This section builds on cross-chapter work led by Chapter 16 aimed at identifying and assessing KRs across sectors and regions . KRs are the risks of most pressing concern that are caused or exacerbated by climate change in a given region. A KR is defined as a 'potentially' severe risk, which can either be already severe or projected to become severe in the future, as a result of  changes in associated climate-related hazards and/or the exposure and/or vulnerability of natural and human systems to these hazards, and/or of  the adverse consequences of adaptation or mitigation responses to the risk. In line with the guidelines used in the WGII AR6, the identification of KRs in small islands is based on the chapter authors' expert judgement, using scientific literature and five types of criteria:  importance of the affected system or dimension of the system, which is a value judgement left to readers to make;  magnitude of adverse consequences, based on their pervasiveness, degree and irreversibility, and on the potential for impact thresholds and cascading effects across the system;  likelihood of adverse consequences, although this probability is rarely quantifiable for small islands due to limited downscaled data at a small island level;  temporal characteristics of the risk, including its period of emergence, persistence over time and trend; and  ability to respond to the risk, with the severity of the risk being inversely proportional to this ability.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report