maybe people could try not having sex until they're ready to have children.

So the solution is for other people not to have sex? Even in cultures where pre-marital sex is grounds for being stoned to death; they still have sex.

I'm guessing this *can't* work, we're just not wired for it, probably has something to do with Millions of years of Evolution.

If you want a seriously radical solution that could (in theory) work...

Birth Control Implants in all women ages 13 and up.