In 1798, there were about a billion people in the world and economist Thomas Malthuspredicted that overpopulation would lead to war and famine.  In 1968, at 4 billion people, experts published The Population Bomb and The Limits to Growth and predicted the same thing.
Today, in 2014, there are over 7 billion people on the planet.  Nevertheless, global poverty and violence are at all-time lows.  Even carbon emissions are dropping (at least in the US).  It seems the that experts were mistaken.