Transhuman Space 2110, 2130, 2200

[johndallman]

That's a fairly plausible scenario. There's a problem with its long-term stability in that the teeming masses of Earth are dependent on He3 supplies for the energy to keep their systems running.

They have a vast population to produce ideas and industrial facilities to build them, but there's no obvious reason why they will retain that advantage. Space civilization can create AIs and build more modern industrial facilities.

If Earth's population can be gradually shrunk towards the unsupplemented carrying capacity of the planet, without any major conflicts (bound to be some minor ones) then civilization can embark on another step.