I really think that we can feed way more than our current population using more advanced farming IF WE FIND A WAY TO PRODUCE CHEAP RENEWABLE ENERGY.

The solution would be hydroponic vertical farms. If energy is cheap enough lots of new possibilities emerge.

You could create a 100 floor high skyscraper next to the coast.

-freshwater would be made out of saltwater by evaporation

-artificial lights would simulate sunlight on each floor

-minerals would be extracted from seawater or from the earth's crust

-everything is operated by robots in the farm

-electricity is provided by a solar farm or a fusion reactor

Suddenly arable land and water are not an issue anymore. You have 100x more farmable land. With this technology, feeding 10x the current earth's population seems doable.

**Would this work on a larger scale to feed 100 billion humans?**