When there isn't enough resources for everybody, chaos ensues. You saw what happened in New Orleans after Katrina. And what happens in bad neighborhoods. People will hurt or even kill people to get what they need to survive. And when the global population is so great that the resources of the world can't support it, the same thing will happen.

What can we do to prevent this from happening? Well, there's a limit to what Mother Nature can provide for people. We can't increase that, unless we look to expanding production. But production takes the lives of other animals. And even if we do that, earth is only so big- we'll be forced to stop expanding at some point.

The only real solution is to stop reproducing so quickly. Seven billion people!? People are already complaining about how oil isn't being produced quickly enough to suit humanity. Eventually, more and more resources will end up just like oil. And eventually, they'll become scarce. We just won't be able to support people anymore!

If we slow the growth in population, the longevity of the human race will increase. If we slow the growth in population, we will have more time before such chaos ensues.

Ideally, if we prevent the forthcoming of people, we will want to choose to prevent the worst people from coming to be. But how can we judge beforehand what the child will be like? The only hints we have are the conditions surrounding the new child. If the parents see that the child would be raised in an unsuitable environment in which the child would grow to be heavily flawed, they abort the child. In doing so, they are preventing what they see as a life that would grow to be troubling and problematic for the child itself and for the world around it. This controls the growth of the population, therefore increasing the longevity of the earth, and it tends to help keep the world ridden of low-lived people.

This is why abortion is good for society.

And don't give me "Jesus says so" as a counter-argument.