The global shift towards a clean-energy system is much more than just a technological switch – it is a profound transformation of markets, industries and societal behaviours.
This complex undertaking is often characterised by “non-linearity” and “feedback loops”, where small changes can go on to have disproportionately large impacts and where seemingly straightforward paths encounter unexpected roadblocks.
Interventions can be self-amplifying – leading to runaway change, or they can be self-defeating – when progress seems impossible to attain.
Our new policy brief sheds light on these intricate dynamics, which can be overlooked when governments use analytical frameworks based on standard economic thinking.
The brief sets out the most common archetypes of system change and behaviour, as well as the underlying feedback loops that drive them, with the aim of helping policymakers to understand the recurring patterns that can either accelerate or impede progress.
Governments that can recognise these patterns – as well as the ways they can be harnessed or sidestepped – are likely to be better equipped to manage structural change.
This article delves into three key examples from the policy brief, exploring how they are influencing the energy transition and what lessons can be drawn for effective policymaking.
Reinforcing feedback loops
At the heart of the energy transition lies a powerful engine: the reinforcing feedback loops inherent in the development and diffusion of many clean-energy technologies.
This virtuous cycle operates through several mechanisms.
First, “learning by doing”, which means that as more units of a technology, such as solar panels or wind turbines, are produced and deployed, manufacturers and developers become more efficient, processes are refined and costs fall.
Second, economies of scale kick in: as production volumes increase, unit costs decrease due to efficiencies in manufacturing and more developed supply chains.
Finally, wider deployment can trigger network effects and the emergence of complementary innovations. This means that as the adoption of a given technology grows, it can foster an ecosystem of supporting infrastructure, skilled labour and supporting technologies, which can further boost its attractiveness and viability.
Together, these three elements create a powerful reinforcing loop: initial investment drives innovation and cost reduction, which spurs increased demand, attracting further investment.
Solar photovoltaics (PV) and wind turbines are prime examples of this dynamic.
The astonishing growth of solar offers a particularly vivid illustration of the way in which reinforcing feedback loops can blindside experts and policymakers alike.
Solar growth has far exceeded projections made in the early 2000s. Indeed, the world’s actual installed capacity in 2020 was over 700 gigawatts (GW), more than ten times the level expected in outlooks published in 2006, as shown in the figure below.
Global solar deployment has exceeded expectations due to disparate trends and drivers in individual markets that, together, all point in the same direction. China, for instance, met its 2030 target for wind and solar capacity six years ahead of schedule in 2024.
Batteries are also riding this wave, with costs plummeting by around 85% over the past decade as deployment, particularly in road transport, scales up.
However, not all clean-energy technologies benefit from this self-amplifying pattern.
Nuclear power and hydropower, for example, have historically not shown the same rapid cost declines, due to their large, complex and site-specific nature. This contrasts with the smaller, modular and replicable characteristics of technologies, such as solar PV.
This does not negate the potential role of such technologies, but it does mean that they are less likely to see disruptive, exponential and self-reinforcing growth.
There are a number of potential conclusions for policymakers.
Early in the transition, interventions such as feed-in tariffs and public procurement were crucial in kick-starting these reinforcing feedbacks for solar and wind.
As these technologies mature and become cost-competitive, the focus shifts to removing other barriers, such as streamlining permitting processes, investing in grid expansion and reforming markets so they are better able to integrate variable renewable output.
These same principles could now be applied to newly emergent clean-energy technologies. Policies that directly nurture these reinforcing loops, such as deployment subsidies and clean technology mandates, can be expected to be most effective in the initial stages.
Turning again to the example of solar energy, while such initial efforts appeared to be expensive, they paid off over time by unlocking future cost reductions and, thus, kick-starting the self-amplifying feedback loops that are now driving further progress.
This contrasts with the idea that carbon pricing is necessarily the most efficient policy for decarbonisation. It may well be helpful, but as it will not drive rapid early technology adoption, it is less likely to have a self-amplifying effect in the initial stages of the transition.
Renewable ‘cannibalisation’
While the growth of renewable energy is the driving force of the energy transition, another system dynamic, termed “renewable cannibalisation“, can act as a dampening feedback loop. This can potentially slow progress long before full decarbonisation is achieved
This cannibalisation process results in variable renewable energy (VRE) sources, such as solar and wind, receiving decreasing prices for the electricity they generate.
Essentially, the more solar and wind capacity that is connected to the grid, the more they undermine their own revenue. This happens through three main channels.
First, the merit order effect, whereby solar and wind, which have very low operating costs, push more expensive fossil-fuel generators out of the market when supply is abundant.
In markets with marginal pricing, this leads to lower wholesale electricity prices during periods of high renewable output. While this cuts prices for consumers – at least in the short term – these lower prices also reduce revenues for renewable generators, potentially undermining the economic case for further investment.
For example, in California, solar power unit revenues fell by $1.30 per megawatt hour (MWh) for each percentage point increase in solar penetration between 2013 and 2017.
Second, price volatility, where uncertainty over future trends in the generation mix and the balance between supply and demand can make long-term revenues difficult to predict.
This increased uncertainty can raise the cost of capital for new renewable projects, again acting as a brake on investment
The UK, for example, experienced this before the introduction of “contracts for difference” (CfDs), which helped stabilise revenue expectations for renewable developers.
Third, volume risk, where rising VRE capacity increases the likelihood of more frequent curtailment – periods when renewable generation exceeds demand or grid capacity, forcing generators to scale back output and lose potential revenue.
Curtailment in itself is nothing new, but the scale and frequency is changing. Recent analysis by University College London suggests that without significant flexibility or storage, UK renewable generation could exceed demand for more than 50% of the time by 2030.
The analysis found that installed wind and solar capacity is set to surge beyond current levels of electricity demand, as illustrated in the figure below, finding that this could “deter investment” in new projects if no action is taken to address the problem.
These dampening feedback loops illustrate a classic “limits to success” scenario. The very success of renewables, if unmanaged, can create conditions that hinder their continued expansion.
The policy implications here are nuanced. One solution is CfDs, which offer renewable generators a fixed price and have been effective in many countries at mitigating the merit order effect and price volatility, thus maintaining investment.
However, as VRE penetration becomes very high and surplus generation becomes a regular occurrence, other solutions are likely to be needed. This is because existing CfD designs often include clauses that stop payments when market prices drop below zero.
As a result, alternative CfD designs, guaranteeing revenues based on installed capacity or potential – rather than actual – electricity generation might be considered, for example, even though these have other drawbacks.
More fundamentally, our research suggests the solution to this challenge lies in fostering the co-evolution of renewables with technologies such as energy storage and green hydrogen production. These can absorb surplus generation and turn a problem into an opportunity.
Whereas, traditionally, it might be assumed that the market on its own can optimally allocate risk, research suggests that a redesign of market structures may be needed to enable investment and fully realise the cost-saving opportunities of the new technologies.
This is one of several sets of feedbacks discussed in a separate new report published today, looking at the power sector transition in China.
The power of connection
The energy transition is not a series of isolated changes in different sectors. Instead, it is an interconnected system, where progress in one area can catalyse shifts elsewhere. Shared technologies can create reinforcing feedbacks that accelerate decarbonisation across multiple fronts, generating cross-sector synergies.
The relationship between clean power and transport electrification is a powerful example of this. As batteries are deployed at scale in electric vehicles (EVs), their costs fall, enabling ever-wider deployment and further cost declines, as shown in the chart below.
This is due to the learning-by-doing and economies-of-scale feedbacks discussed above.
This cost reduction then makes batteries more viable for grid-scale energy storage, which, in tur, helps integrate more low-cost VRE into the power system.
Cheaper, cleaner electricity then further incentivises the electrification of transport, as well as heating and light industry. This increased electrification boosts demand for renewable power, driving further deployment and cost reductions in solar and wind. It also expands the potential for demand-side response, where consumers adjust their electricity use to help balance the grid.
A similar dynamic is anticipated for “green” hydrogen. As deployment in one anchor sector – perhaps fertilisers or refining – drives down the cost of electrolysers, it makes green hydrogen more competitive for other applications, such as shipping or even long-duration energy storage in the power sector.
Each sector’s adoption of green hydrogen contributes to the shared learning and cost reduction, benefiting all.
The policy implications of these cross-sector synergies could be significant. Their existence suggests, for example, that there is no need to wait for decarbonisation of the power sector to advance further, before beginning the electrification of transport, heating or industry.
This is in contrast to the argument that transport should only be electrified after cutting power sector emissions, since increased EV charging will drive up demand for gas- or coal-fired generation.
While there will be a marginal increase in emissions from plugging a new EV into the power grid, the insights described in our brief imply that it is still likely to be more effective to pursue the transition away from fossil fuels in multiple sectors in parallel, because it can activate beneficial cross-sector feedback loops that are greater than the sum of their parts.
As such, our research suggests that policymakers hoping to take advantage of cross-sector synergies could aim to deliberately strengthen technological linkages between different parts of the energy system. Examples include electricity tariffs and market structures that reward “smart” EV charging and vehicle-to-grid (V2G) services, encouraging industrial participation in demand-side response and promoting integrated home energy systems. These interactions can amplify the benefits of early investment in the transition.
Policy insights from system dynamics
Archetypes such as the self-reinforcing growth of clean technologies, the potential for renewable cannibalisation, the accelerating power of cross-sector synergies and seven others described in our new report paint a picture of a transition that is far from linear. Instead, we find that it is governed by complex interdependencies and feedback loops.
Consequently, our research suggests that policymakers will be much better equipped to manage and steer the transition, if they adopt a systems thinking approach.
Recognising these recurring patterns allows for the design of more robust and effective policies that anticipate challenges and leverage opportunities.
For instance, understanding the power of reinforcing feedback loops in technology diffusion underscores the value of early-stage support for nascent clean-energy technologies.
Conversely, anticipating the dampening effects of renewable cannibalisation highlights the likely benefits of combining renewable buildout with evolving market designs and strategic investments in flexibility solutions, such as storage and demand-side response.
Policymakers that understand and work with these dynamics are likely to be in a better position to spark self-amplifying changes – achieving maximum value for minimum effort – and to avoid self-defeating interventions that go nowhere.
The post Guest post: How ‘feedback loops’ and ‘non-linear thinking’ can inform climate policy appeared first on Carbon Brief.
Guest post: How ‘feedback loops’ and ‘non-linear thinking’ can inform climate policy
Climate Change
From Belém to Antalya – gains, gaps and challenges for a new Just Transition Mechanism
Could a new mechanism to help countries transition to a cleaner, safer and fairer world be one of the main deliverables from the COP31 climate summit in Türkiye this November? Civil society groups – which played a key role in winning last year’s agreement in Brazil to set up a mechanism – want to see it come to life in Antalya and take shape in 2027.
The concept of a “just transition” has gained momentum and widespread support in recent years. It recognises that countries have varying levels of responsibility for planet-heating emissions and unequal resources to adapt to the impacts of global warming and move away from fossil fuels.
In July, UN Secretary General António Guterres told the High-Level Political Forum in New York: “We need to support the countries, communities and workers that depend on fossil fuels throughout the transition.” While few would dispute that need, governments at the UN climate talks are still working out how to respond to it with concrete action.
With discussions set to produce a decision making the mechanism a reality at COP31, observers want to ensure the new mechanism is more than just a talking shop.
Here’s what’s at stake in the just transition negotiations before and at COP31:
What has been agreed on the mechanism so far?
At the mid-year climate negotiations in Bonn, just transition was one of the few key issues on which governments reached a consensus, including on how to review the progress of the Just Transition Work Programme (JTWP) – a process that led to agreement on a mechanism last year at COP30 in Belém, Brazil.
Set up in 2022 and launched a year later, the aim of the JTWP is to discuss how to achieve a green economic and social shift that is fair, from the global down to the local level. Its accompanying mechanism will be tasked with strengthening international cooperation, technical support, capacity-building and knowledge-sharing to enable societies to become low-carbon and climate-resilient in a way that does not harm people and shares the benefits.
To phase out fossil fuels, developing countries need exit route from “debt trap”
Anabella Rosemberg, senior advisor on just transition with Climate Action Network (CAN) International, told Climate Home News that the most important outcome in Bonn was an informal document laying out various options for establishing the new mechanism.
However, this leaves a lot still to be worked out and the preliminary discussions at Bonn were not enough on their own to ensure the operationalisation of the mechanism at COP31, as planned.
“In the months ahead of COP31, this issue should be a priority for the COP31 presidencies – both Türkiye and Australia,” said Camila Mercure, climate policy coordinator at the Environment and Natural Resources Foundation (FARN), an Argentinian NGO, adding this would help secure more space for debate in the lead-up to and during the annual summit.
So far, an informal workshop for governments and NGOs to exchange views on the JTWP and the mechanism, and to push things forward has been organised from September 30 to October 2 in Sydney.
How will the review of the Just Transition Work Programme affect the mechanism?
One task for COP31 is to review the efficiency and effectiveness of the JTWP so far and to decide whether and how it will continue.
For Laura Restrepo Alameda, advocacy officer at Climate Action Network Latin America (CANLA), the main positive aspect is that it will include a mapping of instruments, initiatives and processes relevant to just transitions under the UN climate convention, the Paris Agreement and among other UN entities. “It’s a resource that will enable us to assess the complementarity and coherence of the various tools available to support the implementation of a [just transition] mechanism,” she told Climate Home News.
Not everyone wants the JTWP review and the work to launch a mechanism to feed into one another. Russia, Arab nations and a group of large emerging nations pushed for them to be separate – which they believe would make it easier to limit the scope of the mechanism – while the African Group defended joint work between the two processes.
According to Anthony Dane of Southern Transitions, a South Africa-based “think and do-tank”, governments also have varying concerns around the mapping exercise, which is being carried out by the UN climate change secretariat.
He noted in a recent webinar that some want to use it as a basis to argue that a lot is already being done on just transition and so the new mechanism does not need to offer much more, while others are preparing to argue the opposite, highlighting a lack of international cooperation and support.
For Dane, the mapping exercise also raises the bigger question of how to define the scope of “just transition” within the UN climate talks.
So far, richer countries have favoured a narrower view that focuses on phasing out fossil fuels, while developing countries have pushed for a broader “whole of economy, whole of society” approach that encompasses issues like green industrialisation and sustainable development.
Russia and some other high-emitting nations do not want the JTWP or its mechanism to become a tool for imposing new green trade restrictions, while the European Union has rejected attempts to use it as a forum to dispute its new carbon levy on imports. These debates are set to rumble on.
What will the mechanism do and when will it start?
In Bonn, countries discussed the design features of the mechanism – that is, the elements, governance arrangements, structures and functions it should have. The outcome was an informal preliminary note compiling a range of views and possible options.
While most country negotiating groups welcomed the document as a basis for further talks, Arab countries said it did not reflect their priorities, with Saudi Arabia insisting it had no formal status.
“The mechanism must contribute to international cooperation between countries, serve as a guide, support countries so that they can develop just transition strategies, and act as a channel for accessing funding to implement projects within their territories,” said Mercure of FARN.
But exactly what the mechanism should cover, and what it should not, remain a contentious subject for governments.
For example, the Like-Minded Developing Countries – a bloc of more than 20 low- and middle-income nations including China and India – and the Arab Group appear keen to avoid any targets, requirements or conditionalities being imposed on them with regard to transitioning away from fossil fuels (TAFF).
That contrasts with some Latin American and small island states that would like to see the mechanism used as a way of furthering global commitments already made in 2023 on TAFF and tripling renewable energy by 2030.
Developed countries, for their part, do not want the mechanism to put too much responsibility on them to provide finance and other forms of cooperation.
Some experts Climate Home News spoke to, meanwhile, called for the mechanism to lay out actions for different sectors – not just energy but also others like agriculture and heavy industries.
Sandeep Pai, senior lead for international energy transitions at Duke University, said the mechanism should focus on at least eight to ten high-emitting sectors, addressing how to support workers through the transition to cleaner ways of operating. But, he noted “talking about sectors was always an issue at the negotiations”.
Another issue important to civil society groups is that justice should be embedded in the process to operationalise what they have informally dubbed the BAM (short for the Belém Action Mechanism or, more recently, the Belém Antalya Mechanism).
“The key milestone between now and COP31 must be to define a structure for the BAM with clear governance, coordination and the inclusion of civil society,” said CANLA’s Restrepo Alameda. The network, which represents hundreds of NGOs, is calling for groups that are likely to be hit hard by the transition, such as workers and Indigenous peoples, to have a seat at the table.
Given the short time-frame until a decision to operationalise the mechanism is due to be agreed and adopted at COP31, experts say all these thorny issues are unlikely to be ironed out by then and further discussions may be needed to refine the form and functions of the new body.
CAN’s Rosemberg told Climate Home News that “an ambitious outcome” at COP31 would be to establish the mechanism with its key functions and modalities in Antalya, while setting up a transitional committee to speed up technical work and ensure the BAM is fully operational by COP32 in Ethiopia in 2027.
What is needed on the ground for a just transition?
The top-down nature of decisions taken at COPs generally do not reflect the specific situations of individual countries and communities on the ground – and this is particularly so when it comes to just transition.
Pai of Duke University contrasted India – where much of the transition will be about moving away from coal mining and coal-fired power stations – with countries that use relatively few fossil fuels like Costa Rica and will need to implement a very different set of changes.
He added that each country must define what a “just transition” means to them, according to their contexts and needs: is it about using less oil and gas, promoting green steel-making and lower-emitting buildings, or transforming some other high-carbon activity? The next step is to establish government bodies and policies to plan and drive the transition.
COP30: Spain’s unions say just transition means renewing communities beyond jobs
“Global and broad declarations on a [just transition] mechanism are a good signal,” said Pai. “But we would be fooling ourselves if we think that just because something is getting declared, it will be implemented.”
When it comes to tackling dependence on coal, for example, Pai noted the difficulty of shutting down coal mines and replacing their role in local economies that tend to be heavily reliant on the industry for both jobs and revenues. According to the International Energy Agency, 3.1 million of the 7.8 million people working in coal-related activities in 2022 were employed in coal mining.
Why is finance the elephant in the room?
Finance – and finding more of it for climate action – has always been a bone of contention between developed and developing countries in the UN climate process, cropping up time and time again across negotiating streams, whether it’s the new goal for tripling resources for adaptation or filling the loss and damage fund.
In the corridors at Bonn, observers told Climate Home News that, for just transition, the discussions on the topic did not centre on setting up a new dedicated fund, but rather touched on how the mechanism could better connect available financial resources with just transition initiatives in countries.
The informal note on the new mechanism includes mobilising and facilitating “grant-based and non-debt-inducing finance” and channelling finance through North-South and other multilateral partnerships. It is unclear whether finance will be included in the final COP31 decision on the BAM. CAN’s Rosemberg has suggested a resource mobilisation taskforce could be set up to start identifying sources of funding.
An analysis by the Organisation for Economic Co-operation and Development (OECD) shows that, during the first year after mass layoffs, workers losing their jobs in energy-intensive industries – such as power supply, heavy manufacturing and transport – lose an average of 58% of their income, compared with 52% experienced in other sectors.
Pai flagged two challenges when it comes to funding just transitions: many large financial institutions don’t want to invest in low and middle-income countries because of their high-risk profile; and developing countries often lack a well-prepared pipeline of investable projects.
The Just Energy Transition Partnerships (JETPs) launched earlier this decade were an effort to overcome these barriers. The donor-backed initiatives, outside the UN climate process, mobilised billions of dollars from the public and private sectors to help several emerging economies, including South Africa and Indonesia, finance the transition to clean energy in an economically and socially fair manner.
But the JETPs have run up against some difficulties, such as Jakarta abandoning its plan to shut down a major coal plant early, which was a key part of the original deal.
Indonesia’s failing Just Energy Transition Partnership is a cautionary tale
With UN climate negotiations on finance seeing positions harden between developed and developing nations as donor governments struggle to meet existing targets, some observers believe talks on funding for just transition are unlikely to produce quick results in the form of hard dollars any time soon.
“Many of those who are asking for money don’t know what they’re asking for, and those who have the money don’t want to give. You can write a paragraph about finance [in the negotiations] but this fundamental reality will not change,” said Pai.
The post From Belém to Antalya – gains, gaps and challenges for a new Just Transition Mechanism appeared first on Climate Home News.
From Belém to Antalya – gains, gaps and challenges for a new Just Transition Mechanism
KOROR, PALAU, Wednesday 2 September 2026 — The new global heating projection by the United Nations Environment Programme (UNEP) has laid bare the dire realities of inevitable climate disaster, loss and damage for the Pacific and Australia in a 1.8°C world, with Greenpeace warning ‘we are now in bloody dangerous territory’, and must do everything possible to return warming to 1.5°C.
The report, Limiting Overshoot – Navigating exceedance of 1.5°C and pathways towards return, released as world leaders meet at this year’s Pacific Islands Forum in Palau, highlights the urgency of the climate crisis, the greatest security threat facing the Pacific. It comes as fracked gas from the Beetaloo Basin, one of Australia’s biggest climate bombs, began flowing for the first time.
Australia is the biggest polluter of all Pacific Islands Forum member states, far exceeding all other forum members combined. Greenpeace is calling on Prime Minister Anthony Albanese to centre Pacific priorities at the Forum, and walk the talk on climate solutions as a genuine family member of the Pacific.
Speaking from Palau, Shiva Gounden, Head of Pacific at Greenpeace Australia Pacific, said: “The latest UNEP report has printed in black and white that fossil fuel-hungry nations have overstepped, overshot and overindulged at the expense of Pacific lives, livelihoods, cultures and communities. This year’s Pacific Islands Forum has made it more apparent than ever that climate change is the region’s greatest security threat, and we cannot waste time on geopolitical power games when our world is sinking beneath our feet.
“As a person from the Pacific, I know our communities will not quietly accept these dire warnings of climate overshoot as our fate; we are already living and fiercely resisting this reality every single day. With every increment of warming, our lands, our livelihoods, and our island homes are threatened, but the Pacific’s resolve only grows stronger. We draw strength from our ocean and those who walked before us; our people are the protectors of the frontlines of climate change and the beacons of climate justice.
“By harnessing the natural power of our sun, winds, and seas through a rapid transition to renewable energy, and uniting in true global collaboration, we can steer back to 1.5°C – this is our moral, legal, and scientific imperative. A Fossil Fuel Free Pacific can breathe life back into the lungs of our islands.”
Also in Palau, Dr Simon Bradshaw, COP31 Lead and climate expert at Greenpeace Australia Pacific, said: “The UN report is warning that we are now in bloody dangerous territory. It lays bare the deadly consequences of reckless fossil fuel expansion, and a failure to listen to Pacific voices and to the decades of emphatic scientific warnings.
“It is a damning indictment of government climate inaction and negligence, coming just days after fracked gas from the Beetaloo Basin started flowing and Woodside’s disastrous Browse gas mega project undergoes Federal decision — two carbon bombs that would lock in decades of dangerous climate pollution and push us past the point of no return.
“Every new fossil fuel project pushes us closer to dangerous and irreversible tipping points in the climate system, with almost unimaginable consequences for the safety and security of communities in the Pacific, Australia and around the world.
“The task now is to minimise the magnitude, duration and consequences of any temperature overshoot. A pathway back to 1.5°C is possible but this pathway cannot be paved by fossil fuels.
“Accelerating the shift from fossil fuels to renewable energy, and working with our big energy partners across Asia to decarbonise together, is not only the path back from the climate brink, but also the key to our energy security and our future prosperity.”
Also in Palau, Vishal Prasad, Director of Pacific Islands Students Fighting Climate Change, said: “This report is terrifying for the young people of the Pacific. We know what 1.5, and what anything beyond it, means for our future, our families, our culture and our environment. 1.5 to stay alive has never been just slogan. It is our reality.
“The International Court of Justice has made it clear: keeping to 1.5 is not a choice, it is a legal obligation. Every new fossil fuel project drives us further from it. So we are not asking for your goodwill. We are not begging you. We are telling you what international law requires of you: end fossil fuel expansion. No new coal, no new oil, no new gas. Your corporate profits cannot be allowed to extinguish our future.”
—ENDS—
Greenpeace Australia Pacific has delegates from the Pacific and Australia at the PIFLM in Palau available for interview
Headshots can be found here
Media contact: Kimberley Bernard in Palau on +61407 581 404 or kbernard@greenpeace.org
‘Bloody dangerous territory’: UN report an indictment of govt climate inaction
Governments must slash emissions further and faster, and keep every climate promise they have made for the planet to be able to return to 1.5C of warming by the end of the century after an inevitable overshoot, a group of prominent climate scientists has said.
In a flagship new report sketching out a way not to lose the most ambitious Paris Agreement goal, the scientists said that global temperatures need to peak at no higher than 1.8C above pre-industrial levels to give the world “a fighting chance” to reverse course. They added that plans to suck carbon dioxide out of the atmosphere can only play a limited role in this effort and cannot substitute for emissions cuts.
A return to the 1.5C warming limit will only be reached in an optimistic scenario that sees governments turn their full national climate plans – known as NDCs – into reality and meet their additional, more ambitious targets to reach net zero emissions, said the report published by the UN Environment Programme (UNEP).
Actual government policy is far off that track. Current measures to cut emissions that are funded and in force put the world on course for around 2.8C of warming by 2100, UNEP has previously found.
Joeri Rogelj, professor of climate science and policy at Imperial College London and one of the report’s authors, said it is necessary to keep the temperature peak as low as possible as there are limits to how fast the world can reverse global warming.
That is because the scale of carbon dioxide removal (CDR) interventions that can be implemented sustainably and in a just way will otherwise not be sufficient and some measures, such as tree-planting or forest management, will be less effective at higher temperatures, he added.
Commenting on the report, UN Secretary-General António Guterres called for the 1.5C overshoot to be “as small and short as possible”. This, he added, “demands an overshoot of ambition”, involving accelerating the phaseout of fossil fuels and pursuing the renewables revolution, slashing methane pollution, and protecting land, forest and oceans.
“Governments must over-deliver on national climate plans, net-zero commitments, and beyond,” he urged in a video message. “The fight for 1.5 degrees is the fight for humanity.”
Overshoot, peak and decline
The report comes out nearly a year after the UN conceded for the first time that it is inevitable that global warming will exceed 1.5C temporarily and the world should focus on making that overshoot as small and short as possible.
UNEP’s Executive Director Inger Andersen told journalists that 1.5C remains the key goal, but “we now need a different approach from above”, while stepping up efforts to adapt to a warming world.
“A return to 1.5C is not assured,” she added. “But limiting the magnitude, duration and consequences of overshoot, while preserving the possibility of bringing temperatures back down, is the best remaining option to protect vulnerable people, reduce losses and secure a livable future for all.”
Battle over cleaning up shipping set to resume at London talks
Scientists warn in the report that warming above 1.5C should not be seen as safe or acceptable. Climate risks above that threshold intensify with every additional fraction of a degree of warming, they said. The report paints a grim picture of expected climate impacts: glaciers could lose more than a quarter of their remaining mass by 2100 and global food production could fall by as much as 14% by 2050 without effective adaptation.
Some small island developing states and low-lying coastal cities could be partially or completely submerged, while damaged ecosystems could further accelerate climate change.
“This report is a ‘fork in the road’ moment for the planet,” said Surangel Whipps, Jr., president of the Pacific island nation of Palau. “It is a further glimpse into a perilous future that has already arrived. To continue to have a fighting chance, calls for greater ambition are no longer enough – we need to see an urgent and unprecedented increase in political will and investment in a climate-safe future.”
Cut emissions first, remove carbon after
The authors call for a three-phase approach to bringing temperatures back down: an “immediate response” of deep and rapid emissions cuts and urgent protection for the most vulnerable as warming approaches and passes 1.5C; a “coping and containment” phase focused on reaching net-zero emissions and building resilience as temperatures peak; and a “long-term resilience” phase of net-negative emissions through carbon dioxide removal (CDR) and lasting adaptation as temperatures eventually decline.
Richard Betts, who leads climate impact research at the UK Met Office, said CDR is not a “get-out-of-jail-free card” and should only be additional to emission reductions that need to be achieved with “even more urgency than before”.
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Critics of CDR have long pointed to the technology’s record of overpromising and underdelivering, and warn it has been exploited by the fossil fuel industry and some oil-producing states to try to delay the clean energy transition.
Not everyone was fully convinced by the UNEP overshoot report. Veteran climate scientist Bill Hare from Climate Analytics said it “does a good job of describing the hole we’ve dug ourselves into” but “a poor job of showing us that there is a way out”. He argued that its thin treatment of the need for a fossil fuel phase-out and ambitious mitigation pathways to cut emissions risk “turning it into a call to apathy rather than a call to arms”.
“Host of challenges” with CDR
Debra Roberts, honorary professor at the University of KwaZulu-Natal in South Africa, told journalists that limiting global warming to around 1.8C is needed to give the world “a realistic and fighting chance” of returning to the 1.5C limit because of the “questionable” feasibility of interventions above that threshold.
CDR comes with “a whole host of challenges”, she added, including the impacts on food and water security of rolling out large-scale programmes and the unanswered questions of whether newer technologies will work at scale and who will foot the bill.
“It’s going to happen in a very, very complex decision-making space where the risks and impacts are dramatically becoming more complex and interrelated,” she said. “That’s why the pressure there is keep those emissions as low as possible because they give us the greatest fighting chance of the return to 1.5C in a more equitable and just way.”
The post UN sets out narrow path back to 1.5C warming after inevitable overshoot appeared first on Climate Home News.
UN sets out narrow path back to 1.5C warming after inevitable overshoot
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From Belém to Antalya – gains, gaps and challenges for a new Just Transition Mechanism
‘Bloody dangerous territory’: UN report an indictment of govt climate inaction
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Climate Change1 year ago
Guest post: Why China is still building new coal – and when it might stop
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Greenhouse Gases2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
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Greenhouse Gases1 year ago
Guest post: Why China is still building new coal – and when it might stop
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Climate Change2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
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Climate Change2 years ago
Bill Discounting Climate Change in Florida’s Energy Policy Awaits DeSantis’ Approval
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Renewable Energy10 months agoSending Progressive Philanthropist George Soros to Prison?
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Greenhouse Gases1 year ago
嘉宾来稿：探究火山喷发如何影响气候预测
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Carbon Footprint2 years agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits