[thegrimmest]

> slow creeping existential threat

I struggle to see how even the worst predicted outcomes of climate change are an existential threat to the human species or our civilization. In the worst case a few billion people die or are displaced. Our species will carry on.

[BLKNSLVR]

Losing a few billion people is an existential threat to civilisation.

Civilisation is quite the fragile structure, built slowly and carefully over centuries of large scale cooperation between much of the populated world.

Scarcity of the basest necessities brings uncivilisation.

[thegrimmest]

I don't think so, civilization has progressed basically unidirectionally for all of history. We've never gone "back to the stone age" or regressed in any meaningful capacity, despite catastrophes of various scales.

[BLKNSLVR]

I'm no historian, but:

https://gizmodo.com/10-civilizations-that-disappeared-under-...

[thegrimmest]

Humanity as a whole has never gone back an age. Once we learned to cultivate plants, domesticate animals, smelt iron, we've never unlearned. We'll similarly never unlearn how to build nuclear reactors or microprocessors. I'm happy to entertain such a suggestion, but I don't see a mechanism by which climate change can destroy enough people and infrastructure to create such an effect. Our knowledge is too distributed and resilient.

[BLKNSLVR]

I understand your point, but the scale of the potential effects of climate change combined with all the societal structures in place, and the number of people required to keep that structure "fed", that allow for the knowledge to be passed down makes me feel that even one generation worth of a significantly depleted humanity (something like 10% of current, spread around the world) who are largely occupied with just ensuring enough food and shelter to survive, will see those societal structures need to be rebuilt from scratch.

[M95D]

> We'll similarly never unlearn how to build nuclear reactors or microprocessors.

Who's "we"? I don't know about you, but:

- I did learn a bit of agriculture and I could probably teach that to the future generation.

- I never learned how to build a nuclear reactor or microprocessor. Did you? Could you teach that?

[thegrimmest]

A kid famously built a neutron emitter in his suburban shed in the 90s[1]. His goal was to build a breeder reactor.

I don't personally know how to do these things either. I know how to program computers, and could teach that. My point is that I am a small component of a vast, distributed system of knowledge that is very hard to destroy. It doesn't seem practical to kill every nuclear physicist and destroy every copy of every document that describes nuclear physics. I don't see how climate change could do this.

1. https://en.wikipedia.org/wiki/David_Hahn

[silverquiet]

I have never died and so I don't think ever I will.

[kachapopopow]

Losing the means of food production in the most fertile parts of the world would pretty much wipe out more than "a few billion people". It's likely that we'd lose the means to support even a billion human lives and would have to redirect our efforts into survival rather than progression setting us back hundreds of years.

edit: not to mention everyone going into war with each other for securing the small amount of places that are able to produce food.

[thegrimmest]

New fertile areas will become available, Siberia and northern Canada for instance. Do you have a serious scientific source that projects the loss of agricultural capacity to the degree you're suggesting?

[kachapopopow]

The land itself has to be fertile that's why the moon-belt is called like that and is currently where most of the wheat (in europe at least) is being produced. This process happened over thousands of years and is not easy to 'move' or 'prepare' land like that.

New regions would struggle to cultivate new land without fertilizers and the current fertilizer sector would struggle to operate (current sector is built around the availability of ammonia as far as I'm aware).

Your best bets would yes: Siberia, Canada. But it would take maybe few millennia before that land could be used for agriculture and it would effectively become the new oil of the world sparking a new wave of conflicts as I mentioned before.

Our current food supply could be destroyed in decades not millennia given enough heatwaves and other natural events.