4. Energy

Large-scale access to mechanical energy, which began at the start of the industrial era, has endowed mankind – at least for the wealthiest fraction of humanity – with a new power: that of mastering and shaping the world, by pushing back the limits of its physical constraints. The energy sector makes a strategic contribution to the present and future of humankind: our food, comfort, safety, health and entertainment depend on a variety of energy sources, whether "historic", such as hydrocarbons (which are still, and significantly, the main source of energy, see figure 17 ) and nuclear, or "future", such as wind, solar, ocean currents, geothermal and so on.