Avoiding impacts and impacts avoided: Impact science to inform adaptation action and policy-relevant assessments

Abstract

The Paris Agreement provides a new context for climate impact science. Going forward, robust assessments of the impacts of inaction and impacts avoided by increasing mitigation ambition in line with the goals of the agreement are required. At the same time, the need for climate adaptation has become clear and most countries around the world are having adaptation strategies and plans in place. Climate impact science needs to serve the needs of both communities. Here, we argue that this might not be done best with a “one size fits all” approach, but that there are discernible differences in the objectives and scope, and therefore the methodological approach to impact science to inform mitigation policy and adaptation action. We contextualize the needs for both applications with the recent political and scientific developments and outline key differences with regard to factors such as timescales, resolution, and integration of the socioeconomic context. We discuss the paramount importance of the representation and assessment of impacts of extreme events in particular for adaptation-relevant approaches. While we find that clarity about the multiobjective nature of impact science going forward is important to best serve both communities and to avoid misunderstandings, we also identify substantial synergies and the need for continuous integration between both domains.