We need to progress in our space travel. We've pretty much doomed this planet, in terms of the environment (read somewhere that even if we were to stop all carbon emissions today, excess amounts of CO2 would be in the air for thousands of years). We also kill of species we need faster than they can reproduce. And, we destroy our oceans (where 90% of our oxygen comes from, with phytoplankton). We need to take what we did wrong here, learn from our mistakes, and somehow inhabit a new, fresh planet- and[i] not [/i]do what we did here. The thing about humans is that were made to last. Our survivability, intelligence, and will to go on is why we are the dominant species of the planet. At times, during past mad extinctions, there were estimated less than 70 humans on the face of the Earth. Yet, we bounced back, and here we are. We're just to arrogant to see what we've done wrong. We can't admit we messed up. So as soon as we get our act together, then I beleive we can survive thousands of more years. This is assuming we don't all kill each other in the next 100 years or so.