Yes, it seems impossible to kill everything. Even the asteroid that wiped out the dinosaurs didn't wipe out all the dinosaurs; the survivors are today called birds. With all the extinctions and global disasters that have happened, Nature never had to start over from scratch; there was always something left alive.<quoted text>
You know, caveman, I don't think it really matters whether or not we do anything to mitigate human induced global warming - or if we even can if we try. Nature will not allow humans to render the planet unfit for life, or even go so far as rendering it unfit for human life. No. Nature will kill 95 percent of us first. Even if we make a big enough natural catastrophe to do that, there will still be over 15 million Americans - about the same as the Native American population in 1492.
What matters is the suffering and pain along the way. Doesn't matter to an ephemeral and symbolic Mother-God like Nature; pain and suffering are two of her most common attributes. But as humanists or theists, we feel an obligation to try to reduce pain and suffering. So even if the Earth has its human infection in remission for a while, it will be nasty and brutish for the humans.
The Earth probably won't die until the Sun is in its death throes.