Consistent with AR5 findings, there continues to be little observed evidence that climatic variability or change cause violent inter-state conflict. In intra-state settings, climate change has been associated with the onset of conflict, civil unrest or riots in urban settings  , and changes in the duration and severity of existing violent conflicts . Climate change is conceptualised as one of many factors that interact to raise tensions  through diverse causal mechanisms  and as part of the peace-vulnerability- development nexus . New areas of the literature assessed in this report include the security implications of responses to climate change, the gendered dynamics of conflict and exposure to violence under climate change and civil unrest in urban settings. The impact of violent conflict on vulnerability is not addressed in this chapter but does arise in other chapters . Other chapters address non-violent conflict over changing availability and distribution of resources, for example, competing land uses and fish stocks migrating to different territories . A commonly used definition of armed conflict is conflicts involving greater than 25 battle-related deaths in a year; this number represents the Uppsala Conflict Data Program threshold for inclusion in their database, a core resource in this field.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report