[Born to Conserve]

There are dozens of bits of technology that contribute the the high carrying capacity of the world, and there are a few natural bits as well.

Corn yields have gone from 20 bu/ac to 140 bu/ac in the last 80 years.

Soybean 13 to 40
Wheat 15 to 40

If there is an event that disrupts the supply of hybrid seed grain, the yields will drop right back down to the levels of the 1930s, and so will the population.

A bad summer — volcanic ash clouds or a meteorite, or just a plain old bad summer.

A blight.

Social disorder (”Mexican” uprising in the USA)

Trade war.

Plague.

And so on. . . .

[tubaplayer]

What happens when you have to remove the technology?

E.g. no more oil based pesticides, plastics, fertilizers, etc??