1. Natural and Anthropogenic Gradients

Any type of phenomena is generated by a gradient. Therefore, also natural and anthropogenic hazards are also controlled by physical or socio-economic gradients. There are three types of hazards affecting the Euro-Mediterranean Region: (1) natural risks such as earthquakes, tsunamis, volcanic eruptions, floodings, landslides, geochemical degassing, etc. generated by physical gradients in the solid Earth and the atmosphere; (2) anthropogenic gradients such as the CO₂ rise determined the ongoing global warming generating higher evaporation of the marine areas, implying stronger and more frequent storms and precipitations inland, as well as the expansion of desertic regions, plus, sea-level rise threatening coastal areas due to ice melting in the polar regions; (3) cultural and socio-economic gradients between the several and variegated populations living all around the Euro-Mediterranean area may be considered as historical richness, but are instead often used as the trigger for international disputes, due to the higher demographic growth, contemporaneous desertification, and lower income per capita in Africa with respect to Europe, determining gradients able to fueling migration of the population from south to north. To be ready to face natural and anthropogenic catastrophic events, we need to increase our knowledge of the Earth's mechanisms concerning what we know at present to forecast their evolution. For example, we should all together work to immediately fight climate change, governing and lowering such influence of human beings on natural equilibria. We must know gradients in order to govern them, if possible.