Journal article: The objective of this paper, drawn from my Presidential address at the 2016 AFSE conference, is twofold. First, it is to convince the readers that the energy transition, from a present where we massively burn polluting fossil fuels that contribute greatly to global warming, to a future where we would be able to obtain our energy from carbon-free resources, is inevitable, and cannot wait. Second, it is to examine whether it is a good idea – or not – to use shale gas as a bridge fuel allowing the world to escape from coal while buying time to make the technological innovations indispensable for the deployment of clean renewable energies on a large scale.