There is a LOT of debate in this area as it introduces many difficult and potentially dangerous topics.
The simplest way though is to take the square miles of livable land (about 25M sqm) and determine how much is needed on average for sustainable food and industrial production per person. The second part is tricky because many people want to figure out the maximum population instead of the ideal one, and there are many variables, such as climate change, which may drastically reduce the number of livable square miles in the years to come.
After spending a generous amount of time researching this topic though, I can say that well-founded high end estimates for sustainable populations for humans is 2B. Still 6B away from current levels and 8-9 billion away for current estimates of year 2100 population estimates.
If you want to find the human population that is sustainable for all species though, that is closer to the 50M-100M that I quoted before. That is to say, the population of humans that would no longer cause lasting damage to other species on the planet. Not surprisingly, this requires an order of magnitude less than even that which I describe above. It’s about 0.25-0.5 sq. miles of livable land per human.
#grownostr
#thinkdangerously