What is the ideal population for planet earth?
The present world population is 7.6 billion, with 9 billion predicted by 2050, and 11 billion by 2100. Clearly, this is way too many people. Carbon emissions cannot be sequestered, food production may be able to keep up if we consume wheat, sugar, rice and corn. But, meat and garden vegetables will be available to very few people. Fresh water, and sewage treatment will be issues too.
Reduction of the future population may occur from disease (the red death), nuclear war, famine, etc. Assuming that will happen, what is best size population for a stable and affluent Planet Earth in the future, say in the year 2800?