War for a greener planet?

I am, for the most part a pacifist. Physically anyway. Don't get me wrong, if insulted the words from my mouth and glares from my eyes spew ammo faster than any machine gun could. But I don't like physical confrontation, including war.

I have been, for the most part, opposed to the wars of America. But today I had a thought. Much like the myth that lemmings jump off cliffs to maintain a reasonable population, perhaps war is necessary to reduce the ever-rising human populous. 

I don't like the idea of soldiers dying. I don't. But what I also do not like is the idea that the world is dying. It is dying because 6 billion people and their economies persist on infringing on land, overusing water, dumping loads of carbon while not replacing it, etc. 

Human reproduction laws seem both unjust and unenforceable. Killing each other, is for the most part illegal. But war. That's one way we can unload some of the strain on the planet.

Or, you know, we could live sustainably, but that's out of the question; this is America after all.