Enzyme...
...has put an intelligent point forward.

But the problem is that we have no timescale for when these technologies will become commonplace (or even feasible). Commercially generated energy from nuclear fusion is probably 75 years away. There are ethical issues surrounding GM oganisms (although I suspect that the use GM bacteria being used to produce oil from plant matter will happen quickly) which could delay development by decades.

However, the growth of the world population continues unabated. I suspect it would take some form of calamity to stem growth.
(Bicycle Repairman "you're also a bit of a wanker", Fri 9 Jan 2009, 10:59, Reply)