His post made me wonder whether ethics is really just about taking others' interests into account. I'm pretty sure pristine environments don't have interests, but wouldn't it be wrong to pollute them, even if no-one's interests were harmed?
Like "logicnazi" in the comments, I'm inclined to simply respond "NO". It's a view I do hear occasionally, but I'm at a loss as to why anyone would hold it. I'm hoping someone might leave a comment here defending the view.
The idea that the environment has intrinsic value strikes me as so unmotivated that I'm not sure how to argue against it. But perhaps an example could help illustrate. Suppose that in the future, all sentient beings live on the moon, so as to preserve the pristine natural environment on Earth for pleasurable holiday tours and such. Now, an interstellar "trolley" comes hurtling towards the moon, with a massive nuclear bomb on board that will kill us all. But we can pull a lever that will change its course so as to impact Earth instead, wiping out all the plant life there. These are the only two options: wipe out all sentient beings, or else the natural environment. Which should you do?
Well, obviously we should let the plants die rather than us. But that's still consistent with the plants having some intrinsic importance, albeit less than us. But I want to make a stronger claim. I claim that there is no reason at all to oppose pulling the switch. It is certainly bad that people will never again have the pleasure of experiencing the natural environment. But this result is guaranteed to happen either way: whether by the plants dying, or by all sentient creatures dying instead. Once all the conscious beings are dead, the beautiful environment has no value, for there is no-one left to experience it. So there is nothing at all to be said in favour of letting the plants live, in this situation. If you share this judgment, then we have established that pristine environments have merely instrumental value. If your intuitions differ, I really don't know what else to say...