7. Ever more renewable energies

Along with animals and sometimes slaves, renewable energies have been the longest exploited energy sources by human civilizations. It might be mistaken to think that we use less renewable energy today than our ancestors did. This is not the case. It is estimated that in 1800, humanity, with a population of around 1 billion, consumed around 0.2 Gtoe of primary energy, or perhaps a little more. This was essentially biomass, with wind and water energy being quantitatively marginal. Today, some 3 billion people use biomass as their main source of energy, accounting for just over 1 Gtoe. To this must be added hydropower, which produces almost 17% of the world's electricity, and other renewable energy sources which, although less important, contribute to the global energy balance. Renewable energies have therefore far from disappeared, but they have been supplemented by the massive use of fossil...