I won't be long-winded. Fortunately several posters already have already expressed the reality of the situation far better than I could. Humans have a very, very limited capacity for comprehending their place in the multi-billion-year history of this planet. The idea that we are so fantastically important in the evolutionary flow here on Earth is especially prosaic. It illustrates a basic arrogance; that somehow our species is so powerful that our minute changes to the environment will really make a difference 1 million years from now (which I think everyone on this board understands is but a wink of the eye in geological timescale). The truth is that our lifeform is not especially well adapted to a long-term stay on the terra-ball. I think that the mammalian big brain is turning out to be a not-so-desirable trait, and will simply become an evolutionary dead-end. From a purely selfish, protectionist point of view, your concern that humans and other organisms may be undergoing some extremely painful near-term adjustments because of human activity is probably true. Where I disagree with you is that these events are somehow "un-natural", or that from a geologic timescale point of view that they are significant. My best guess is that in 1 million years hence (or so) there will be no trace of human civilization on Earth, and that evolution will have continued on its merry way; after all, thousands of species have reached their climax and passed unceremoniously into extinction. Isn't it pure arrogance to think that our species will be any different?