>I think Lee Daniel Crocker is quite right in pointing out that we have few
>clues how to maintain a biosphere capable of supporting a human society
Yes, but the premise of the discussion, here, is that the Earth is becoming immanently uninhabitable (post assembler) in who knows how many ways, else why leave in such a rush? So: given not much choice, would you bet that we can't figure it out? With Advanced nanotech to pry into the minuscule eco-details and also to manipulate them?