Nature is bigger than what you or I think. Even if we did some thing to annihilate our selves, nature would be there to slowly cover over and reclaim what was hers once more, the things we do, only last but a blink and are gone, nature will be here forever and will never truly be beaten...
It is only our vain attempts at what ever we do that we as humans think we can change the world, well if we do, remember, it is only temporary as much as she is concerned.
Yes we can do things to change or effect the here and now, in the long run though, I don’t think it means much except to make a few feel good!!!