I don't need to propose an alternative in order to state that the imposed one child policy is evil, along with its forced abortions and forced sterilizations.
Second, you can't prove overpopulation is as serious as the government claims, nor can you prove their "solution" fixes it.
Third, if it is as serious as is claimed, it will affect the world (anthropogenic environmental impact, immigration, etc...), so it's everyone's worry.