A climate impact taxonomy operationalizing IPCC physical driver and risk concepts

The Intergovernmental Panel on Climate Change (IPCC) provides comprehensive information on the physical science of climate change in Working Group I (WGI), as well as on climate impacts, adaptation, and vulnerability in Working Group II (WGII). The breadth of information in the latest IPCC assessment report (AR6) can be difficult to navigate, in particular for end users looking for tailored outputs directly linking physical climate changes to the resulting risks for natural and human systems. While efforts have been made to facilitate the assessment of climate impacts and risks, prominent and systematically applied cross-Working Group products are still missing.

To address this gap, we have developed a climate impact taxonomy that pairs the 35 Climatic Impact-Drivers (CIDs) assessed in AR6 WGI with the eight Representative Key Risks (RKRs) identified in AR6 WGII. CIDs represent physical climate conditions that directly affect societal and ecological systems, while RKRs are clusters of key climate-related risks projected to become severe in a warming climate. Each RKR–CID combination is enriched with structured metadata describing spatial scale, type of change, temporal character, and the IPCC assessment of relevant subsystems. Additionally, the metadata include examples of identified research needs, adaptation linkages outlining illustrative responses by risk component and associated relevant targets aligned with the United Nations Framework Convention on Climate Change (UNFCCC) Global Goal on Adaptation, mitigation linkages, and critical global warming levels. References to relevant WGI and WGII chapters of IPCC AR6 and approved chapters for AR7 guide users toward the appropriate sources for further information.

By translating abstract physical climate indicators into actionable information, the climate impact taxonomy prototype—implemented as a machine-readable lookup table—supports end users, such as adaptation planners and policymakers, with more holistic impact and risk assessments.