The extinction of other species really bothers me as they aren't smart enough or strong enough to prevent humans killing them for fun, food, or taking over their environments.
That said I'm not sure it's the world that couldn't support 9 billion people so much as it is our current religious and economic systems couldn't support 9 billion people. There's more food than ever; the problem is distribution.
Absent some sort of mass extinction event (Black Death) human population isn't shrinking so we're going to have to get used to it....
"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming
Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.
| 
