Compound Climate Events and Cascading Impacts in the IPCC AR6 : Analysis of Gaps and Avenues for the AR7

Abstract

Compound weather and climate events and risks (CE) and their cascading impacts (CI) have emerged as new key risks to human societies and ecosystems and have therefore become a major focus of climate research. Here, we review the coverage of CE and CI in the IPCC's Sixth Assessment Working Group I (WGI) and Working Group II (WGII) reports to inform priorities for their treatment in the 7th IPCC cycle. We analyze the use of the terms compound ( ing ) ( N = 422) and cascade ( ing ) ( N = 216), considering five variables: conceptual landscape, CE type, system, geography, and time horizon. The results reveal a strong conceptual and narrative disconnect between the two IPCC reports, with a separate treatment of CE and CI, and a limited bridging of CE and CI with climate change adaptation; six new types of emerging CE; the prevalence of compound flooding, compound droughts, and compound heat/heatwaves/droughts and/or wildfires. The most heavily cited regions are Oceania and Africa for CE and the Arctic for CI, whereas the most cited archetypes are coastal and urban areas. Post‐AR6 literature provides conceptual and methodological frameworks to help overcome the limitations of the AR6's treatment of CE and CI over the 7 th IPCC cycle. These include a conceptual framework, models for cause‐effect‐response process chain analysis across systems, borders and timescales, and grounded storyline and pathway approaches. The outlines of the AR7 offer powerful opportunities to fill the AR6 conceptual, topical, and risk narrative gaps, by identifying CE and CI and their links with adaptation as key cross‐cutting areas. This article is categorized under: Climate, History, Society, Culture > Ideas and Knowledge Integrated Assessment of Climate Change > Integrated Assessment by Expert Panels Trans‐disciplinary Perspectives > Regional Reviews