Anthropogenic climate change is commonly characterized as a threat to human security. However, the extent to which and under what conditions climate impacts and responses may produce severe risks to peace have seen less systematically assessment to date. This essay provides a conceptual discussion of what risks to peace entail and how such risks might be considered severe, acknowledging that perceptions, values, and social scale must be grappled with in the identification of severity. Informed by available empirical research, the essay then explores the conditions under which climate-related risks could become severe during this century. Three illustrative scenarios based on different assumptions about climate-driven risks and risks related to social responses to climate change serve to illustrate how alternative warming and adaptation trajectories will have distinct implications for the prospect of future peace. The essay ends by reflecting on some implications for future research needs.