> I don't think there is a hard limit on number of people. We have around 7 billion people now. At the current growth rate of about 1%/yr the biomass of human

> I don't think there is a hard limit on number of people. We have around 7 billion people now. At the current growth rate of about 1%/yr the biomass of human beings will exceed the current weight of the planet Earth around the year 7200. Not long after that this hypothetical growing humanity would collapse into a black hole under its own weight. It'll already be quite cramped in the year 5400 with 1% growth. We'll have 5 people for every square meter of the surface of Earth (we have 510.1 trillion m^2). That's about the density near the front-row of a standing concert.