Given that most complex life is probably carbon based, and given the one planet with complex life we can observe, my guess is that most complex life runs into o

Given that most complex life is probably carbon based, and given the one planet with complex life we can observe, my guess is that most complex life runs into one of two paths: 1. You don't have enough easily accessible hydrocarbons in ground to build a civilization advanced enough to even get you into space. 2. You do have enough hydrocarbons which leads to inevitable overshoot, and accompanying collapse before you ever get close to figuring out interstellar travel. Exponential growth patterns lead you to either exhaust the carrying capacity of your planet, or you end up warming your planet too much and die off (or a little bit of both). We're a pretty good case study between 1 and 2. Right now we're in a race to see if we can exhaust our hydrocarbons or overheat our planet first, there seems to be no realistic alternative (plenty of nice fantasy ones though). If we had reached peak oil in the early 80s (or sooner) we would have likely avoided catastrophic climate change, but would have started a major population shift downwards towards 1 billion, where we would have likely stabilized but with no major technical progress (technological progress is largely a function of energy). We didn't though, so now it seems like we are going to continue to increase the rate we combust hydrocarbons until we create an unlivable planet (at least for us). A few billionaires are making some cool toys, but we don't seem to be able to survive until we're anywhere near interstellar travel.