How do you stand on the "we're part of the environment, so any extinctions we've caused are natural" position? (Even disregarding the fact that we caused extinctions at a vastly greater rate than they've ever come before.) I should add that practical de-extinction has been my dream since I read Last Chance To See when I was a kid. I do think we have a responsibility to the biosphere just as much as we do to the planet in general.
Deconstructing the "natural/unnatural" dichotomy plays a big role in my own personal scientific philosophy. I think it is completely tenable to argue that "we are part of nature so these extinction rates are natural." However, I also believe that because we are have an incredible power over all life on earth, that we also have a responsibility for it. We have a moral imperative to treat the biosphere that allowed for our existence with respect. This happens to also be a prudent position for our species to take since we do not benefit from destroying ecosystems that we directly and indirectly rely on.
That's the position I take. But it's hard to convince taxpayers to fund endangered species-research. Have you read Last Chance To See?