In my first two parts I have covered inequality and its connection to moral and automation. The solution proposed was disconnecting income and value, from work. Improving the safety net, and make food, shelter, healthcare and education accessible to all, so people are free from the fight for survival, and can use their potential to improve mankind.
The next major world problem I want to address, is overpopulation. It's not a new concern and we have at least record of this statement being stated in the first few centuries AD. So, does that mean they where wrong? Not necessary. Civilizations ability to support humans depend on technology. And the worlds capacity to support hunter/gatherers are microscopic compared to agriculture societies. And from the first primitive farmers, trough new technology like irrigation systems, fertilizers, greenhouses and more, we have arrived at a point where the estimated max population is somewhere between 4-16 billion people. We are close, and population growth happens at a speed never seen before. This part I let Hans Rosling explain:
So Hans Rosling take us to 2100 with a population of 11 billion, with roughly the same standard of technology as we have now. What comes next? Here is where the futurism kick in full gear, and we start to speculate about the potential of our civilization and the human race. 4-16 billion people is the limit with today's technology. What is Earths physical limitation? The first limit we reach, and a limit we are dangerously close to, is the accessible area of farmland, and also accessible freshwater. It could well be that we have passed it. So what to do? Several interesting ideas are pursued. First one being hydroponics where plants are grown in a water solution, where all water get recycled and nutritions are added on demand. In combination with vertical farming, where plants grow in several levels, this solution is both space and water saving. It is also easy to keep plants healthy and free from bugs, drought and flood, along with a year long growth season and the possibility to grow food in cities. This is obviously demanding on investment and energy needed, but this is probably the direction future technology will go in all fields.
Another exciting concept I want to name, is "The Sahara Forest Project", where seawater is used to grow food in the desert trough filtration for freshwater, and evaporation for cooling.
www.saharaforestproject.com
That is some near future solutions to the population problem, but where does it end? Here I start to rely heavy on the videos of YouTube content producer Isaac Arthur. He have detailed videos on all kind of futurism content, with a good foundation of physics to estimate the potential of futurism ideas:
First thing space: If we use the hole surface of the world for humans, and assume 10000 ft² for each human, including space for growing food, housing, storage and more, there is room for 546 billion people. This isn't a limit, since you can make a number of levels, until you got room for i tens and hundreds of trillion people. But before you arrive there, other factors will come in an limit.
Next is heat, the true limit: Every human produces heat, and production of food, tools and travel, for each individual add to this number. If we assume every person need 10000 Watts a day for all need, we will hit a highest population of 10 trillion, before total heat production will exceed the cooling capacity of Earth. This is equal to the energy received from the sun, and the percentage of sun energy we are able to utilize, will also be the percentage of 10 trillion we are capable of holding. But without a method getting rid of excess heat, 10 trillion will be the limit, even with new energy sources like fusion.
