We calibrate how much effort should be put into mitigating the risks of nanotechnology by asking what observations should make us update the likelihood we assign to a grey-goo scenario. We approach mitigation strategies from an engineering mindset rather than a political one.

I think it's fair to say that the danger of grey goo is greater now than it was in the 1980. How well do the engineering mindset work for the problem.

On the other hand when it comes to overpopulation political solutions such as the Chinese one do massive amounts of progress.

1: By carrying capacity, I mean finite resources such as easily extractable ores, water, air, EM spectrum, and land area.

Given that some people use up no EM spectrum at all, it can be confusing to speak of something like it as "carrying capacity". We tend to use a lot of recourses because we can and not because we have to.

Advocating for population control the way the Chinese do is politically unpopular and population control isn't easy. Cutting resource consumption the way enviromentalists propose seems to be easier.

Bill Gates journey is also interesting for this question. He started his philantrophic efforts by focusing on reducing population growth. Given that empowered working woman don't tend to get more than two children he switched the focus of his efforts.

That's why Bill Gates fights malaria. It's also the cultural background in which GiveWell recommends funding more bet nets and improving local economies through direct money transfers. It's no accident that the effective altruist crowd doesn't focus on reducing population. It's certainly not because they are not smart enough to think of ways to do so that don't involve Chinese style policy tools.