World Population

The world population is the total number of humans on Earth at a given time. In February 2008, the world's population is believed to have reached over 6.60 billion. In line with population projections, this figure continues to grow at rates that were unprecedented before the 20th century, although the rate of increase has almost halved since its peak, which was reached in 1963, of 2.2 percent per year. The world's population, on its current growth trajectory, is expected to reach nearly 9 billion by the year 2050.

Censuses taken between 300–400 AD showed over 50 million people living in the combined eastern and western Roman empire.(citation Dr. Kenneth W. Harl, tulane.edu)

Below is a table with historical and predicted population figures shown in millions. The availability of historical population figures varies by region. Please see World population estimates for more figures.

Different regions have different rates of population growth, but in the unusual case of the 20th century, the world saw the biggest increase in its population in human history due to medical advances and massive increase in agricultural productivity made by the Green Revolution.

In 2000, the United Nations estimated that the world's population was then growing at the rate of 1.14% (or about 75 million people) per year, down from a peak of 86 million per year in 1987. In the last few centuries, the number of people living on Earth has increased many times over. By the year 2000, there were 10 times as many people on Earth than there were 300 years ago. According to data from the CIA's 2005–2006 World Factbooks, the world human population currently increases by 203,800 every day. The 2007 CIA factbook increased this to 211,090 people every day.