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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

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.

Credit: Amended from Schleussner et al (2024).

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:

Overshoot pathways ragout

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.”

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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.

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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 Kristie Ebi, Dr Jonathan Donges. Prof Debra Roberts, Prof Deliang Chen, Dr Matt Gidden, Dr Annika Högner and Dr Keywan Riahi at a plenary session at the Overshoot Conference.
Prof Kristie Ebi, Dr Jonathan Donges, Prof Debra Roberts, Prof Deliang Chen, Dr Matt Gidden, Dr Annika Högner and Dr Keywan Riahi at a plenary session at the Overshoot Conference. Credit: IIASA

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.

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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.”

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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”.

Delegates attend a poster session at the Overshoot Conference. Credit: IIASA
Delegates attend a poster session at the Overshoot Conference. Credit: IIASA

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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.

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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.”

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DeBriefed 21 November 2025: [COP30 DeBriefed] ‘Mutirão’ text latest; ‘Roadmaps’ explained; COP finish times plotted

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Welcome to Carbon Brief’s DeBriefed. 
An essential guide to the week’s key developments relating to climate change.

This week

Key ‘mutirão’ text emerges

‘MUTIRÃO’ 2.0: After many late nights, but little progress – and a dramatic fire at the COP30 venue – the much-awaited second draft of the summit’s key agreement, called the “mutirão” text, finally dropped this morning. The new mutirão text “calls for efforts to triple adaptation finance” by 2030 and would launch a presidency-led “Belém mission to 1.5C” alongside a voluntary “implementation accelerator”, as well as a series of “dialogues” on trade. It “decides to establish” a two-year work programme on climate finance, including on a key section of the Paris Agreement called Article 9.1, but has a footnote saying this will not “prejudge” how the climate finance goal agreed last year is met.

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A two-week, all-access package designed for those who need much more than headlines.

ROADMAPS TO NOWHERE: The latest draft does not refer to the idea of a “fossil-fuel roadmap”, which is not on the COP30 agenda, but has been pushed by Brazil’s president Luiz Inácio Lula da Silva and a group of parties (see below). A letter to the presidency, seen by Carbon Brief and reportedly backed by at least 29 countries, including Colombia, Germany, Palau, Mexico and the UK, says: “We cannot support an outcome that does not include a roadmap [on fossil fuels].” It also flags the lack of a roadmap on deforestation. The letter asks for a revised text.

PLENARY WHEN: The latest draft of the mutirão text is unlikely to be the last. There is also a set of draft decisions that have not been fully resolved. For instance, this morning, the Brazilian COP presidency floated a draft decision on what it is calling the “Belém gender action plan”, with three brackets versus the 496 brackets in the previous version. At a short, informal stocktaking plenary, COP30 president André Corrêa do Lago invited countries to react to the drafts in a “mutirão” meeting, namely, in the “spirit of cooperation”. But expect all timings to be flexible, as they work to iron out differences in closed-door meetings.

Adaptation COP

TRIPLING TARGET: A new text for the global goal on adaptation dropped alongside the mutirão text this morning, after days of tense negotiations. Crucially, it includes the adoption of some of the indicators, which will be used to track countries’ progress on adaptation. Last week, the African Group and others called for the indicators not to be adopted at COP30 – one of the key expectations ahead of the summit – and, instead, a two-year work programme to further refine them due to concerns around adaptation finance.

INDICATORS: The latest text adopts an annex of 59 of the potential 100 indicators, emphasises that they “do not create new financial obligations or commitments” and decides to establish a two-year “Belém-Addis vision” on adaptation to further refine the indicators. The only remaining bracket within the text is to allow for the addition of the final adaptation finance target from the mutirão – which, currently, “calls for efforts to triple adaptation finance compared to 2025 levels by 2030”.

WHAM BAM: The latest text for another key negotiating stream on the “just transition work programme” (JTWP) “decides to develop a just transition mechanism”. This has been a point of particular contention within negotiations. Civil society developed the concept of the Belém Action Mechanism (BAM) over the past year and the G77 and China, a large group of global-south nations, tabled it within the JTWP in the first week. However, there was pushback from the EU, UK and others, with the former instead proposing an “action plan” as an alternative.

CRITICAL MINERALS: While landing on the inclusion of a mechanism is being welcomed by civil society and others, the latest text removes the reference to critical minerals included in its predecessor. If included, it would be the first time a reference to “critical minerals” is adopted in the JTWP.

Around the COP

  • Turkey will host COP31, while Australia will take on the presidency and lead the negotiations, under a compromise deal reached between the two nations on Thursday, Reuters reported.
  • Brazil set out a plan before COP30 to reform the “action agenda” – which includes 117 “plans to accelerate solutions” outside of the negotiations, covering everything from fossil-fuel phaseout to “sustainable diets for all”. On Wednesday, the presidency rounded off a series of events that have been used to promote this vision.
  • China called for the creation of a “practical roadmap” for delivering climate finance by developed countries, which delegation head Li Gao said would help “prevent further erosion of trust between developed and developing countries”. 
  • An estimated 70,000 people marched in 32C heat in Belém on Saturday, marking the largest COP protest since COP26 in Glasgow.

52

The number of COP30 agenda items that had been agreed by the time DeBriefed was sent to readers.

51

The number of COP30 agenda items not yet agreed.


Latest climate research

  • A five-year drought in Iran and around the Euphrates and Tigris basins “would have been very rare” without human-caused climate change | World Weather Attribution
  • Integrating nature-based solutions into urban planning could reduce daytime temperatures by 2C during hot periods | Nature Cities
  • Warming of the “deep Greenland basin” has exerted “obvious impacts” on the deep waters of the Arctic Ocean | Science Advances

(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)

Captured

cop30-overrun5

This week saw the Brazilian presidency pledge to conclude some of the most controversial issues at COP30 a whole two days early. In the end, no early deal materialised. As the event approaches its official end time later today, with none of the major negotiations finished, this chart serves to remind that COPs have not finished on time for more than two decades.

Spotlight

‘Roadmaps’ explained

This week, Carbon Brief explains the push for new “roadmaps” away from fossil fuels and deforestation at COP30.

Speaking during the world leaders summit in Belém ahead of COP30, Brazilian president Luiz Inácio Lula da Silva said that the world “need[s] roadmaps to justly and strategically reverse deforestation [and] overcome dependence on fossil fuels”.

His words appeared to spark a movement of countries to call for new roadmaps away from fossil fuels and deforestation to feature as key outcomes of this COP – despite not being on the official agenda for the negotiations.

While momentum for each roadmap has grown, they were referenced only as an option in the first version of COP30’s key text, called the “global mutirão” – and in the second version the reference to roadmaps has disappeared entirely.

Below, Carbon Brief explains the origins of each roadmap, how support for them has grown and how they might feature in COP’s final outcome.

Fossil-fuel roadmap

Most people cite Lula’s pre-COP speech as the start of the movement for a fossil-fuel roadmap.

However, an observer close to the process told Carbon Brief that the COP30 presidency had, in fact, been consulting on the possibility of a roadmap months earlier – drawing help from the Beyond Oil and Gas Alliance, a small group of nations who have pledged to phase out all fossil fuels.

While Brazil was the first country to support the fossil-fuel roadmap, it was joined in the first few days of COP by eight Latin American countries that form the Alliance of Latin America and the Caribbean (AILAC) and by the Environmental Integrity Group (EIG), which includes Mexico, Liechtenstein, Monaco, South Korea, Switzerland and Georgia.

The call for a roadmap was also backed by the Alliance of Small Island States (AOSIS), a group of 39 small low-lying island nations.

As momentum grew, the first global mutirão text appeared on Wednesday 19 November. Paragraph 35 of the text listed three options for where a reference to a fossil-fuel roadmap map might be incorporated, including one option for “no text”.

Later that day, ministers and climate envoys from more than 20 countries united for a packed-out press conference, where they called the current reference to the fossil-fuel roadmap “weak”, adding that it must be “strengthened and adopted”.

At the sidelines of the conference, UK climate envoy Rachel Kyte told journalists that around 80 countries now backed the call for a roadmap. (Carbon Brief obtained the list of 82 countries that have expressed their support.)

However, COP30 CEO Ana Toni told a press conference later that day that a “great majority” of country groups they had consulted saw a fossil-fuel roadmap as a “red line”.

In an interview with Carbon Brief, Dr Osama Faqeeha, deputy environment minister for Saudi Arabia, refused to be drawn on whether a fossil-fuel roadmap was a red line, but said:

“I think the issue is the emissions, it’s not the fuel. And our position is that we have to cut emissions regardless.”

The next day, the EU officially threw its weight behind the call for a fossil-fuel roadmap, after initial delay caused by hesitation to join the movement from Italy and Poland, Climate Home News reported.

The EU circulated its own proposal for how a fossil-fuel roadmap could be referenced in the global mutirão text, the publication added.

However, the latest version of the global mutirão text, released today, does not reference a roadmap at all. It has already sparked condemnation from a range of countries and observers.

It is expected that at least one more iteration of the text will emerge before the COP30 presidency attempts to find agreement, which could see a reference to the roadmap reappear.

Deforestation roadmap

While Lula called for roadmaps away from both fossil fuels and deforestation, the latter has received less attention, with one observer joking to Carbon Brief it had become the “sad forgotten cousin”.

A roadmap away from deforestation was originally only backed by Brazil, the EIG and AILAC.

However, the EU became a relatively early backer – announcing its support for a deforestation roadmap before a fossil-fuel roadmap.

The Democratic Republic of the Congo – one of the world’s “megadiverse” nations and one of the countries responsible for the Congo rainforest – has also announced its support. (See Carbon Brief’s list of supporters.)

As with the fossil-fuel roadmap, a reference to a deforestation roadmap appeared in the first iteration of the mutirão text, but has disappeared from the second. It may – or may not – appear in another version of the text before COP30’s finale.

Watch, read, listen

FOREST TALES: In a new video series from Earthday.org and the Pulitzer Centre, three investigative journalists discussed their reporting on deforestation in Brazil and the Democratic Republic of the Congo.

AI IMPACTS: Google CEO, Sundar Pichai, spoke to BBC News about the climate impacts of AI, among other topics.

MISSING DATA: Columnist George Monbiot wrote in the Guardian about the “vast black hole” of climate data in some parts of the world – which he says is a “gift” to climate deniers.

Coming up

Pick of the jobs

DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.

This is an online version of Carbon Brief’s weekly DeBriefed email newsletter. Subscribe for free here.

The post DeBriefed 21 November 2025: [COP30 DeBriefed] ‘Mutirão’ text latest; ‘Roadmaps’ explained; COP finish times plotted appeared first on Carbon Brief.

DeBriefed 21 November 2025: [COP30 DeBriefed] ‘Mutirão’ text latest; ‘Roadmaps’ explained; COP finish times plotted

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Cropped 19 November 2025: COP30 edition

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We handpick and explain the most important stories at the intersection of climate, land, food and nature over the past fortnight.

This is an online version of Carbon Brief’s fortnightly Cropped email newsletter. Subscribe for free here.

Key developments

COP30 nears its end

COP TALK: The COP30 climate summit is entering its final days in Belém – and food, forests and land have all featured across the two weeks of talks. The formal agriculture negotiations track at climate COPs is the Sharm-el-Sheikh joint work on climate action for agriculture and food security (SWJA). Talks, however, came to an abrupt halt last Thursday evening, with countries agreeing to continue discussions on a draft text – with elements ranging from agroecology to precision agriculture – in Bonn next year.

DEFORESTATION ROADMAP: WWF and Greenpeace called for a roadmap at COP30 to end deforestation. There has been a lot of chatter about roadmaps in Belém, with more than 80 countries backing calls for a roadmap for phasing out fossil fuels, the Guardian said. Kirsten Schuijt from WWF told a press conference that a similar plan on ending deforestation should include “real actions and ambition to bend the curve on forest loss”. Writing for Backchannel, Colombia’s environment minister Irene Vélez-Torres said: “We need to see the global north come behind a roadmap – and quickly”. (Carbon Brief’s Daisy Dunne has started tracking the countries in favour, such as Colombia.)

CARBON MARKETS: Elsewhere at the talks, nature-based solutions featured in an early draft text of carbon market negotiations. (Carbon Brief’s Aruna Chandrasekhar took a closer look at some of these references.) In addition, the Brazilian presidency launched a global coalition of “compliance carbon markets” on 7 November, which was endorsed by 18 countries.

BIG AG IN BELÉM: More than 300 industrial agriculture lobbyists attended COP30, according to an investigation by DeSmog and the Guardian. This is a 14% increase on last year, DeSmog reported, and larger than Canada’s entire delegation. One in four agricultural lobbyists attended the talks as part of an official country delegation, the outlet noted. Elsewhere, Unearthed found that the sustainable agriculture pavilion at COP30 was “sponsored by agribiz interests linked to deforestation and anti-conservation lobbying”. Brazilian outlet Agência Pública reported that Brazil placed the “billionaire brothers” who own JBS, the world’s largest beef producer, on a “VIP list” at the summit.

TRACKING PROGRESS: A UN report found that while progress has been made towards a global pledge to cut methane emissions by 30% by 2030, emissions of the potent greenhouse gas continue to rise. The report said agricultural methane is projected to increase by 4-8% by 2030, but could instead reduce by 8% with methane-reduction measures. Elsewhere, a report covered by Down to Earth found that countries need more than 1bn hectares of land, “an area larger than Australia”, to meet carbon removal pledges.

Indigenous presence in Belém

QUESTIONED PARTICIPATION: Ahead of COP30, Brazil’s presidency had expected the arrival of 3,000 Indigenous peoples in Belém. Indigenous peoples from the Amazon were at COP30 “in greater numbers than ever before”, with 900 representatives granted access to the negotiations, the New York Times reported. However, only four people from Brazil’s afro-descendant Quilombolas communities held such accreditation, Climate Home News and InfoAmazonia reported. A boat journey that took 62 Indigenous representatives across the Amazon river to attend the COP30 was covered by Folha de São Paulo, Reuters and El País.

VARIED DEMANDS: Indigenous leaders arrived in Belém with a variety of demands, including the inclusion of their land rights within countries’ climate plans, the New York Times added. It wrote that land demarcation “would provide legal protection against incursion by loggers, farmers, miners and ranchers”. Half of the group that sailed across the Amazon river were youths that brought demands from Amazon peoples to the climate summit, El País reported. A small Indigenous group from Cambodia attended COP30 to combat climate disinformation and call for ensuring Indigenous rights in forest projects, Kiri Post reported.

FROM BLOCKADES TO THE STREETS: During the first week of COP30, Indigenous protesters blocked the entrance of the conference and clashed with police officers when demanding climate action and forest protection, Reuters reported. Tens of thousands of protesters, including Indigenous peoples, took to the streets of Belém on Saturday to demand climate justice and hold a funeral for fossil fuels, Mongabay and the Guardian reported.

News and views

AGRI DISASTERS: Disasters have driven $3.26tn in agricultural losses worldwide over the past 33 years, amounting to around 4% of global agricultural GDP, according to a new report from the UN Food and Agriculture Organization. The report assessed how disasters – including droughts, floods, pests and marine heatwaves – are disrupting food production, livelihoods and nutrition. It found that Asia saw nearly half of global losses, while Africa recorded the highest proportional impacts, losing 7.4% of its agricultural GDP.

WATER ‘CATASTROPHE’: Iran is facing “nationwide catastrophe” due to “worsening droughts, record-low rainfall and decades of mismanaged water resources”, Newsweek reported. According to Al Jazeera, the country is facing its sixth consecutive drought year, following high summertime temperatures. The outlet added: “Iran spends 90% of its water on low-yield agriculture in a pursuit of self-sufficiency that exacerbates drought.” BBC News reported that authorities in the country have “sprayed clouds” with salts to “induce rain, in an attempt to combat” the worsening drought.

TRUMP THREAT: The Trump administration will allow oil and gas drilling in Alaska’s North Slope – home to “some of the most important wildlife habitat in the Arctic” – the New York Times reported. The announcement reverses a decision made during the Biden administration to restrict development in half of the National Petroleum Reserve in Alaska, the newspaper said. Separately, Reuters reported that the US Department of Agriculture directed its staff to identify grants for termination at the start of Trump’s second administration by searching for “words and phrases related to diversity and climate change”.

FIELDS FLATTENED: Thousands of acres of sugarcane plantations in the Philippines’ Visayas islands were destroyed by Typhoon Tino earlier this month, the Philippine Star reported. Damages to the country’s sugar industry have been estimated at 1.2bn Philippine dollars (£15.5m), it added. Sugar regulator administrator Pablo Luis Azcona told the Manila Times: “We have seen entire fields decimated by Tino, especially in the fourth and fifth districts of Negros Occidental, where harvestable canes were flattened and flooded. We can only hope that these fields will be able to recover.”

FARMS AND TREES: EU countries and the European parliament have provisionally agreed on an “overhaul” of farming subsidies, Reuters reported. The changes would “exempt smaller farmers from baseline requirements tying their subsidies to efforts to protect the environment” and increase their potential payments, the newswire said. Campaigners told Reuters that these changes would make farmers more vulnerable to climate change. Elsewhere, Bloomberg said EU countries are “pushing for a one-year delay” of the bloc’s planned anti-deforestation law – “seeking more time to comply” with the law compared to different proposed changes from the European Commission.

ANOTHER FUND: Brazil is mulling over the creation of a new fund for preserving different biomes, such as the Cerrado, inspired by the Amazon Fund, Folha de São Paulo reported. Discussions are underway between Brazil’s president and the Brazilian Development Bank (BNDES), according to the newspaper. Separately, the Washington Post reported on how Brazil’s efforts to position itself as a climate leader at COP30 has been undermined by Lula’s approval of new oil drilling in the Amazon and elimination of environmental permits.

Spotlight

Key COP30 pledges

This week, Carbon Brief outlines four of the biggest COP30 initiatives for food, land and forests.

Tropical Forest Forever Facility

Brazil’s tropical forest fund – arguably the biggest forest announcement from this year’s climate talks – was hailed by WWF and others as a “gamechanger” upon its launch almost two weeks ago. Since then, the fund has raised $5.5bn – far below even Brazil’s reduced target of $10bn by next year.

Norway, Brazil, Indonesia, Portugal, France and the Netherlands have all committed to pay into the fund, while Germany has said it will announce its contribution soon. The UK and China, on the other hand, do not plan to pay in.

Intergovernmental Land Tenure Commitment

This new “landmark” commitment aimed to “recognise and strengthen” the land rights on 160m hectares of Indigenous peoples and local community land by 2030, according to the Forest & Climate Leaders’ Partnership.

It has been backed by 14 countries, including Brazil, Colombia, the Democratic Republic of the Congo, Indonesia and the UK.

Relatedly, $1.8bn has been pledged from public and private funding to help secure land rights for Indigenous peoples, local communities and Afro-descendent communities in forests and other ecosystems.

Belém Declaration on Hunger, Poverty and People-Centered Climate Action

Signatories of this declaration committed to a number of actions aiming to address the “unequal distribution of climate impacts”, including expanding social protection systems and supporting climate adaptation for small farmers.

It was adopted by 43 countries and the EU. A German minister described it as a “pioneering step in linking climate action, social protection and food security”.

Belém 4X

This initiative aimed to gather high-level support to quadruple the production and use of “sustainable fuels”, such as hydrogen and biofuels, by 2035.

It was launched by Brazil and has been backed by 23 countries so far, including Canada, Italy, Japan and the Netherlands.

However, the pledge has been “rejected” by some NGOs, including Climate Action Network and Greenpeace, who criticised the environmental impact of biofuels.

Watch, read, listen

FOOD CHAT: Bite the Talk, a podcast by the Global Alliance for Improved Nutrition, explored the “critical intersection of climate change and nutrition”.

TRUE SAVIOURS: On Instagram, the Washington Post published a list of 50 plant and animal species that “have enriched and even saved human lives”.

NO MORE WASTE: A comment piece by the founder of London’s Community Kitchen in the Independent addressed the relevance of food waste to the climate agenda.

FOREST FRENZY: The Financial Times spoke to Amazon climate scientist Prof Carlos Nobre about tipping points and his “zeal for saving the rainforest”.

New science

  • Floods led to a 4.3% global reduction in annual rice yield over 1980-2015, with crop losses accelerating after the year 2000 – “coinciding with a climate change-induced uptick in the frequency and severity” of floods | Science Advances
  • Loss of African montane forests led to local “microclimate” warming of 2.0-5.6C over 2003-22, diminishing the “temperature-buffering capacity” of the forests | Communications Earth & Environment
  • “Prolonged” drought is linked to an increase in conflict between humans and wildlife – especially carnivores | Science Advances

In the diary

Cropped is researched and written by Dr Giuliana Viglione, Aruna Chandrasekhar, Daisy Dunne, Orla Dwyer and Yanine Quiroz.  Ayesha Tandon also contributed to this issue. Please send tips and feedback to cropped@carbonbrief.org

The post Cropped 19 November 2025: COP30 edition appeared first on Carbon Brief.

Cropped 19 November 2025: COP30 edition

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COP30: Carbon Brief’s second ‘ask us anything’ webinar

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As COP30 reaches its midway point in the Brazilian city of Belém, Carbon Brief has hosted its second “ask us anything” webinar to exclusively answer questions submitted by holders of the Insider Pass.

The webinar kicked off with an overview of where the negotiations are on Day 8, plus what it was like to be among the 70,000-strong “people’s march” on Saturday.

At present, there are 44 agreed texts at COP30, with many negotiating streams remaining highly contested, as shown by Carbon Brief’s live text tracker.

Topics discussed during the webinar included the potential of a “cover text” at COP30, plus updates on negotiations such as the global goal on adaptation and the just-transition work programme.

Journalists also answered questions on the potential for a “fossil-fuel phaseout roadmap”, the impact of finance – including the Baku to Belém roadmap, which was released the week before COP30 – and Article 6.

The webinar was moderated by Carbon Brief’s director and editor, Leo Hickman, and featured six of our journalists – half of them on the ground in Belém – covering all elements of the summit:

  • Dr Simon Evans – deputy editor and senior policy editor
  • Daisy Dunne – associate editor
  • Josh Gabbatiss – policy correspondent
  • Orla Dwyer – food, land and nature reporter
  • Aruna Chandrasekhar – land, food systems and nature journalist
  • Molly Lempriere – policy section editor

A recording of the webinar (below) is now available to watch on YouTube.

Watch Carbon Brief’s first COP30 “ask us anything” webinar here.

The post COP30: Carbon Brief’s second ‘ask us anything’ webinar appeared first on Carbon Brief.

COP30: Carbon Brief’s second ‘ask us anything’ webinar

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