evidence: The relationship between climate, diseases of domestic animals and human-carnivore conflicts [...] Human-carnivore conflicts over livestock predation threaten biodiversity conservation and rural development, but the impact of climate and its change on such conflicts is insufficiently studied. The effect of climatic factors on diseases of predation-prone domestic animals and then on conflicts is unstudied, but potentially significant. This empirical case study addressed the conflict between people and leopards (Panthera pardus) in the Hyrcanian humid temperate forest (Iran). We analyzed our questionnaire and other data from all 34 villages around Golestan National Park in terms of probabilities of human-leopard conflicts over livestock predation, diseases of domestic animals and WorldClim bioclimatic variables. Using multiple predictive modeling approaches (generalized linear modeling GLM, Multivariate Adaptive Regression Splines MARS, Bayesian Belief Network BBN, BIOCLIM and DOMAIN), we show that climate continentality and precipitation patterns affect diseases, and more diseases lead to more conflicts. The Community Climate System Model (CCSM4) scenarios forecast aridization of the study area in 2041–2080 and a resultant decline of disease and conflict probabilities by 18.4–21.4% and 10.4–11.9%, respectively. We conclude that diseases can drive human-carnivore conflicts which may become less intense with projected aridization of the studied humid environment.