A long time ago, Humanity had a close relationship with the underground environment that provided shelter. However, it has since abandoned it and colonized a planet on which it now has a preponderant action: the environmental changes that we impose on our environment have an action on the climate, on biodiversity and in return on ourselves. This is all truer for the underground environment in Europe, where the major cities of the Union stand side by side with the prehistoric caves that were once our homes. After having explored with our students the underground ecosystems and the flow of water, we will study the effects of climate change on this environment and the consequences of these deregulations for human society: drought, floods, health and economic disasters.