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10/16/2025 12:45

Democratizing global climate modeling

Ansa Heyl Presse- und Öffentlichkeitsarbeit
International Institute for Applied Systems Analysis (IIASA)

A new international study co-led by IIASA researchers and Japanese partners aims to democratize the way global climate scenarios are developed. The authors propose a transparent, inclusive research platform that invites participation from scientists worldwide – especially from emerging and developing regions – to ensure that the foundations of climate policy analysis are globally representative and equitable.

As the world strives to keep the ambition of the Paris Agreement alive, a new international initiative aims to transform the way climate change research is conducted. The study, just published in Nature Climate Change, responds to growing concerns that the scientific foundations of climate action, such as the scenarios assessed by the Intergovernmental Panel on Climate Change (IPCC), are largely produced by a limited number of institutions in Europe and North America. This imbalance risks overlooking the perspectives and priorities of developing and emerging countries.

To address this, the authors propose an open and transparent international research platform that democratizes the process of generating and comparing Integrated Assessment Model (IAM) scenarios – the simulations that explore possible pathways to a low-carbon future.

“Climate change is a global challenge, but the science behind climate scenarios has not always reflected a truly global diversity of views,” explains lead author Shinichiro Fujimori, Guest Senior Research Scholar in the IIASA Energy, Climate, and Environment Program and professor at Kyoto University, Japan. “Our proposal aims to open up this process so that researchers everywhere can participate, contribute their expertise, and shape the future of climate policy together.”

Under the new system, every stage of model comparison research, from topic selection to data publication, would follow a clearly defined and open process:

• Proposal and approval of model comparison research content: Researchers will submit ideas for model comparison studies covering topics like climate impacts, renewable energy, or land use to a central body. Proposals will be reviewed and approved based on their scientific merit and global relevance.
• Protocol publication: A detailed experimental protocol will be published outlining the study’s design, methods, required data, and analysis procedures. This will also include the requirements for the model and a list of variables that should be submitted as data. This protocol will be widely shared as an international research project, opening the door to participation for researchers around the world.
• Participation and data submission: Approved projects will be open to all, including smaller institutions and researchers from developing countries. Participants will run simulations according to shared rules and upload their results to a common, standardized database. Data will be subject to quality checks to ensure consistency and reliability.
• Review and publication: After verification and corrections, results will be published in academic journals and also made freely accessible to the public. The open data can then be used by policymakers, businesses, educators, and citizens to support climate action and decision-making.

This approach would allow research teams from across the world, including smaller institutions and early-career scientists, to join major integrated assessment modeling efforts. It also emphasizes reproducibility, data transparency, and broad access to model results.

“Opening up the model intercomparison process is about changing the way science itself is done,” notes coauthor Volker Krey, who leads the Integrated Assessment and Climate Change Research Group at IIASA. “By connecting researchers globally and pooling diverse knowledge, we can make our projections more inclusive, more credible, and more useful for real-world climate decisions.”

The paper highlights the importance of building capacity in developing regions, providing technical infrastructure for data sharing, and ensuring sustainable, balanced funding to enable global participation. The authors emphasize that this is a transition plan, not an overnight overhaul, designed to evolve gradually as international collaboration strengthens.

“We envision a climate research community where participation is not limited by geography or resources,” adds IIASA Energy, Climate, and Environment Program Director, Keywan Riahi, who was also a study coauthor. “By creating open systems and shared standards, we can deliver more inclusive, actionable science.”

The proposal also complements ongoing efforts by IIASA and partners through the Scenario Compass Initiative, which aims to enhance openness and transparency in climate scenario development and data sharing. The authors hope that this framework will serve as the foundation for a new era of global, more equitable climate change research, informing future IPCC assessments and helping shape the climate policies that determine the planet’s trajectory in the face of climate change.

“As climate change is a global issue, the research that informs the policies to address this should be more inclusive. While this may mean sacrificing efficiency to a certain extent, I sincerely hope that the scientific community will move in this direction. I personally intend to work hard to achieve this,” Fujimori concludes.

About the Study
This research was conducted under the JST ASPIRE project (JPMJAP2331), with support from the Environmental Restoration and Conservation Agency of Japan (JPMEERF20241001), the Sumitomo Electric Group Social Contribution Fund, and the Bezos Earth Fund through the Scenario Compass Initiative (Grant G-2023-201305841).

Reference
Fujimori, S., Krey, V., Riahi, K., Sugiyama, M., Hasegawa, T., Edmonds, J., Guivarch, C., Paltsev, S., et al. (2025). Towards an open model intercomparison platform for Integrated Assessment Models scenarios. Nature Climate Change DOI: 10.1038/s41558-025-02462-3

About IIASA:
The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe. www.iiasa.ac.at

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Contact for scientific information:

Researcher contact
Shinichiro Fujimori
Guest Senior Research Scholar
Integrated Assessment and Climate Change Research Group
Transformative Institutional and Social Solutions Research Group
Sustainable Service Systems Research Group
Energy, Climate, and Environment Program
fujimori@iiasa.ac.at

Volker Krey
Research Group Leader Integrated Assessment and Climate Change Research Group and Principal Research Scholar
Sustainable Service Systems Research Group
Energy, Climate, and Environment Program
krey@iiasa.ac.at

Keywan Riahi
Program Director
Energy, Climate, and Environment Program
riahi@iiasa.ac.at

Press Officer
Ansa Heyl
IIASA Press Office
Tel: +43 2236 807 574
Mob: +43 676 83 807 574
heyl@iiasa.ac.at

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Original publication:

https://www.nature.com/articles/s41558-025-02462-3

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More information:

https://iiasa.ac.at/news/oct-2025/democratizing-global-climate-modeling

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New proposal procedure
Source: Fujimori et al. (2025)
Copyright: Fujimori et al. (2025)

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Criteria of this press release:
Journalists, all interested persons
Environment / ecology, Information technology
transregional, national
Research results
English

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