Well, then you may have a catch-22 where the expense of having your child could cause making the world unlivable for that child thus condemning it or its descendants to non-existence. Thus generalized to the whole population the best action to maintain the ability to have those valued children is to have fewer of them on average. So we're back to the same conclusion.

How do you reconcile the future warfare and famine risk to your N existing children caused by the additional carbon of your hypothetical N+1 vs your utility of having an N+1th child, though? Because that is the actual formulation.

You reconcile it by reading some history books and realizing that life has always been tough and that the future probably won't be any tougher than the past.

Except for the fact we are, in decades, affecting climate in a way that took several millennia previously and we've contaminated the water and air with not only microplastics but all sorts of outright toxic compounds.

Then of course we are making species go extinct 1,000 to 10,000 times the background rate because we are contaminating ecosystems, clear-cutting ecosystems and causing ecosystems to collapse by directly influencing climate making it impossible for parts of those ecosystems to survive.

Life is already orders of magnitude 'tougher than the past'.

I mean, you are absolutely, 100% incorrect. It's textbook fallacy. X is tough, Y was tough, we survived Y, and therefore we can survive X.

The planet has never been through warming as rapid as what we are going through in known geological (not human) history. There was a paper hosted and copublished by NASA to that effect in the last month. It's literally unknown how much life can survive the velocity of the change that is in progress.

What "history books" should I read about climate science, too?

Climate change has caused famine and strife for humans in the past. It's one of the more common reasons for civilizational decline. Sure, this round of climate change is worse. But our ability to fend for ourselves is better.

Again, 100% fallacy. "Sure, this round of climate change is worse." and comparing that to another change (our coping ability) with no discussion of magnitude.

The degree of climate change is not just "worse". It's without precedent in geologic history in velocity of change. Our improved ability to fend for ourselves is many orders of magnitude less that the degree of change that is happening.

You can read your history books and multiple it by 100 or 1000.

The scale of both differences is unknown. Current rate of climate change is unprecedented. Human civilizational complexity is also unprecedented. There is no way to know what the outcome will be.

Period.

Given that, it would be pretty stupid to preemptively quit.

Nobody's quitting. Recognizing the gravity of our situation is essentially the opposite of quitting.