Presentation Information
[ACG64-P06]Long-term Earth System Responses, Reversibility, and Tipping Points Beyond 2100: Implications for Climate Policy
*Tokuta Yokohata1, Irina Melnikova1, Michiya Hayashi1, Hideo Shiogama1, Kazuya Nishina1, Shintaro Takao1, Yasuto Watanabe1, Tatsuo Suzuki2, Kazuya Kusahara2, Tomohiro Hajima2, Michio Kawamiya2, Yusuke Satoh2, Masakazu Yoshimori3, Ayako Abe-Ouchi3, Yuta Kuniyoshi3, Youichi Kamae4, Hidetaka Kobayashi5, Akitomo Yamamoto6, Katsumasa Tanaka7, KIYOSHI TAKAHASHI1 (1.National Institute for Environmental Studies, 2.Japan Agency for Marine-Earth Science and Technology, 3.The University of Tokyo, 4.University of Tsukuba, 5.University of Toyama, 6.Chiba University, 7.Institut Pierre-Simon Laplace)
Keywords:
Climate Change,Earth System Model,Tipping Point,Climate Policy
The Earth system responds to greenhouse gas (GHG) emissions over a wide range of time scales, with many tipping elements exhibiting characteristic response times of a century or longer. Nevertheless, projections presented in the Intergovernmental Panel on Climate Change (IPCC) assessment reports, as well as in most previous climate studies, have been limited to socio-economic scenarios extending only to the year 2100. As a result, the dynamics of climate change beyond 2100 remain insufficiently explored. To address this gap, we aim to provide a clear, long-term perspective on climate change in the post-2100 period—an underexamined domain—to highlight the urgency of strong mitigation efforts.
In this study, we use the Earth system model MIROC-ES2L to conduct long-term climate projections under scenarios in which the Shared Socioeconomic Pathways (SSPs) are extended to the year 2500. In addition to these extended SSP scenarios, we design numerical experiments in which the global mean temperature is returned toward pre-stabilization levels following a period of stabilization, allowing us to investigate the reversibility of climate-induced changes.
Analysis of simulated atmospheric, oceanic, and terrestrial variables enables us to examine interactions among multiple Earth system components, including key tipping elements. Particular emphasis is placed on assessing whether large-scale transitions triggered by strong climatic perturbations are reversible or irreversible. Scenario-based comparisons further allow us to explore the long-term trajectory of unmitigated climate change and evaluate its consequences for human societies and ecosystems.
In this presentation, we also introduce a new tipping-point research initiative currently being planned in Japan. This project aims to develop future socio-economic scenarios that explicitly account for pathways toward climate stabilization, including overshoot scenarios and pathways in which mitigation measures are delayed or insufficient. Using Earth system models, we will conduct numerical experiments based on these scenarios to elucidate the mechanisms underlying Earth system responses such as tipping behavior. Finally, by synthesizing the latest scientific findings, we aim to provide an integrated understanding of long-term climate risks and to formulate actionable policy recommendations.
In this study, we use the Earth system model MIROC-ES2L to conduct long-term climate projections under scenarios in which the Shared Socioeconomic Pathways (SSPs) are extended to the year 2500. In addition to these extended SSP scenarios, we design numerical experiments in which the global mean temperature is returned toward pre-stabilization levels following a period of stabilization, allowing us to investigate the reversibility of climate-induced changes.
Analysis of simulated atmospheric, oceanic, and terrestrial variables enables us to examine interactions among multiple Earth system components, including key tipping elements. Particular emphasis is placed on assessing whether large-scale transitions triggered by strong climatic perturbations are reversible or irreversible. Scenario-based comparisons further allow us to explore the long-term trajectory of unmitigated climate change and evaluate its consequences for human societies and ecosystems.
In this presentation, we also introduce a new tipping-point research initiative currently being planned in Japan. This project aims to develop future socio-economic scenarios that explicitly account for pathways toward climate stabilization, including overshoot scenarios and pathways in which mitigation measures are delayed or insufficient. Using Earth system models, we will conduct numerical experiments based on these scenarios to elucidate the mechanisms underlying Earth system responses such as tipping behavior. Finally, by synthesizing the latest scientific findings, we aim to provide an integrated understanding of long-term climate risks and to formulate actionable policy recommendations.