Guardian: WORLD population is projected to reach seven billion early in 2012, up from the current 6.8 billion, and surpass nine billion people by 2050, reveals the 2008 Revision of the official United Nations population estimates and projections. In July 2009, the world population will reach 6.8 billion, 313 million more than in 2005 or a gain of 78 million persons yearly. Assuming that fertility levels continue to decline, the world population is expected to reach 9.1 billion in 2050 and to be …