Hundreds of scientists in dozens of institutions are embarking on the next phase of the world’s largest coordinated climate-modelling effort.
Climate-modelling groups use supercomputers to run climate models that simulate the physics, chemistry and biology of the Earth’s atmosphere, land and oceans.
These models play a crucial role in helping scientists understand how the climate is responding as greenhouse gases build up in the atmosphere.
For four decades, the Coupled Model Intercomparison Project (CMIP) has guided the work of the climate-modelling community by providing a framework that allows for millions of results to be collected together and compared.
The resulting projections are used extensively in climate science and policy and underpin the landmark reports of the Intergovernmental Panel on Climate Change (IPCC).
Now, the seventh phase of CMIP – CMIP7 – is underway, with more than 30 climate-modelling centres expected to contribute more than five million gigabytes of data – so much that downloading it using a fast internet connection would take two and a half years.
Here, we look at what is new for CMIP7, including its model experiments, updated emissions scenarios and “assessment fast track” process.
What is CMIP?
Around the world, climate models are developed by different institutions and groups, known as modelling centres.
Each model is built differently and, therefore, produces slightly different results.
To better understand these differences, CMIP coordinates a common set of climate-model experiments.
These are simulations that use the same inputs and conditions, allowing scientists to compare the results and see where models agree or differ.
The figure below shows the countries that have either produced or published CMIP simulations.
During this time, scientists use new and improved models to run experiments from previous CMIP phases for consistency, as well as new experiments to investigate fresh scientific questions.
These simulations produce a trove of data, in the form of variables – such as temperature, rainfall, winds, sea ice extent and ocean currents. This information helps scientists study past, present and future climate change.
As scientific understanding and technical capabilities improve, models are refined. As a result, each CMIP phase incorporates higher spatial resolutions, larger ensembles, improved representations of key processes and more efficient model designs.
CMIP7 objectives
Each CMIP phase has an “experimental design” that outlines which climate-model experiments should be run and their technical specifications, including the time period the models should simulate.
The CMIP7 experimental design has several components.
As in CMIP6, for a modelling centre to contribute, they are asked to produce a suite of experiments that maintain continuity across past and future CMIP phases.
This suite of experiments is known as the “diagnostic, evaluation and characterisation of klima” (DECK) and is used to understand how their model “behaves” under simple, standard conditions. These experiments are designed and requested directly by CMIP’s scientific governing panel.
Alongside the DECK, CMIP also incorporates experiments developed by model intercomparison projects (MIPs) run by different research communities. For example, experiments exploring what the climate could look like under different levels of emissions or those that explore how sea ice might have changed between the last two ice-ages.
Currently, CMIP is working with 40 MIPs. These groups investigate specific scientific questions at their own pace, rather than on timelines prescribed by CMIP.
Running a large number of simulations can take modelling centres a long time. To speed up the process, CMIP7 has launched the “assessment fast track”.
This is a small subset of CMIP7 experiments, drawn from past and present community MIPs, identified through community consultation as being critical for scientific and policy assessments.
Data from the assessment fast track will be used in the reports that will together form the seventh assessment (AR7) of the IPCC.
It will also be used as an input by other groups that create climate information, including organisations involved in regional downscaling and modelling climate impacts and ice-sheet changes.
The figure below shows the different components of CMIP7. It shows how a subset of CMIP7 experiments will be delivered on an accelerated timeline, while the majority of experiments will be led by MIPs.
CMIP7 experiments
There are three categories of experiments set to take place in CMIP7:
- Historical experiments, which are designed to improve scientific understanding of past climates. Model runs exploring the recent historical period also allow scientists to evaluate the performance of models by checking how well they replicate real-world observations.
- Prediction and projection experiments, which allow scientists to analyse what different climates could look like under varying levels of greenhouse gas emissions, as well as near-term (10-year) prediction experiments.
- Process understanding experiments, which are designed to better understand specific processes and isolate cause-and-effect relationships. For example, a set of experiments might change the emissions of one greenhouse gas at a time to see how much each pollutant contributes to warming or cooling the climate.
Modelling centres typically produce and publish their data for the historical and projection experiments first.
CMIP expects the first datasets to be available by this summer, with broader publication recommended by the end of the year, in time to be assessed by IPCC AR7 authors.
Drafting of the reports of AR7 is currently underway. However, countries are yet to agree on the timeline for when they will be published. This presents a challenge for the climate-modelling community, given the difficulties of working with a moving deadline.
(For more on the ongoing standoff between countries around the timing of publication of the reports, read Carbon Brief’s explainer.)
New emissions scenarios
Scientists use emissions scenarios to simulate the future climate according to how global energy systems and land use might change over the next century.
Crucially, these scenarios – also known as “pathways” – are not forecasts or predictions of the future.
The group tasked with designing the scenarios for CMIP phases, as well as producing the “input files” for climate models, is the “scenario model intercomparison project”, or ScenarioMIP.
In a new paper, the group has set out the new set of scenarios for CMIP7:
- High (H): Emissions grow to as high as deemed plausibly possible, consistent with a rollback of current climate policies. This scenario will result in strong warming.
- High-to-low (HL): Emissions rise as in the high scenario at first, but are cut sharply in the second half of the century to reach net-zero by 2100.
- Medium (M): Emissions consistent with current policies, frozen as of 2025, leading to a moderate level of warming.
- Medium-to-low (ML): Emissions are slowly reduced, eventually reaching net-zero emissions by the end of the century.
- Low (L): Emissions consistent with likely keeping warming below 2C and not returning to 1.5C before the end of the century.
- Very low (VL): Emissions are cut to keep temperatures “as low as plausible”, according to the paper. This scenario limits warming to close to 1.5C by the end of the century, with limited overshoot beforehand.
- Low-to-negative (LN): Emissions fall slightly slower than in the VL scenario, with temperatures just rising above 1.5C. Emissions then rapidly drop to negative to bring warming back down.
The figures below show the emissions (left) and the estimated global temperature changes (right) under the seven new scenarios for CMIP7, from the low-to-negative emissions scenario (turquoise) to a high-emissions scenario (brown).
As a set, the ScenarioMIP scenarios “cover plausible outcomes ranging from a high level of climate change (in the case of policy failure) to low levels of climate change resulting from stringent policies”, the paper says.
Compared to the scenarios in CMIP6, the range in future emissions they cover is now narrower, the authors say:
“On the high-end of the range, the CMIP6 high emission levels (quantified by SSP5-8.5) have become implausible, based on trends in the costs of renewables, the emergence of climate policy and recent emission trends…At the low end, many CMIP6 emission trajectories have become inconsistent with observed trends during the 2020-30 period.”
Put simply, progress on climate policies and cheaper renewable technologies means that scenarios of very high emissions have now been ruled out.
However, this progress has not been sufficient to keep society on track for the Paris Agreement’s 1.5C goal. The paper notes that, “at this point of time, some overshoot of the 1.5C seems unavoidable”.
The change to the high end of the scenarios has sparked misleading commentary in the media and on social media – even from US president Donald Trump. A Carbon Brief factcheck unpacks the debate.
Also notable in the new scenarios is the “low-to-negative” pathway, which has the explicit feature of emissions becoming “net-negative”. In other words, through carbon dioxide removal (CDR) techniques, society reaches the point at which more carbon is being taken out of the atmosphere than is being added through greenhouse gas emissions.
Reaching net-negative emissions is fundamental to “overshoot scenarios”, where global warming passes a target and then is brought back down by large-scale CDR.
Overshoot scenarios allow scientists and policymakers to investigate the impacts of a delay to emissions reductions and better understand how the world might respond to passing a warming target. This includes the question of whether some impacts of climate change, such as ice sheet melt, are reversible.
CMIP has encouraged modelling centres to run simulations using the “high” and “very low” scenarios first to ensure downstream users of the data – including groups working on regional climate projections (CORDEX), climate impacts modelling (ISIMIP) and ice-sheet modelling (ISMIP) – have enough time to produce their data for IPCC reports.
These two scenarios were selected as they sit at opposite ends of the spectrum of climate outcomes. The high scenario will demonstrate how models behave under high emissions, while the very low scenario will demonstrate how models behave when emissions are rapidly reduced.
CMIP has recommended that modelling centres then run the “medium” and “high-to-low” scenarios. The remaining scenarios should then follow and no official recommendation has been made yet on their production order.
Other new features
In addition to the assessment fast track and new scenarios, CMIP7 has a number of other new developments.
Updated data for simulations
Climate models use input datasets to define the set of external drivers – or “forcings” – that have caused the global warming observed so far. These drivers include greenhouse gases, changes to incoming solar radiation and volcanic eruptions.
CMIP recommends modelling groups use the same input datasets, as this makes it easier to compare model results.
In CMIP7, the historical forcing datasets available for modelling groups to use have been improved to better represent real-world changes and extended closer to the present day. The historical simulations will be able to simulate the past climate from 1850 through to the end of 2021, whereas CMIP6 only simulated the past climate through to 2014.
CMIP is also planning to extend these historical datasets through to 2025 and maybe further throughout the course of CMIP7.
Emissions-driven simulations
CMIP7 introduces a new focus on CO2 emissions-driven simulations, providing a more realistic representation of how the climate responds to changes in emissions.
In older generations of climate models, atmospheric levels of CO2 and other greenhouse gas concentrations have been needed as an input to the model. These levels would be produced by running scenarios of CO2 emissions through separate carbon cycle models. The resulting climate-model runs were known as “concentration-driven simulations”.
However, many of the latest generation of models are now able to run in “emissions-driven mode”. This means that they receive CO2 emissions as an input and the model itself simulates the carbon cycle and the resulting levels of CO2 in the atmosphere.
This development is important, as climate policies are typically defined in terms of emissions, rather than overall atmospheric concentrations.
This new development in modelling will enable a more realistic representation of the carbon cycle and a better understanding of how it might change under different levels of warming.
Enhanced model documentation and evaluation
All CMIP7 models will be required to supply standardised model documentation that ensures consistency across model descriptions and makes it easier for end users to understand the data.
Additionally, CMIP scientists have developed a new open-access tool that dramatically speeds up the evaluation of climate models.
This “rapid evaluation framework” allows researchers to compare model outputs with real-world observations, providing immediate insight into model performance.
The post Guest post: How CMIP7 will shape the next wave of climate science appeared first on Carbon Brief.
Guest post: How CMIP7 will shape the next wave of climate science
Climate Change
“Next year is too late for regulations”: Beetaloo Energy’s 2GW gas-powered AI data centre a “disaster proposal” destined to cause climate chaos
SYDNEY, Wednesday 22 July 2026 — Beetaloo Energy has secured land from the NT Government for a massive $40 billion “hyperscale” AI data centre near Darwin, which would be powered by 2 gigawatts (GW) of gas power fracked directly from the Beetaloo basin, prompting calls from Greenpeace for urgent federal legislation.
The proposal marks a dangerous escalation in the AI data centre industry’s expansion, which threatens to entrench fossil fuel infrastructure for decades and put immense pressure on the region’s fragile water resources — while continuing to be unregulated.
Joe Rafalowicz, Head of Climate and Energy at Greenpeace Australia Pacific, said: “This disaster proposal for a 2GW gas-powered AI data centre in the NT is a shocking example of the unchecked expansion of hyperscale data centres in Australia. It is also, critically, more evidence for the urgent need for a moratorium on all new data centres until strong, binding regulations are put in place to protect our communities and climate.
“This proposal mirrors the frenzied, unchecked expansion currently wreaking havoc on communities in the US. We are seeing cowboy data centre operators treat Australia like a playground, steam-rolling ahead with projects that would lock down precious water resources and spike emissions, despite the overwhelming community opposition.
“Every day, more councils, communities and environmental groups are joining Greenpeace’s call for a moratorium on data centres, yet as of today there is still no system of safeguards or rules in place to regulate these companies.
“While Beetaloo Energy and the NT Government prepare to bulldoze ahead with this climate and water disaster, the Prime Minister is asleep at the wheel, promising to legislate a vague set of standards next year.
“Next year is too late, and anything less than mandating data centres cover their own energy demand, and then some, with new renewable energy is not enough.”
-ENDS-
Media contact
Lucy Keller on 0491 135 308 or lucy.keller@greenpeace.org
Reports of human rights and environmental abuses linked to Chinese companies’ overseas investments in the mining and refining of minerals needed for the clean energy transition are on the rise, research by a monitoring group has found.
The number of recorded allegations of harm at projects tied to Chinese firms have increased every year since 2021, rising to 148 in 2025, according to the Business and Human Rights Centre (BHRC). On Wednesday it released new data showing that a total of 434 allegations of abuse were made against Chinese-backed projects over the five-year period in projects across the world.
The world’s top cleantech manufacturer, China is also the leading financier of critical minerals projects worldwide. The country has committed more than $120 billion in foreign direct investment into mineral mining and processing since 2023, Australian think-tank Climate Energy Finance recently found.
“China plays a central role in global transition mineral supply chains, and as such has a unique opportunity to raise the bar on human rights and community engagement at every stage of mining,” said Michael Clements, BHRC’s executive director.
“While there have been encouraging developments, from stronger regulations to more company engagement, there remains a gap between human rights commitment and action,” he said.
The report comes as communities affected by Chinese-backed mineral projects have filed the first two cases to a Beijing-based mediation mechanism intended to bring willing Chinese companies to the discussion table with affected communities.
Allegations of harms on the rise
BHRC’s latest analysis – including data for the period 2023-2025 – covered mining, smelting and refining projects for 11 minerals considered key to manufacturing clean energy technologies such as batteries, EVs and solar panels needed to move away from climate-heating fossil fuels.
The highest number of abuses was recorded in Indonesia, the world’s largest producer of nickel, which is used to make EV batteries. After the Indonesian government banned exports of raw nickel, Chinese firms invested billions of dollars to develop a large-scale nickel smelting and processing industry in the Southeast Asian country, largely powered by coal.
Other countries with a high number of recorded harms include the Democratic Republic of Congo, where Chinese firms dominate cobalt and copper production; Myanmar, where unregulated rare earths mining has caused widespread environmental destruction; Serbia, where Chinese-backed mining of some of Europe’s most significant copper and gold deposits is swallowing land and homes, and Zimbabwe, where Chinese investments have turned the nation into Africa’s top lithium producer.
Growing risks for people and nature
Allegations tracked by BHRC included negative impacts on local livelihoods, health and land rights, workers’ health and safety and work-related deaths, as well as water pollution and environmental contamination. In addition, 18 people were attacked for raising concerns about Chinese transition mineral projects between 2023 and 2025.
The report shows that 10 Chinese companies, including Zijin Mining, Tsingshan Group and Zhejiang Huayou Cobalt, accounted for nearly two-thirds of all allegations recorded in the last five years. It found that some Chinese companies “still appear to turn a blind eye to these issues” but noted that several others have been more responsive to allegations of abuse. However, even among companies with human rights policies, implementation remains a challenge, BHRC warned.
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Zijin Mining and Zhejiang Huayou Cobalt repeatedly responded to the allegations of harm by saying they take environmental and social risks seriously and adhere to international standards. Tsingshan Group never responded to BHRC’s requests for comment.
Platform for dialogue between communities and Chinese firms
At the same time, Chinese authorities have made “significant progress” on introducing a more specific framework for managing environmental and social risks in overseas investment, BHRC said.
This includes global consultation on a draft Sustainable Mining Code, adherence to UN guiding principles on business and human rights, and greater emphasis on oversight of companies operating overseas.
The China Chamber of Commerce of Metals, Minerals & Chemicals Importers & Exporters (CCCMC) set up a mediation and consultation mechanism intended to provide a platform for dialogue between affected communities or civil society groups that have raised concerns and Chinese companies.
More than three years since its launch, the mechanism has now received its first two complaints from local communities and many more are considering filing a case, Margaux Day, executive director at the nonprofit Accountability Counsel, told an event hosted by Climate Home News last month.
“This is incredibly exciting in that it fills a governance and accountability gap where often communities who are seeking to protect their rights and the environment can’t reach someone who will respond to them,” she told the panel discussion at London Climate Action Week.
Climate Home News understands that the complaints were filed by communities in Latin America and Southeast Asia over labour rights and resettlement issues. No information about the cases has yet been made public. The mechanism’s secretariat did not respond to Climate Home News’ questions.
The mechanism was set up after the Chinese regulator for banks and insurers called on investor-level institutions to establish complaints bodies to hear from communities outside of China. But whether the new initiative will prove effective in tackling grievances remains an open question.
“Real potential” for better mining practices
Participation in the mechanism is voluntary for Chinese firms and it doesn’t have a fact-finding function, nor can it impose provisions for compensation or compliance with human rights standards.
But Day told Climate Home News that, if successful, it could bring companies to negotiate an outcome that is better for people and the planet and leads to more sustainable mining practice.
Chen Yu, an independent China advisor for campaign group Global Witness, agreed that the mechanism holds “real potential”.
“There exists nothing else at a similar level to promote dialogue between communities and Chinese mining companies in particular,” she said.
For companies, the mechanism opens “a channel for problem-solving and dialogue with communities”, she added, as “Chinese companies often remain cautious of approaching affected communities directly, afraid of making the problem bigger”.
However, Chen said the mechanism remains at an early stage of development, faces resourcing challenges and is not yet sufficiently understood by communities in mining areas or Chinese firms.
To help it address some of these challenges, the secretariat is currently seeking technical support from a range of organisations, including civil society groups. But, Chen said, “it will take time for the mechanism to show its value”.
The post Allegations of harms at China-backed transition minerals projects rise appeared first on Climate Home News.
Allegations of harms at China-backed transition minerals projects rise
Andreas Sieber is head of political strategy at 350.0g. Cat Abreu is director of the International Climate Politics Hub.
From the US abduction of Venezuela’s president at the start of this year to the Iran war which rumbles on, disruption is the new normal for global geopolitics, more often than not linked to conflict over supplies of oil and gas.
Events so far in 2026 – driven largely by the desire of the Trump administration to grab control of fossil fuels around the world – show that the climate community’s approach to energy diplomacy will have to evolve if we are to operate effectively and push for climate action in such a volatile landscape.
Today’s climate and energy governance must be able to cope with trade wars, genocide, fascism, spiralling inequality and challenges to multilateralism. The increasingly dominant paradigms of economic competitiveness, energy security and green industrialisation can help drive the transition but they also challenge our collective mission to deliver an equitable green shift.
US-China rivalry dominates
Longer-term geopolitical trends that are seeing power move from West to East and North to South have fuelled a US–China “superpower rivalry”, which is pulling the global economy apart and reining in trade.
A key question will be how the fracture “lines” are drawn: by the US and China, or also by other countries or blocs? Many governments will try to remain “in the middle” between the two giants to capture economic gains from both sides. Yet despite the language of “strategic autonomy”, Washington and Beijing may be in a position to force choices via market access, export controls and sanctions.
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At first glance, this may not seem particularly relevant for climate and energy politics. But Huawei’s exclusion from 5G operations across the political West and India following the so-called Clean Network Campaign by the US government serves as a warning of what could happen to climate green tech.
And the recent debate to cut out Chinese inverters from European markets follows the same pattern – US security forces perceive a risk and start encouraging their allies to drop Chinese technology.
The new drivers: competition and security
Despite this fracturing geopolitical and economic context, energy transition is still happening. To ensure it is effective and equitable, we need to understand what is driving it and how to adapt climate politics so that it better responds to these drivers.
Put simply, China is supplying the world with low-cost renewables (roughly 60% of critical wind and 80% of solar components), batteries, EVs and other key elements. Other countries now also want their piece of the green tech pie and are forming industrial policies to get it.
It is this new competitiveness-driven logic that will shape the quest for decarbonisation, which has shifted from cooperating around the cost of tackling climate change to rivalry for the benefits of climate action.
Over 90% of new renewables projects are now cheaper than fossil alternatives. Gas-fired power is 3–4 times more expensive than solar and wind. In 2015, most decarbonisation policies were “traditional” emissions-cutting strategies like carbon pricing or net zero dates, whereas green industrial policies now underpin the majority.
Iran war could boost fossil fuel phase-out push, says Colombian minister
Meanwhile, security has become a central driver of energy politics. We are living through the second major fossil fuel crisis in just four years. Elevated oil and gas prices will impose up to $1 trillion in additional costs on the global economy by the end of the year if disruption continues in the Strait of Hormuz. Fossil fuel supply chains have exposed countries to conflict, coercion and brutal price shocks.
Fossil fuel volatility destabilises whole economies – higher fuel costs drive up food prices, increase political instability, and push millions into poverty and hunger. This incentivises governments to shield themselves from global shocks, especially in countries that are net fossil fuel importers and home to roughly three-quarters of the world’s population.
Yet security fears can cut both ways. The same instability that makes fossil fuel dependence untenable is also sharpening concern over China’s dominance of critical clean technologies and supply chains.
Equity, cooperation and the opportunity for change
Developing countries benefit from the rapid uptake of renewables enabled by low-cost Chinese technologies. But significant fiscal space and public investment is needed for the electricity grids and infrastructure required to fully unleash the energy transition, as well as for green industrialisation to diversify revenue streams.
Despite this, industrial-scale domestic production and ownership often remain out of reach for too many countries that lack the fiscal space to allow green supply chains to flourish and compete with their traditional industrial base. But more just and diversified green tech supply chains could be achieved with concomitant support.
Can giant batteries unlock Africa’s green industrial future?
For the first time in decades, the international order is being substantially reshaped. If within this context, decarbonisation is increasingly driven by green industrial policy, energy security and competitiveness, the climate policy community must better anticipate where these debates are moving. We must speak the same language, and enter the forums where decisions are made, including security, trade and bilateral or trilateral spaces.
We should build on an enlightened self interest recognising that cooperation remains essential and beneficial. This includes using the UN climate process differently: less as an ever-expanding negotiation machine, and more as a space for norm-setting, political alignment and deal-making. In an age of fragmentation, effective cooperation must not only be framed as necessary but thought of as a strategically compelling source of resilience and shared advantage.
The post Energy transition policymaking must evolve to fit an age of rupture appeared first on Climate Home News.
Energy transition policymaking must evolve to fit an age of rupture
“Next year is too late for regulations”: Beetaloo Energy’s 2GW gas-powered AI data centre a “disaster proposal” destined to cause climate chaos
Allegations of harms at China-backed transition minerals projects rise
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