What forms of energy will humanity use to ensure, in a few decades, the needs of 9 billions of people? To all, answer the experts today. Renewables as well as classic ones. "Faced with the problem of energy and climate, time is not the exclusion of one energy system over another. Everything is good to take. Without prejudice or angelism ", insists Philippe Pradel, director of nuclear energy at the Atomic Energy Commission (CEA), who recalls that" by 2050, the global energy consumption should double "to reach 20 Gtep (billion tons oil equivalent).