This second edition of the IEP Ecological Threat Report (ETR) assesses threats relating to food risk, water risk, rapid population growth, temperature anomalies and natural disasters. These assessments are then combined with national measures of socioeconomic resilience to determine which countries have the most severe threats and lowest coping capabilities. These are the countries most likely to suffer from increased levels of ecological-threat related conflict. The main finding from the 2021 ETR is that a cyclic relationship exists between ecological degradation and conflict. It is a vicious cycle whereby degradation of resources leads to conflict, and the ensuing conflict leads to further resource degradation. Breaking the cycle requires improving ecological resource management and socio-economic resilience.