The interesting parts of the Earth system are those that perform work, show dynamics, build and maintain structures, deplete gradients, dissipate and produce entropy – in short, dissipative systems. These dissipative systems operate far from the boring state of thermodynamic equilibrium and show interesting behavior, such as well formed structures and power-law scaling. A good topic for a short intro course, because it is one of the lesser known aspects of Earth systems, and a good occasion to meet and talk about. That‘s what we‘ll do in September at the University of Florence in Italy. And to make the topic not quite about everything on Earth, we will focus on hydrogeosystems.