[astrange]

The world is nowhere near overpopulated, most countries are going to see population crashes if anything.

“Overpopulation” is a meme from the 60s coming from a book (Population Bomb) that was disproved the instant it was published. It is, however, a big reason for single family zoning in California - they literally thought it would encourage people to stop moving there and having kids.

[fractallyte]

Overpopulation - a number - is the wrong metric. Instead, we should be looking at the mix of factors (which include overpopulation) that cause the destruction of ecosystems, all the way up to climate change. So that would include: mono-agriculture ('monoculture'), technology powered by fossil fuels (such as logging machines, strip mining machines, etc.), and global transport networks (which hugely enable demand to outstrip supply).

More complicated, but more accurate - and humanity is way past that threshold, even with population crashes.