No one is confusing the two because “saving the planet” is always meant as in “saving the planet as a hospitable environment for humans and/or animals” (a bit of a mouthful, no?). Literally no one cares about the rock called the Earth for its own sake.
You might as well go and argue that some particular person from Africa can't be called “black” because his skin pigmentation is brown. That's equally productive.
You might as well go and argue that some particular person from Africa can't be called “black” because his skin pigmentation is brown. That's equally productive.