The statement "Save the Earth" which is used by some environmentalists, annoys me. The reason I dislike it is because the Earth is in no danger. There is nothing people can do that would damage the Earth beyond it's ability for self repair. They are not saving the Earth. What they're doing is keeping the Earth habitable for humans. We could pollute the world as much as we want and the Earth will continue just fine. We'll have wiped ourselves and countless species of animal/plant life out but the world and life of some type will continue.
Environmentalism is really just keeping the world fit to live in, maintaining our way of living. I'm all for environmentalism. I think we should try and take care of the planet to the best of our abilities so that future generations have many of the things we have. If we don't though life will continue. It's unlikely that even humanity would be wiped out. Sure millions maybe even billions of people may die (depending on what particular calamities occur). People would likely adapt and survive in some fashion. We are a fairly creative species and are capable of altering our environment to suit us at least on small scale. If/when global warming does occur it's not likely to kill off humanity, just a percentage of humanity.