Probably the founding father of Geology, Sir James Hutton was raised as a doctor but his passions for the nature surrounding his farm led him to rocks, then specimens, then fossils. The result was what we might call a comparative physician – the first paleontologist, in fact. His upbringing in medicine had given him the classical knowledge of his time, from Latin to mathematics, and from biology to drawing. Not only did the lack of a specific scientific discipline bring Sir Hutton to devise a novel field of study of his own – it also molded strands of his formal learning into a synthesis of intellectual tools. These days, hyper specialization has brought upon novel discoveries of paramount importance and marvel, from graphene to vaccines. It also is a means of necessity in applying for academic positions and to publish in ever nascent journals. This architecture, however, reflects a system of parallel disciplinarity, with scientific fields somehow on their own course. On the other hand, complexities at stake require solutions that may well evade any given single field, at times astray from usual avenues. Such approach not only entails multi-disciplinarity (diverse teams – yesterday), but it also requires cross-disciplinarity (across specific disciplines – today) and, especially, trans-disciplinarity (beyond firm disciplines – today and tomorrow). For their very nature, geosciences are bound to glean lessons learned from the past to provide insight into the future. Geoscientists were once thought to study ancient rocks, fiddle with very slow-moving tectonic plates, and bantering about invisible earth’s features, too large, or too deep, or too far away to even imagine for us earthlings. But the geosciences are more than ever side by side with some of the most pressing issues surrounding contemporary societies – after having been at the heart of a couple of global energy revolutions. From a series of examples, this work thus tries to put into perspective: Hazards stemming from multiple, at times unpredictable sources; The precious role of geosciences to decipher them – and to forecast them; The complexity of natural hazards, the (need of) flexibility in human planning; Modern issues challenging societies and economies – today, tomorrow, and thereafter.