catastrophe the Fund was created to address,” Shisir Khanal said in an interview. He added that “stronger global solidarity and meaningful international support” are needed for countries like Nepal, which are facing increasingly severe climate-related disasters.
The floods were caused by a glacier collapsing and triggering a landslide that forced a torrent of water and debris to rush down the Bhote Koshi River valley, causing catastrophic impacts downstream. More than 1,300 people died and over 5,300 are still missing in the area.
Khanal described the disaster as a “Himalayan tsunami”, telling Climate Home News that early assessments suggest the roads, bridges, hydropower stations, highways and settlements it wiped out could require billions of dollars to rebuild. Reconstruction estimates by the government range between $2.5 billion and $5 billion.
The minister of foreign affairs said Nepal would not be asking the UN’s new Fund for Responding to Loss and Damage (FRLD) “to write a single check for this total amount”, explaining that the government is finalising a post-disaster assessment “to guide our broader international donor appeals”.
Nepal disaster seen as test case for fledgling fund
In reality, if Nepal does receive rapid support from the FRLD, it is likely to be a fraction of the total bill because the fund has a cap of $20 million per project and has little more than $350 million available to hand out in its initial phase.
So far its board has not approved any projects as it is still working out how to allocate its scarce resources, nor does it have a process in place to respond to sudden climate disasters such as glacial lake outburst floods or powerful storms.
On August 31, Nepal’s government sent a direct appeal for emergency grant funding to the FRLD, emphasising that “a prompt response would… demonstrate that the fund can translate international solidarity into timely support for vulnerable countries and communities when it is most urgently needed”.
A couple of days later, eight developing-country board members – later joined by those from small island states – signed a letter, seen by Climate Home News, asking the fund’s board to hold an extraordinary meeting to respond to Nepal’s request.
The FRLD said in a statement that the devastating impacts on the ground “underscore both the urgency and scale of need and reaffirm the fundamental purpose for which the FRLD was established”.
It added that it is “committed to approaching Nepal’s request with the urgency, compassion, and careful consideration that these difficult circumstances require, while respecting the Fund’s governing instrument and established decision-making processes”. As of Wednesday, Climate Home News understands that discussions were still ongoing.
Designing infrastructure for extreme shocks
Khanal pointed to “the unprecedented scale” of the huge flood which occurred within a matter of minutes and swept away river gauges meant to provide early warning in Rasuwa and Nuwakot, near the border with Tibet.
“You cannot easily ‘plan’ against a mountain collapsing,” he said. But the lesson, he added in written responses in English, is that “our historical baseline for infrastructure engineering is no longer sufficient”.
Building resilient infrastructure means that “hydropower projects, roads and early warning systems must be designed for extreme, unpredictable climate shocks”, he said. Another key element will be plans to better understand and protect ecosystems, he added.
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The minister noted that Nepal, India and China share a common, interconnected Himalayan ecosystem and all three countries are affected by the impacts of climate change in the Himalayan mountain chain.
“Therefore, our call is for the three countries to work together to strengthen preparedness, resilience and regional cooperation,” he said.
New research from consultancy Systemiq, released on Wednesday, finds that Himalayan glaciers are losing mass 65% faster than a decade ago, and that only around 20 of the Himalaya’s estimated 40,000 glaciers are currently monitored. India alone has 56 glacial lakes rated very high risk, it warns.
Early cross-border efforts on information-sharing
Since the same region of Nepal was hit by smaller-scale but still highly destructive flooding in 2024 and 2025, China and Nepal have stepped up efforts to cooperate in tackling glacier-related risks in the region.
In August 2025, Climate Home News reported that authorities in both countries had agreed to share cross-border information about the risks of glacial lake outburst floods across the Tibetan region, in a first step that could be expanded to the national level in an effort to reduce deaths and damage.
This May, a delegation from China’s Ministry of Water Resources and the Water Resources Department of the Xinjiang Autonomous Region held talks with Nepalese officials in charge of water and disaster management about establishing a joint disaster information mechanism.
Then in August, a team from the Institute of Mountain Hazards and Environment under the Chinese Academy of Sciences also visited Nepal for scientific research and exchange, sharing China’s experience in monitoring glacial lakes.
Nepal and China agree to cooperate on glacial lake flooding, as warming hikes threat
However, experts told Climate Home News that progress on putting in place concrete measures has been slow. Narendra Khanal, a professor in the department of geography at Tribhuvan University, blamed that partly on Nepal’s traditional administrative system and bureaucratic delays.
“We have to share information with them, and they have to share information with us,” he said. “In my understanding, the Chinese side is also facing difficulties in making this cooperation work.”
Mohan Bahadur Chand, a Himalayan glaciologist and assistant professor at Kathmandu University, said China has the technology and human resources to provide significant information to its neighbour downstream.
But, to make that work, “we have to build trust between the two countries”, which is currently lacking but could be developed, he said. “As scientists, we are already working with them personally. If we create a trusted environment, cooperation should not be difficult.”
Nepal lacks monitoring and warning technology
Experts said Nepal – one of the world’s least-developed countries – does not have the technology or resources to install the sophisticated monitoring and warning systems needed to protect its population from growing threats linked to accelerating glacier melt in the Himalayas.
A senior meteorologist at the Department of Hydrology and Meteorology, who did not want to be named, told Climate Home News that the government had not invested enough in rainfall and weather monitoring stations, especially above 3,500 metres, and therefore lacks reliable data about what is happening at high altitudes.
“The stations we have are operated by different organisations, but many of them are not functioning properly,” the official added.
Comment: The loss and damage fund needs far more finance to deliver climate justice
This year, the UN’s Green Climate Fund released initial funding for a $50-million project to address the risks from four glacial lakes in other parts of Nepal, but has come under criticism for taking seven years to approve the proposal. The fund said this was due to efforts needed to strengthen and consult on the project, as well as administrative, institutional and COVID-related delays.
Foreign minister Khanal said Nepal was calling on the international community for support to tackle global warming impacts into the future.
“This disaster should not be viewed simply as a one-time event requiring one-time assistance,” he emphasised. “We need to recognise the longer-term consequences of rising temperatures and climate change, particularly for vulnerable communities and developing countries.”
The post Foreign minister: Nepal needs “meaningful” international support to face climate threats appeared first on Climate Home News.
Foreign minister: Nepal needs “meaningful” international support to face climate threats
Amy Youngman is a legal and policy specialist at the campaigning group Environmental Investigation Agency (EIA).
The chair’s August Aid to Negotiations is being sold as a pragmatic way to rescue the global plastics treaty. However, the text is starting to resemble the architecture of a Paris Agreement-style framework: a patchwork of vague commitments, nationally determined action and reporting, with the hardest substantive decisions left to a future that, my experience following these negotiations tells me, would never arrive.
In March 2022, governments adopted UNEA Resolution 5/14 by consensus, launching negotiations for a legally binding international instrument to end plastic pollution. I joined the global plastics treaty process in Paris in 2023, where hopes of drafting a treaty capable of confronting one of the defining environmental and human health threats of our time were first derailed by procedural warfare.
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“We’ve gone backwards” – new plastics treaty text dims hopes for production curbs
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Five months later, in Nairobi, I watched the chair close a meeting while delegates still negotiated -allegedly to catch a flight. In 2024 and 2025, in Ottawa, Busan and Geneva, the same small group of blocking states grew bolder, cloaking opposition in language about defending the vulnerable while subsidising a system that fuels the pollution crisis. Offended by ambition, ashamed of nothing.
A year after the last formal attempt to negotiate a treaty, we are tasked with protecting a fragile process. And despite long-standing support, including legal, policy and technical expertise from my own Environmental Investigation Agency, the chair has excluded observers from the rooms where the treaty’s fate is being decided.
In that orchestrated quiet, the loudest proposal emerged: the suggestion that the instrument be a “framework convention.” The new Aid, intended to shape the late-September Heads of Delegation meeting, never uses the word “framework”. It does not need to. It strips back substantive obligations and presupposes future action.
A framework is no match for this crisis
Framework conventions outline broad principles and leave each country to develop its own plan, often delaying tough decisions to future negotiations that may never happen. This tactic is a political shell game: persuading states that want action now to give up meaningful, binding measures to reach agreement.
The Chair’s Aid arrives at a framework by subtraction rather than by proposal, which makes it harder to name and potentially easier to accept. Using the Aid, effectively the rejected text from Geneva, as a basis for the next informal meeting in Bangkok will be sold as a way to preserve a distressed UN system and reach consensus in a fractured geopolitical environment.
This is diplomacy drowning in wishful thinking that the countries fighting binding rules today will approve tougher ones tomorrow. Four years of negotiations and decades of climate diplomacy taught us that this is not a bridge to ambition – this is how ambition dies.
Production is driven by global oil, gas and chemical markets, while products and waste travel across borders. No singular government can regulate its way out of a problem created and amplified by a globalised system.
Countries have tried, and production kept rising. Now there is plastic everywhere we look, and the cost falls hardest on the people least responsible.
That failure is why there was consensus to negotiate a treaty, because this crisis requires global action. The purpose was never to list national efforts and call that progress but to create common global rules to address pollution.
The most politically sensitive issues cannot simply be postponed. How much plastic is produced, which toxic chemicals are allowed in it, which throwaway products are banned, and how future decisions are made are precisely the issues that require global answers. An instrument that refuses to negotiate them will be easier to adopt but useless on arrival.
Learn from climate governance
Supporters of a framework approach may point to the ozone treaty as proof that it can work. But the Vienna Convention succeeded for one reason: governments quickly adopted binding upstream controls on ozone-depleting substances.
Climate offers the opposite warning: a framework followed by contested, delayed and insufficient measures, while emissions keep rising.
The new chair not only deleted a direct reference to “production and consumption” and bracketed similar preambular language copied from the original mandate. The article on reporting borrows language from the Paris Agreement. Another summer of record heat, fires and floods offers a glimpse of how well that model is working.
Nothing suggests that the states blocking binding rules today will suddenly accept them tomorrow, and the exponential rise in unchecked plastic production will not pause while governments wait for courage. Blockage is not being resolved, but just pushed forward.
A framework would lock in the wrong response: unlimited upstream growth with waste management attempting to handle it downstream. No waste system can keep pace with a material engineered for endless growth.
Keeping to 1.5C of warming is no longer possible – but we must still limit the overshoot
After four years of INC negotiations, governments know this. States must reject the false choice that the only path to agreement is an instrument too weak to solve the problem it was created to address. Compromise is part of diplomacy. Surrender is not.
And if the UN keeps pushing that choice, the countries prepared to act must be willing to pursue alternative pathways. Groups of willing governments have built effective agreements before, and existing environmental regimes can deliver new rules without inventing a new empty instrument.
This process was never meant to find a lowest common denominator. It was to create the rules necessary to change our direction. Bangkok in September will be where the second iteration of this text is shaped. If ambitious countries do not push back, the argument about a framework convention will already be lost by default.
Negotiations cannot end with governments accepting the crisis rather than solving it. The science is clear and the damage is accelerating. The world does not need another promise to act later. It needs the treaty governments promised to deliver in 2022.
The post The world doesn’t need a Paris Agreement for plastics appeared first on Climate Home News.
Climate Change
As science comes under attack at UN talks, climate movement splits over how to respond
With June’s UN climate talks inching towards gridlock, a group of diplomats calling themselves “Friends of Science” issued a stark warning: climate science was under attack in Bonn.
The coalition, spanning the world’s richest to its most vulnerable nations, pointed the finger primarily at those who think “science threatens their economic prospects” – a thinly-veiled reference to fossil fuel-dependent states accused of casting doubt on long-held scientific tenets in the UN climate process.
Fiji’s lead negotiator, Sivendra Michael, went still further. He denounced what he called “a very polluted narrative” taking hold outside the negotiating rooms and singled out ECO, a daily newsletter on the talks produced by Climate Action Network (CAN) International, for overlooking the issue.
“They are representing developing countries, but they are not representing us,” Michael said. His words hinted at how a rift between governments over the science of global warming has created tensions inside the climate movement.
Watchers of the UN climate talks have told Climate Home News there is growing unease over where the world’s most influential coalition of climate NGOs stands in an increasingly heated debate about how scientific messages produced by the Intergovernmental Panel on Climate Change (IPCC) are crafted and turned into global climate policy.
UN sets out narrow path back to 1.5C warming after inevitable overshoot
CAN’s international leadership has publicly backed a line of argument, championed by some big emerging economies including India, that questions how fair and equitable the models underpinning the work of the IPCC – the UN’s climate science body – are because they are dominated by research from the Global North.
But some climate activists, including from nations on the frontline of the climate crisis in the Pacific, are increasingly disappointed by CAN’s silence in a connected row over whether the IPCC’s forthcoming assessment report should be finished in time to inform the next UN scorecard of global climate action.
Over the last two years, India, Saudi Arabia, China, Russia and Kenya have pushed back against attempts by a large coalition of nations to align the IPCC’s AR7 report timeline with the second stocktake of national climate plans under the UN climate process. They claim this would put a burden on developing countries with limited resources and restrict their ability to provide scientific input into the process.
India flags bias in IPCC assumptions
CAN International Executive Director Tasneem Essop spoke at an online event last month in which panelists challenged the “Friends of Science” campaign launched at the Bonn talks.
During the webinar, an Indian scientist and government negotiator set out her view that the IPCC’s way of working and scientific assumptions perpetuate inequity between developed and developing countries – and yet its reports have come to be treated as “scripture” that cannot be questioned.
In her intervention, Essop did not comment directly on the Bonn science campaign nor on the IPCC timeline issue. But the participation of CAN’s leadership in an event where such criticism of the IPCC was aired has sparked concern in some parts of the NGO community.
“The way in which CAN International is playing into what could be the destruction of the IPCC inputs into the climate process is very concerning,” said Bill Hare, who was involved in CAN’s establishment nearly four decades ago and now runs think-tank Climate Analytics.
Science ‘under attack’ from fossil fuel interests at UN climate talks
He added that it was a mistake for CAN International to align itself with arguments made by India and Saudi Arabia, when those countries are blocking the conclusion of the IPCC’s next key report on cutting emissions in time for it to feed into the next global stocktake, which is due to conclude in 2028.
Like other insiders Climate Home News spoke to, the veteran Australian climate scientist fears these tensions could hamper CAN’s widely recognised power to influence the talks.
“The CAN International voice has been very, very important in the process. That voice doesn’t need to be diluted at this moment in history – that would be a really bad move,” Hare said.
Dialogue to reconcile differing views
Over the last decade, CAN has been working to transform itself into an organisation that is more representative of, and responsive to, voices and needs in the Global South. In 2019, it appointed Essop – a South African expert on climate, energy, poverty and social justice – as executive director, shifting further away from its European and North American roots.
CAN International, which functions as the broader network’s secretariat, says it is discussing how to reconcile varying views on the IPCC and the science and equity question among its hundreds of member groups spread across 130 countries.
“We acknowledge that there are different perspectives within a global network of over 2,000 members on these issues,” CAN International’s Essop said in response to questions from Climate Home News. “Given this diversity, we have democratic processes to build internal agreements.”
“Science and equity are both fundamental principles for effective climate action and are firmly embedded in CAN’s work,” she added in a written statement. “Putting these principles into practice in a painfully unjust world is not always straightforward, which is why we need continued dialogue across the network.”
Calls for “fair share” approach
The webinar in late August – which aimed to untangle what organisers described as “a growing narrative” that “treats science and equity as opposing priorities” – opened with a presentation by Tejal Kanitkar, a prominent Indian climate scientist who also serves on her government’s delegations at the IPCC and UN climate talks.
Outlining the findings of a paper she co-authored, Kanitkar argued that the IPCC had used scenarios for future emission reduction trajectories based primarily on assumptions put forward by Global North researchers that are skewed against the world’s poorest nations. These, she noted, were then incorporated into the first UN review of global climate action in 2023 and turned into widely cited emissions-cutting targets for limiting warming to 1.5C – a goal the UN has now conceded will be breached, at least temporarily.
Kanitkar said the “Friends of Science” group included “some of the people who have over-consumed the carbon budget and now use science as a slogan”. When Climate Home News raised the participation of diplomats from vulnerable countries, she said they should be asked why they “accept outcomes that burden the poorest the most”.
Commenting on Kanitkar’s presentation, CAN’s Essop said everyone knows that “imbalances of power dictate who sits at the table, who designs the models and who determines the assumptions underlying them”.
Her wider intervention focused more generally on the need to ensure that emissions-reduction pathways follow an equitable approach and account for the “fair share” of action countries need to take based on their historical responsibilities for climate change.
IPCC working to update models
Hare later acknowledged that most of the IPCC models used for 1.5C scenarios fail to account for the higher cost of capital and transition financing faced by developing countries. But as this is a “well-known” limitation, the IPCC gives a nuanced reading of the scenarios, and the next generation of models it uses is expected to include more consideration of equity, he added.
Echoing this, a climate scientist from a developing country currently involved in the IPCC process, who did not want to be identified, told Climate Home News that economic models inevitably contain biases and IPCC authors are already working to identify and correct them.
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We need a strategy for navigating the huge risks to ecosystems and societies
Despite criticisms of how IPCC scientific reports have been produced, all governments must sign off on every line of a key “summary for policy-makers” at a dedicated meeting. In 2023, the approved summary included the emissions reduction figures in question that informed the UN’s first global stocktake.
Irrespective of this wider debate, Hare said the “Friends of Science” campaign, which he supports, is focused on the timing of the IPCC’s next assessment cycle rather than the equity of its models.
Unresolved row over IPCC report timeline
A political battle over that time-frame has dragged on for more than two years at successive meetings of the science panel, with governments repeatedly failing to find a solution.
A large majority of nations have been pushing for a timeline that would ensure the next round of AR7 reports can feed into the UN’s global stocktake. But a group of countries, including Saudi Arabia, India, China, Russia and Kenya, have said at previous IPCC meetings that this would put a burden on developing countries with limited resources and have lobbied for a longer process.
In Bonn this summer, the coalition that wants to align AR7 with the 2028 stocktake – which includes diplomats from Fiji, Nepal, the European Union, Switzerland, Sierra Leone and Panama – vowed to ensure that decision-making in the UN climate process remains based on the “best available science”, including the IPCC assessment reports.
They pointed the finger at “the usual suspects” but stopped short of singling out any countries at the public press conference. Discussions in the previous week had seen Saudi Arabia and India play down the centrality of IPCC reports in the UN stocktake and oppose calls in draft texts to encourage scientific work on scenarios to limit an overshoot of the 1.5C warming goal.
Bonn upset fuels further tension
A campaigner with knowledge of internal discussions told Climate Home News that many civil society groups from some of the world’s most vulnerable nations, including the Pacific islands, had expected CAN International to back calls in Bonn defending the centrality of the IPCC in UN climate policy-making.
Despite this, a day before the “Friends of Science” press conference, CAN published an ECO newsletter that did not mention the issue. Instead, it voiced surprise over the claims of an attack on science happening in the negotiations and accused some of the IPCC’s loudest-defending governments of hypocrisy for continuing to expand fossil fuels and not delivering “fair shares” of emissions cuts and finance to the developing world.
“We were really shocked we could not find a common position and then this jarring narrative was being pushed,” the campaigner added.
After divisions hardened in Bonn, Hare said his organisation was approached by “very upset” CAN members from various regions about the stance taken by the network’s international leadership on the issue.
Industry and NGOs lobby to weaken UN carbon credit rules in “coordinated” push
While Climate Home News understands that internal discussions have continued during the summer, including at a CAN leadership meeting in Nairobi in recent days, the campaigner said that CAN International’s endorsement of the recent webinar that directly challenged the “Friends of Science” coalition did not send a reassuring signal.
Some observers said they feared it would inflame tensions over how climate science is defined and utilised for policy purposes, with consequences reaching well beyond Bonn.
In a statement to Climate Home News, Essop said that “at a time when communities are experiencing the most horrific impacts of climate chaos, our collective energy must turn to solutions such as filling the Loss and Damage Fund, the phasing out of fossil fuels led by the Global North, and justice for people who are least responsible for this climate emergency”.
The post As science comes under attack at UN talks, climate movement splits over how to respond appeared first on Climate Home News.
As science comes under attack at UN talks, climate movement splits over how to respond
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