Generally, a carbon neutral world would be a benefit, regardless of the effects on climate change. We'd ensure the sustainable operation of the planet - regardless of how many of us there are - because we'd be maintaining the earth's resources in their current balance. Right now, we're converting a good chuck of them from one form to another, which eventually - even if this isn't true now - will have some sort of repercussions.

That being said, being completely carbon neutral is pretty much impossible given the way our world is currently set up.