発表論文

Risk implications of long-term global climate goals: overall conclusions of the ICA-RUS project

著者
Emori S., Takahashi K., Yamagata Y., Kanae S., Mori S., Fujigaki Y.
雑誌名
Sustainability Science
DOI
10.1007/s11625-018-0530-0
概要

We have assessed the risks associated with setting 1.5, 2.0, or 2.5 °C temperature goals and ways to manage them in a systematic manner and discussed their implications. The results suggest that, given the uncertainties in climate sensitivity, “net zero emissions of anthropogenic greenhouse gases in the second half of this century” is a more actionable goal for society than the 2 or 1.5 °C temperature goals themselves. If the climate sensitivity is proven to be relatively high and the temperature goals are not met even when the net zero emission goal is achieved, the options left are: (A) accepting/adapting to a warmer world, (B) boosting mitigation, and (C) climate geoengineering, or any combination of these. This decision should be made based on a deeper discussion of risks associated with each option. We also suggest the need to consider a wider range of policies: not only climate policies, but also broader “sustainability policies”, and to envisage more innovative solutions than what integrated assessment models can currently illustrate. Finally, based on a consideration of social aspects of risk decisions, we recommend the establishment of a panel of “intermediate layer” experts, who support decision-making by citizens as well as social and ethical thinking by policy makers.

江守正多「気候変動問題の長期目標をリスクの観点から考える〜『ICA-RUSプロジェクト』の成果のまとめ〜」地球環境研究センターニュース2018年4月号