This reprint contains a collection of articles showing how the environmental processes governing the Earth's system can induce the formation of sudden and severe natural phenomena as their most violent expression. Their impact is unevenly distributed over the Earth's surface because of the presence of complex overlapping global or local endogenous and exogenous factors. Climate change and anthropogenic forcing can directly or indirectly exacerbate most of the occurrences at different spatial and temporal scales in the tropospheric area. When such phenomena interact directly with inhabited areas and society, different risk scenarios can develop even for human life itself. The degree of safety in a community is determined by the differential exposure to these events and the level of preparation based on awareness and perception. The social development and uncontrolled (or poorly regulated) spatial growth of human activities via the consumption of soil and natural resources have further contributed to creating vulnerability, increasing the challenges of conscious societies in coping with severe natural processes and their effects. As a whole, all the papers collected here highlight how the protection of territory, in its social and environmental complexity, is ultimately a key element for the pursuit of sustainable development.