The transnational character of climate-related security risks often goes beyond the capacity of national governments to respond adequately. As such, it both creates challenges for and increases the relevance of intergovernmental organizations (IGOs). It is, therefore, not only important to understand the climate-related security risks that regions are experiencing but also to analyse how regional IGOs are developing their capacities to deal with these risks. This SIPRI Insights presents the findings of an analysis of four regional IGOs: two in Asia, the Association of Southeast Asian Nations (ASEAN) and the South Asian Association for Regional Cooperation (SAARC); and two in Africa, the Economic Community of West African States (ECOWAS) and the Intergovernmental Authority on Development (IGAD). These IGOs were selected because of their significance as regional institutional actors in some of the world’s most fragile and climate-vulnerable areas.