Climate change impacts on the security environment are real and have the potential to create unprecedented levels of risk through activating dormant conflicts or even triggering a new one over transboundary issues in the southeastern European region. Undeniably, the long-term environmental changes and weather extremes, occurring not only on the territory of southeastern Europe, but also in its neighboring regions, will have a great effect over all of the domains of the socio-economic system and will generate certain risk to the security environment in Bulgaria. Given the fact that the southeastern European region borders some of the areas most vulnerable to climate change, political turmoil, environmental degradation, resources scarcity, and population growth, there is no doubt that projected migratory pressure, economic challenges, and transboundary issues in the region together with political instability will make the Bulgarian security system more susceptible and vulnerable than ever before. Although, direct armed conflict between Bulgaria and its neighbors, based on climate change impacts, is unlikely to occur, climate change impacts might increase the rivalry between the neighbors in southeastern European region over human migration flows, transboundary diseases, and shared resources. Furthermore, the internal security impacts posed by the climate variability over the territory of Bulgaria have the potential to greatly affect the food and water security, public health, and disaster response.