It is believed that the number of people at previous times was also limited by the energy available. See how the population graph looks like -- the real exponen

It is believed that the number of people at previous times was also limited by the energy available. See how the population graph looks like -- the real exponential growth starts at earliest around 300 years ago: https://en.wikipedia.org/wiki/File:Population_curve.svg https://en.wikipedia.org/wiki/File:Population_curve.svg