I'm all in favour of environmentalism; the Earth has a vital and intricate ecosystem that I don't believe we fully understand and yet feel comfortable screwing with in many and sundry ways. But let's be honest here. There is no need for environmentalism on the moon. The Moon is Dead. Dead. There is no life up there, at least none that we've ever found (and we've certainly explored it more than we have Mars). I can see the value in keeping some of Mars intact and in carefully checking for indigenous life, but the Moon is dead. Period. The only way there will be life on the moon is if we put it there. Environmentalism is not needed where there is no environment. Heck, there isn't even an atmosphere to pollute. If anything I'd say that the sooner we get as many people up there as possible, the better, because it'll help alleviate conditions here on Earth, where there really is life and it really is being threatened.