International Symposium on Climate Overshoot, CDR, and SRM: Impacts, Society, and Governance

  • Date：
    Mon, Mar 16, 2026
  • Time：
    15:00-17:30
  • Location：
    Format: Hybrid (on-site and online)
    On-site venue: Grand Conference Room, Sanjo Conference Hall, Hongo Campus, The University of Tokyo
  • Hosts：

    UTokyo Institute for Future Initiatives(IFI) Technology Governance Research Unit & JMIP Research Unit & Geoengineering Model Intercomparison Project(GeoMIP)

  • Co-Hosts：

    UTokyo Center for Climate Solutions(UTCCS), H-UTokyo Lab. (Hitachi and U-Tokyo Joint Research) SWG3, JSPS KAKENHI Kiban B Project “Capacity for Environmental Innovation Policy: A Case Study of Emerging Climate Change Mitigation Technologies” (JP25K03324)

  • Language：

    English
    No simultaneous interpretation will be provided.
    Zoom’s automated translation feature may be used; however, translation accuracy is not guaranteed.

  • Capacity：

    On-site: 100 / Online: 300 (registration will close when capacity is reached)

  • Registration：
    【On-site】Registration Form
    【Online】Registration Form

    Registration required (free of charge)
    Deadline: Friday, March 13 (noon)

    UTokyo Institute for Future Initiatives(IFI) Technology Governance Research Unit & Geoengineering Model Intercomparison Project(GeoMIP), UTokyo Center for Climate Solutions(UTCCS), and H-UTokyo Lab.(Hitachi and U-Tokyo Joint Research) SWG3 collect personal information to provide details about this event and to share information about future activities. This information will not be disclosed to any third party.

Global temperatures are rising rapidly and are likely to exceed the Paris Agreement temperature goals sooner or later. This “climate overshoot” raises difficult questions: What kinds of physical and societal impacts can we expect? How should we respond? What roles might carbon dioxide removal (CDR) and solar radiation modification (SRM) play in managing overshoot risks?
At the same time, these options raise profound social, ethical, and governance challenges:
How should societies evaluate the risks and benefits?
Who has the right to decide if and how CDR and SRM are used?
What governance frameworks are needed at national and international levels?

This symposium brings together researchers working on climate science, CDR, SRM, and social science to explore these questions and discuss directions for addressing the climate overshoot.

Program (tentative)
  • 15:00–15:05
    Opening Remarks

    Seita Emori (Institute for Future Initiatives, The University of Tokyo)

  • 15:05-15:25
    Climate Overshoot and Response Options

    Masahiro Sugiyama (Institute for Future Initiatives, The University of Tokyo)

  • 15:25-15:45
    Sunlight Reflection Methods and their impacts on the climate system: steps towards a more robust assessment

    Daniele Visioni (Cornell University)

  • 15:45-16:05
    Overshoot Impacts and Earth System Risks

    Kaoru Tachiiri (JAMSTEC)

  • 16:05-16:25
    Emit now mitigate later? Reversibility of the Earth system under CDR and SRM 'peak-shaving' simulations

    Jörg Schwinger (NORCE)

  • 16:25–17:05
    Panel Discussion and Q&A

    Discussant:
    Shinichiro Asayama (NIES),Osamu NISHIURA (NIES)
    Panelists:
    Masahiro Sugiyama (IFI, UTokyo)
    Daniele Visioni (Cornell University)
    Kaoru Tachiiri (JAMSTEC)
    Jörg Schwinger (NORCE)

  • 17:05–17:25
    General Q&A with Audience
  • 17:25–17:30
    Closing Remarks

    Shingo Watanabe (JAMSTEC)

Speaker Bio

– Masahiro (Masa) Sugiyama is a Professor at the Institute for Future Initiatives (IFI), the University of Tokyo. His expertise lies in long-term climate policy, with research focusing on climate and energy scenario analysis and the governance of climate engineering from a public engagement perspective. He is a Coordinating Lead Author for Working Group III of the IPCC Seventh Assessment Report. Prof. Sugiyama has also served on the Harvard SCoPEx Advisory Committee and is a member of GESAMP Working Group 41 on Ocean Interventions for Climate Change Mitigation. He holds a Ph.D. in climate science and a master’s degree in technology and policy from MIT.

– Daniele Visioni is an Assistant Professor of Earth and Atmospheric Sciences at Cornell University. His main area of research is global climate modeling and the behavior and impacts of stratospheric aerosols, related to explosive volcanic eruptions and to proposals to deliberately inject aerosols in the stratosphere to potentially ameliorate the impacts of climate change, about which he has published over 100 peer-reviewed publications. He’s the co-chair of the Geoengineering Model Intercomparison Project (GeoMIP), and the co-chair of the World Climate Research Programme Lighthouse Activity on Climate Intervention Research, through which he collaborates with research groups around the world to improve the assessments of various Climate Interventions. He is a Lead Author for the Seventh Assessment Report of the IPCC, and was a coauthor of the 2022 WMO Scientific Assessment of Ozone Depletion.

– Jörg Schwinger is an expert in Earth system modelling interested in the interactions of biogeochemical cycles with the climate system. His current research focuses on the potential role of carbon dioxide removal (CDR) in climate mitigation scenarios, the interactions of CDR with biogeochemical cycles, and the reversibility of the Earth system under overshoots. He has (co-)authored numerous studies that investigate CDR options using Earth system models. More recently, he also became involved in projects that investigate interactions of CDR and solar radiation management (SRM). He is a member of the CMIP7 CDRMIP steering group, and he has been working with the Integrated Assessment modelling community to improve the IAM-ESM modelling chain for CDR methods. He is generally interested in linking his research with other disciplines to better understand societal consequences and options for mitigation of climate change.

– Shingo Watanabe is the deputy director of the Research Center for Environmental Modeling and Application (CEMA) at the Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), and Professor at the Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University. His research focuses on high-resolution modeling of atmospheric waves and interactions between stratospheric aerosols, ozone, and the Earth’s environmental system. He has contributed to numerous climate research projects as a core developer of the MIROC Earth System Model (MIROC-ESM) series. He is a Steering Committee member of the Geoengineering Model Intercomparison Project (GeoMIP) and of Atmospheric Processes And their Role in Climate (APARC), a core project of the World Climate Research Programme (WCRP).

Inquiry

Secretariat of the International Symposium on Climate Overshoot, CDR, and SRM
Email: geomip-2026-group★g.ecc.u-tokyo.ac.jp (★→@)