It's a triangle: prosperity, sustainability, population. Choose 2 (and obviously if you don't choose sustainability the sh*t is going to hit the fan at some point anyway).
The key issue is the global population.
(Edit: We're discussing life on this planet. Colonising space obviously means that human population may continue to grow, but not on Earth and not using Earth' resources)
It's a triangle: prosperity, sustainability, population. Choose 2 (and obviously if you don't choose sustainability the sh*t is going to hit the fan at some point anyway).
The key issue is the global population.
(Edit: We're discussing life on this planet. Colonising space obviously means that human population may continue to grow, but not on Earth and not using Earth' resources)