Public discourse on very long-term planning is riddled with inconsistencies. Mostly we discount the future very heavily — investment decisions are expected to pay off within a decade or two. But when we do look further ahead — in discussions of energy policy, global warming and so forth — we underestimate the possible pace of transformational change. In particular, we need to keep our minds open — or at least ajar — to the possibility that humans themselves could change drastically within a few centuries.

Our medieval forebears in Europe had a cosmic perspective that was a million-fold more constricted than ours. Their entire cosmology — from creation to apocalypse — spanned only a few thousand years. Today, the stupendous time spans of the evolutionary past are part of common culture — except among some creationists and fundamentalists. Moreover, we are mindful of immense future potential. It seems absurd to regard humans as the culmination of the evolutionary tree. Any creatures witnessing the Sun's demise 6 billion years hence won't be human — they could be as different from us as we are from slime mould...

Human-induced changes are occurring with runaway speed. It's hard to predict a mere century from now, because what will happen depends on us — this is the first century where humans can collectively transform, or even ravage, the entire biosphere. Humanity will soon itself be malleable, to an extent that's qualitatively new in the history of our species. New drugs (and perhaps even implants into our brains) could change human character; the cyberworld has potential that is both exhilarating and frightening. We can't confidently guess lifestyles, attitudes, social structures, or population sizes a century hence. Indeed, it's not even clear for how long our descendants would remain distinctively 'human'. Darwin himself noted that "not one living species will transmit its unaltered likeness to a distant futurity". Our own species will surely change and diversify faster than any predecessor —— via human-induced modifications (whether intelligently-controlled or unintended), not by natural selection alone...   more »