Population of all the species are kept in control by other stronger species in the food chain.
Humans are on the higher side of the food chain (and control those that they don't consume .
To control our population, nature has to introduce another stronger animal above us or nature
itself has to unleash its wrath.
Animals of the same species do not kill their own ( some Humans are an exception).
Even if you impose one child policy, the problem will only be delayed not contained.
Adaption will be out of question.
We are turning out to be another pest feeding on nature.
I am not against this, but (accepting reality) am willingly part of this.
(Just my opinion)