[bandana]

What would those regions be ? The Sahara isn't overpopulated if you look at the density of population, but it can't really sustain anybody. I'm sure there are some rain forests left to cut so we can grow more food for 1 or 2 billions extra people, but what's the end goal ? The world is overpopulated.

[ClumsyPilot]

What are you measuring to determine over or underpopulation? Food production? We grow more food that is required to feed current population, much of world's farming is not efficient, done without modern equipment, etx., and then there is the subject of meat - if we stopped growing feed for animals, and instead seitch to vegetarian diet, we could feed a lot more people.

Then there is the argument that glasshouses are 10x as productive as open fields, so if we were to use them predominantly, we could return land to forests.

[e3bc54b2]

The modern agriculture just means automating depleting natural aquifers and using up topsoil and abusing chemicals at massive scale. Its the agricultural equivalent of optimizing for next quarter, but losing out on next decade.

[ClumsyPilot]

Ancient equivalent is slash-and-burn agriculture, and famines from crop diseases and droughts. I dont think modern vs oldschool juxtaposition is helpfull

[e3bc54b2]

Agreed, but the scale makes all the difference. What few million farmers were doing manually is now being done by same number of of people (approximating, but could be wrong) using massive industrial scale machinery.

Quick google-fu is failing me with actual numbers, but I would not be surprised if we are using 3/4/5 orders of magnitude of water every year compared to 3000 years ago.

[eru]

How would greenhouses use up top-soil?

[JPLeRouzic]

Some places when seen from planes looks literally as vitrified, for example in Netherlands.

[em500]

One of the largest current national problems in the Netherlands is the overproduction of nitrogen compounds, mostly caused by intensive farming. There's more to sustainability than CO2 and topsoil depletion.

[sangnoir]

Those would be the regions that live sustainably - e.g. low insecticide use, but currently have relatively low crop yields that can be improved by adopting some non-harmful modern techniques, like mechanization. You can also compare the average amount of garbage thrown out by a family - developed nations generate a lot of of waste and a lot of greenhouses. If we're capping population growth, the most wasteful regions should be the first.