H'm, now it sounds like by "good for the environment" you didn't necessarily mean anything that you would consider good for anything at all, but just what a fairly unreflective person off of the street would mean by "good for the environment" in that context. In that case, I agree that the absence of humanity would be "good for the environment", although I don't particularly care what's "good for the environment", which is merely an instrumental value that would largely no longer apply. (That's just me, however.)

So thanks for explaining!