I remember learning in school that there were 6 billion people in the world. Recently I realised that we are over 8 billion already.
And all of us want to have a good life and those who grew up poor want to consume. 100% understanable.
Tech makes a big difference: If humans didn’t farm our population would be ~100 million; If we tile the world in greenhouses, and if we’re careful with our resources, we could have ~10 trillion.
Where? Physically, where? Compressed into tiny apartments all over the planet, like sardine cans?
I’d only be happy with that population level if we had a lot of Arcology-style mega-buildings to give each of us enough space and parkland, but that’s rather my point: tech enables the otherwise impossible.
63% of protein and 82% of calories come from 23% of agricultural land, which is itself 51% of habitable land, which is itself 71% of land, which is 29% of the surface. That agricultural land mostly isn’t greenhouses, which are far more productive than open ground, but even greenhouses are not the most productive food sources we know how to make.
Even without changing the ratio of farmland where greenhouses or better are used (a cunning trick if you can do it, given you’d need something like a greenhouse or aeroponics to turn uninhabitable land into farm land), that takes us up to 7.7-fold increase in carrying capacity for pure land use and 26.6-fold if you add in potential aquaculture.
Most of us don’t have a reason to care more about efficient use of farmland. Some places do, which is why greenhouses, hydroponics, and aeroponics exist at all, but most of us don’t.
And then, separately from greenhouses (probably before but I don’t know how to account for it), there’s better crop choices, and finally GM crops.
If everyone wants to live and consume like a 21st century American, we need to make sure the world only has around 2 billion people (this is based on a fact I read that we need the resources of 4 Earths to sustain American style consumerism globally).
As our quality of life goes up more, the number of humans Earth can support gets smaller. Depending on the target global average lifestyle, we probably already have too many people by a significant amount.
As I said increasing technology and life comforts genrally reduce population growth, let's hope for other technology miracles as well. This is a reasonable position. I spent the weekend in the Pennsylvania wilderness in an area that in the mid-1800s had been stripped bare by logging and was now a preserved and expansive wilderness. Humanity can and will adapt. Believing so helps me sleep at night.
Yes, its true that if global population was 10 million and all lived in 50-ppl villages you could shit in the streets and still not get the Plague, pollute to your heart's content and still be fine, practice slash-and-burn agriculture and still have forests left. But then you wouldn't have most products of civilisation in the first place.
Once you start getting cities, you cant shit in the street, you need suers and restrictions on pollution
I suspect the main barriers are political. There is a lot of suffering in the world that has little to do with lack of resources, yet persists for political reasons.