[msm_]

This is technically correct, but I think this misses the point. Unhabitable future Earth with molten icebergs and polluted gray sky may, technically, be a "natural change" and a consequence of "natural" human actions.

But we, humans, want to avoid this future. The same goes for causing extinction of most wild animal species.

Edit: to expand on GP's point: imagine your house burned down, and somebody said "> Your property wasn't destroyed nor hurt in anyway. It just changed". Yeah, all the atoms are still there, but it changed in a way we find undesirable.

[brokenkebaby]

The analogy doesn't work for the nature. It already went through very drastic changes, at least some of them attributed to activities of living organisms, and while it was bad for some species, it was good for others. It's even more so when we're talking about less than cataclysmic changes. It's hard to find any clear logic why disappearance of dodo bird is bad, and e.g. extinction of horses in America is ok.

[leidenfrost]

Global warming will definitely lead to mass extinctions.

But the opposite does not work that way.

Even the most optimistic outcome with the lowest amount of warming, or even none at all, will be accompanied with a drastic change in habitats around the world.