FWIW, if you care about the environment, the right move is to have kids. All species expand to fill their ecological niche. If you abstain from having children, their spots will just be taken up by other people's children. We are powerless to influence the number of people, but we can influence the proportion of people who have an environmentalist bent.

I hear you about the career thing. I have sacrificed immensely to be able to afford a family. But now, when I am surrounded by my children, I think about all of the possibilities that lay ahead of them, all the grand adventures they will have and the adversities they will overcome, and I remark to myself, "I made all of this possible".

> FWIW, if you care about the environment, the right move is to have kids.

This couldn't be more wrong. Every new life is another body consuming resources.

> All species expand to fill their ecological niche.

This doesn't apply to humans. Unlike other animals, we've mastered agriculture and can produce our own food. But there are still non-renewable resources that we're constantly consuming and will eventually run out of, but we'll continue to reproduce.

> If you abstain from having children, their spots will just be taken up by other people's children.

This implies the inverse, that if I choose to have children, someone else will react by choosing not to. If I choose not to, that won't cause someone else to have more to "take up my spot". There will still be fewer children.

> We are powerless to influence the number of people

On an individual scale, yes. My choice to not have children has no significant impact on the population. But lots of people choosing to not have children does. Your argument is similar to the one made by people who don't vote because they think their one vote won't change the outcome of the election.

> but we can influence the proportion of people who have an environmentalist bent.

This part is at least true.

The thing is that, after you decide to not have kids, time keeps up it's inexorable march. The earth has a carrying capacity for humans. We haven't hit it yet. But we will. This is the one absolute of life: species expand in population until there's no more niche left to occupy.

So after you decide not to have children, other people will have children. Eventually, their descendents will take up the space in the earth's carrying capacity that your descendants would have taken up. There is nothing you can do to stop this. So the best strategy is to change the proportion of people who have an environmentalist bent. Children are an effective way to accomplish that.

Umm... at the risk of being dramatic..

In addition to worrying about the carbon footprint of another kid, I have a much bigger concern that

* We will do nothing regarding climate change (seems likely)

* The predictions for Business as Usual will have been too conservative (seems likely given that the Arctic is melting well ahead of schedule, and who knows how clathrates pan out)

* Temps rise by a good 8C or so in the next 8 decades

* My child, or their children, will die horribly in a new global Holodomor as our resource chains (webs, really) collapse and the world's civilizations implode.

Anyway, I already had one. But I have a deep, pervasive dread that I have doomed them to the above. However, I also might be wrong! Maybe it just gets a bit warmer and they can open a nice winery in Sweden and it's all fine.

Let your kids worry about that. I know I, personally, would rather be alive and facing catastrophe than not be alive. And history is filled with examples of people who persevered through all kinds of calamity. We're a resourceful bunch. And it'll be easier for your children to face the future together than for your child to face it alone.

Just checking in to say I sympathize. I don't have any kids yet, and was thinking about having none (not having a kid is as effective as being vegan and biking to work for the rest of your life...). But I'm worried about how my life would look with and without kids and how hard it would probably be to convince my future spouse to not have kids, etc. And in light of that I start feeling helpless and maybe it's worth just having a kid and enjoying my life because it's not my fault that so many people are fucking up the environment, driving trucks on hour long commutes, and having 5 kids. ¯\_(⊙︿⊙)_/¯

Population stability is probably the metric to optimize for if you care about sustainability. Rapidly growing or shrinking populations cause problems.

Given how much the West flirts with the replacement rate, I think you should do whatever you feel like doing.