Overpopulation


Look at it this way:
Imagine you ignore all the oceans and join all the land mass on earth together. Now you spread out the total population evenly over the landmass. with the current population, your neighbours would be about 98 meters ahead, behind, left and right of you.You have about 10,000 sq m on which to support your life.
Remember, you 10,000 sq m includes farmland, deserts, mountains, jungle, rivers, a good chunk of Antarctic ice fields, tundra, cities etc.
On this area you not only have to feed yourself with crops and livestock (remember, livestock need to eat too!) but you have to mine your minerals for manufacturing and energy, you need a space to live, a space to work, a space to relax, a space for waste products that wont contaminate everything else, you have to concede some of your space for factories, shops, infrastructure etc.
Over the past 20 years (Yes, in our own lifetime!) we crossed a threshold, we are now consuming more than the planet can regenerate. If the population doubles (75 years from now) that 98 meter distance becomes 71 meters, another doubling (150 years) and that distance is less than 50 meters. The arth does have a maximum carrying capacity for humans, and we've reached it.
Future wars and genocides will be about resources (including but not limited to food and water).
Superpowers will find excuses ( threats of terrorism, or whatever) to exterminate less advanced nations to win their space and resources for own use.
Your calculation for living space omits