But it's his optimism which counts (Score 1)

The problem with the article is perhaps that Clarke is happy to make the assumption that the various the problems mentioned in the original post (misery, starvation, all the usual suspects) will be eliminated by the technological advances. This certainly hasn't been the case this century and I don't think it is justifiable to claim the next century will be any different.

OTOH it is great that the ideas he mentioned are even conceivable in the time scale given - They might not a panacea, but that doesn't stop them being pretty cool... :o)