Optimum Population Size Revisited.

Abstract

In 2019, average world energy consumption per capita was 22.308 MWh (total energy consumption = 171,240 TWh, for all purposes; global population in 2019 = 7.676 billion), but total non-nuclear and non-CO2-emitting renewable energy sources only contributed ~17,400 TWh, or ~2.267 MWh per capita per annum. This would only be enough to sustain a global population of 779,989,242, approximately that of 1750.