Tom is right. The Earth is a tough old girl. Theres more than enough time before our Sun burns out. The odds of us surviving ourselves look pretty low, though. Too much consumption, little thought to the future and far too little concern over anthropogenic environmental impact. This isn't going to end well for humankind, and I'm not even sure if forward momentum can be stopped. Nations are so busy looking out for their own better interests that the thought of cooperation on a truly global scale only exists in dreams like Star Trek. Do you really think the elite will survive their own shortsightedness? I'd love to see a way out of this mess but it seems to me we've made our beds... forward momentum will have it's way. Like in The Offspring's song "Genocide" we'll make ourselves extinct