The hazard components of representative key risks The physical climate perspective

• Main Authors: Tebaldi, Claudia, Aðalgeirsdóttir, Guðfinna, Drijfhout, Sybren, Dunne, John, Edwards, Tamsin L., Fischer, Erich, id_orcid:0 000-0003-1931-6737, Fyfe, John C., Jones, Richard G., Kopp, Robert E., Koven, Charles, Krinner, Gerhard, Otto, Friederike, Ruane, Alex C., Seneviratne, Sonia I., id_orcid:0 000-0001-9528-2917, Sillmann, Jana, Szopa, Sophie, Zanis, Prodromos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2023
• Subjects: permafrost
• Online Access: https://hdl.handle.net/20.500.11850/612230; https://doi.org/10.3929/ethz-b-000612230

The framework of Representative Key Risks (RKRs) has been adopted by the Intergovernmental Panel on Climate Change Working Group II (WGII) to categorize, assess and communicate a wide range of regional and sectoral key risks from climate change. These are risks expected to become severe due to the potentially detrimental convergence of changing climate conditions with the exposure and vulnerability of human and natural systems. Other papers in this special issue treat each of eight RKRs holistically by assessing their current status and future evolution as a result of this convergence. However, in these papers, such assessment cannot always be organized according to a systematic gradation of climatic changes. Often the big-picture evolution of risk has to be extrapolated from either qualitative effects of “low”, “medium” and “high” warming, or limited/focused analysis of the consequences of particular mitigation choices (e.g., benefits of limiting warming to 1.5 or 2C), together with consideration of the socio-economic context and possible adaptation choices. In this study we offer a representation – as systematic as possible given current literature and assessments – of the future evolution of the hazard components of RKRs. We identify the relevant hazards for each RKR, based upon the WGII authors’ assessment, and we report on their current state and expected future changes in magnitude, intensity and/or frequency, linking these changes to Global Warming Levels (GWLs) to the extent possible. We draw on the assessment of changes in climatic impact-drivers relevant to RKRs described in the 6th Assessment Report by Working Group I supplemented when needed by more recent literature. For some of these quantities - like regional trends in oceanic and atmospheric temperature and precipitation, some heat and precipitation extremes, permafrost thaw and Northern Hemisphere snow cover - a strong and quantitative relationship with increasing GWLs has been identified. For others - like frequency and intensity of tropical ...