Imagine a world where everything between the Tropic of Cancer and the Tropic of Capricorn is essentially uninhabitable due to consistently high Wet Bulb Temperatures. Right now, we have over 3 Billion people living in that band (40% of humanity), and about 30% of all commercial agriculture is done here. Bye-bye to both.
Imagine a world where everything between the tropic of that hemisphere and the Arctic/Antarctic circle of that hemisphere has massively chaotic weather, such that commercial agriculture at any significant/effective scale is either impossible or produces utterly unreliable crops from one year to the next. This is where the other 5 Billion (60%) live, and where the other 70% of commercial agriculture is done. Humans could probably live here (although Wet Bulb temps would also make large chunks uninhabitable for parts of the year), but where will the consistent and reliable supply of food come from? Not this part of the world, that’s for sure.
This leaves only the Arctic and Antarctic, which will be quite warm at this point, but has almost no topsoil (or even arable soil in the first place) worth mentioning, and could produce enough crops for only about 2-3% of current human populations.
Now imagine the other 97% of humanity fighting tooth and nail for the right to subsist off of the consistent and reliable food supply from this agriculture-poor part of the planet. Most people who are starving and desperate will gladly shred and decimate infrastructure if it means that they can live another day. And this is the infrastructure that permits efficient, large-scale agriculture and distribution systems that can feed civilizational populations above the single-digit millions level.
Sure, humanity will likely linger on for another century or two. But not as any sort of a serious technological society, nor in any significant numbers beyond the low millions.
Imagine a world where everything between the Tropic of Cancer and the Tropic of Capricorn is essentially uninhabitable due to consistently high Wet Bulb Temperatures. Right now, we have over 3 Billion people living in that band (40% of humanity), and about 30% of all commercial agriculture is done here. Bye-bye to both.
Imagine a world where everything between the tropic of that hemisphere and the Arctic/Antarctic circle of that hemisphere has massively chaotic weather, such that commercial agriculture at any significant/effective scale is either impossible or produces utterly unreliable crops from one year to the next. This is where the other 5 Billion (60%) live, and where the other 70% of commercial agriculture is done. Humans could probably live here (although Wet Bulb temps would also make large chunks uninhabitable for parts of the year), but where will the consistent and reliable supply of food come from? Not this part of the world, that’s for sure.
This leaves only the Arctic and Antarctic, which will be quite warm at this point, but has almost no topsoil (or even arable soil in the first place) worth mentioning, and could produce enough crops for only about 2-3% of current human populations.
Now imagine the other 97% of humanity fighting tooth and nail for the right to subsist off of the consistent and reliable food supply from this agriculture-poor part of the planet. Most people who are starving and desperate will gladly shred and decimate infrastructure if it means that they can live another day. And this is the infrastructure that permits efficient, large-scale agriculture and distribution systems that can feed civilizational populations above the single-digit millions level.
Sure, humanity will likely linger on for another century or two. But not as any sort of a serious technological society, nor in any significant numbers beyond the low millions.