> Habitable planets are the ultimate scarce resource.
Are they? That was once a common belief, but recent results in extrasolar planet searching would tend to contradict it, or at least cast it into serious doubt.
> Once the earth is full we’ll have to find a way to move
Will we? It's quite possible we'll see humanity's maximum population within the next century. Malthusianism didn't really survive contact with modernity; it turns out that most people don't particularly _want_ to have fifteen children, and as countries develop their population tends to become self-limiting. Wholesale emigration off earth feels like a very unlikely solution to population pressure, especially given that society seems to be automatically solving it.
And if we have the energy to lift billions of people off earth, we also have the energy to massively increase population density. Food, in particular, is ultimately largely a question of energy; we typically grow it in fields today, but given super-cheap energy there are other options.
Are they? That was once a common belief, but recent results in extrasolar planet searching would tend to contradict it, or at least cast it into serious doubt.
> Once the earth is full we’ll have to find a way to move
Will we? It's quite possible we'll see humanity's maximum population within the next century. Malthusianism didn't really survive contact with modernity; it turns out that most people don't particularly _want_ to have fifteen children, and as countries develop their population tends to become self-limiting. Wholesale emigration off earth feels like a very unlikely solution to population pressure, especially given that society seems to be automatically solving it.
And if we have the energy to lift billions of people off earth, we also have the energy to massively increase population density. Food, in particular, is ultimately largely a question of energy; we typically grow it in fields today, but given super-cheap energy there are other options.