Overpopulation.

Earth is quickly becoming overcrowded as our population continues to explode. In short order, the demands of this bulging mass of humanity will outstrip what our beleaguered planet can provide. Then things will get ugly fast.

The solution here is pretty simple. Mandatory, reversible vasectomies to every male child born, starting today. This will solve:

Overpopulation.
The futility of abstinence education.
Trapping someone into a relationship with an "accidental" pregnancy.
Orphans (except the dead parents kind).
Those sense-raping commercials for NuvaRing®.

And perhaps most importantly, unprepared, unwilling, and incapable parents. You can still have kids. You just need to pass a test. This will be a simple test. A straightforward test. It will be as follows:

Do you want a baby?
Why do you want a baby?
Do you know what to do with the baby once you get it? Please elaborate.
Are you going to give your baby a terrible name (e.g., something you can buy or eat)?
Are you going to pass your prejudices, ignorance, and anger on to your baby or will you instead attempt to make it a better person than you?

If you can pass this test, you will get your vasectomy temporarily reversed (or sperm donor, etc.).

This will solve everything until the population shrinks to endangered species size.

Of course, this will create a small problem with Catholicism. This will be easily solved by electing a Pope that doesn't hate fun.