Even if you reach that point, you're likely now at the age where fertility problems become a real issue.

If you want to have kids do it when you're in your early 20s.

This is factually false :) and if you’re really worried, there are many options available to you to preserve what you will need or consider adoption - there are so many humans being born without a family after all.

Most people I know realize they should have had kids sooner once they have them. Adoption is also not that easy, there are plenty of cases where adoption causes kidnapping.

How does adoption cause kidnapping?

Birth parent has regrets and wants "their" kid back?

I agree with you on a factual basis, but you understand that a large amount of people have a deep emotional instinct to not be ok with those options, right?

Indeed, that’s what I mean by raising awareness. It takes time to change such deeply rooted beliefs. I think if humans are to prosper and resolve planet-wide challenges like global warming, we need to be better at managing resources and we need to work together as a species, not separate counties fending for themselves.

Well, I'm not sure I agree with convincing people to not feel this way, but its admirable that you are putting in effort to change the world in a way that fits your morals

This sort of "hurry up or it'll be too late" attitude is a great way to figure out that you don't want to have kids after it's too late to make that choice.