Little Hawk is correct..science could deal with the problem, if people would allow it. There are ways to provide birth control techniques on a large scale, but that is considered interfering with nature or meddling in private matters or 'playing God' or any one of 27 other reasons not to cooperate....and $$$ are ALWAYS involved. Many industries and businesses rely on *growth* (i.e., housing) and would not care to have more dwellings than people.

Sadly, Little Hawk is also correct that population WILL be controlled eventually, even if we make no effort to do it ourselves.
Famine, pestilence, war, riots, pollution can reduce the totals pretty fast. We have seen it happen locally...(Ethiopia, Sudan...etc..) but no one seems to be willing to extend the analysis of the situation to global parameters.
   Not today, not tomorrow...not even in the next 20-30 years(probably).....and most likely not in my lifetime. It doesn't make me feel real confident about the situation in my son's old age, though.

Why can't folks get it thru their skulls that because it has NOT happened, it won't happen? We haven't HAD 20 Billion people before...and we don't know what this Global Warming thing will develop into. What does it take to get people to err on the side of caution?