It doesn't care about us, and we don't need to "care" for it, it's going to be fine without us. What we don't do is care for ourselves, which is what you're really saying, self-preservation. The earth doesn't give two shits if it's 50 degrees warmer. You can't even say it's to protect life, because some forms of life will do way better in a warmer planet too. The universe / nature is gnarly already, much more than we can ever be, and plus, whatever we do, we're nature too. So in a way you're saying nature doesn't care for itself.