I try to stay as positive about it as I can, and if we all cared, the Earth could "heal" itself again over time. But in a way, we already ruined it. If people want to be consumers, than we will trash the planet sooner than later.
That reminds me, I wrote this on my blog if your're interest. It kinda deals with a similar topic:
Oh really? I would have loved to see that. I joked to my sister that she would have to take me again when it snows. I wanted to see the mountains again, but I know how difficult that would be with the roads and all.