Effective means for population control?

Question

Exponential population growth has an extremely negative effect on the environment

There have been some countries that have effectively reduced there population including Iran

What are some possible ways to reduce the growing population?
both the extreme and plausible

Answer 1

Well, China has the one-child law, but that intrudes very much into people's personal lives. If we used that in the United States, the abortion issue would be more controversial than ever.

We could make birth control more available and research ways to improve its effectiveness. From what I hear, the pill is the most effective, but condoms are the most widely available. Maybe we should be investigating ways in which to make condoms more durable, since a lot of pregnancies happen because "the condom breaks."

Answer 2

AIDS is the best one made so far...