According to the United Nations demographer on October 31st 2011, the population topped 7 billion human. But United States Census Bureau’s projections are estimating that even with our increasing number it would take another 4 months after October 31st for the population to reach such an unbelievable amount. This means no one can really know how many people there are in our world, it is simply impossible. Gerhard Heilig, chief of the population estimates and projections section of the United Nations Population Division says “Even the best individual government censuses have a margin of error of at least 1 percent” Even the smallest fraction of a percent difference would be too large to be called the true amount of humans. If the mistake was about 2% then that means the 7 billion people would be wrong by 56 million people!
The global population clock estimates that 255 people are born and 106 perish every minute. The bottom line concluded by the Bureau was that 2 years ago or 2 years from October 31st the world population would have reached 7 billion people. So in the end no one will really ever know but some organizations are close enough to gives us a rough estimate.