World population milestones, such as reaching particular population counts, have been unnoticed until the 20th century, since there were no reliable data on global population dynamics. [2]
It is estimated that the population of the world reached one billion for the first time in 1804. It would be another 122 years before it reached two billion in 1927, but it took only 33 years to rise by another billion people, reaching three billion in 1960. Thereafter, the global population reached four billion in 1974, five billion in 1987, six billion in 1999 and, by some estimates, seven billion in October 2011 with other estimates being in March 2012.[3] It is projected to reach eight billion by 2025–2030. According to current projections, the world's population is likely to reach around nine billion by 2045–2050, with alternative scenarios ranging from a low of 7.4 billion to a high of more than 10.6 billion.[4] Projected figures vary depending on underlying statistical assumptions and which variables are manipulated in projection calculations, especially the fertility variable. Long-range predictions to 2150 range from a population decline to 3.2 billion in the 'low scenario', to 'high scenarios' of 24.8 billion. One scenario predicts a massive increase to 256 billion by 2150, assuming fertility remains at 1995 levels.[5]
Population (in billions) |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Year | 1804 | 1927 | 1960 | 1974 | 1987 | 1999 | 2011 | 2027 | 2046 | |||||||||
Years elapsed | –– | 123 | 33 | 14 | 13 | 12 | 12 | 16 | 19 |
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There is no estimation for the exact day or month the world's population surpassed each of the one and two billion marks. The days of three and four billion were not officially noted, but the International Database of the United States Census Bureau places them in July 1959 and April 1974.
The Day of Five Billion, 11 July 1987, was designated by the United Nations Population Fund as the approximate day on which world population reached five billion. Matej Gašpar from Zagreb, Croatia (then SR Croatia, SFR Yugoslavia), was chosen as the symbolic 5-billionth concurrently alive person on Earth. The honor went to Zagreb because the 1987 Summer Universiade was taking place in the city at the time.[6][7]
The United Nations Population Fund designated October 12, 1999 as the approximate day on which world population reached six billion following the birth of Adnan Mević, the first son of Fatima Helać and Jasminko Mević, in Sarajevo, Bosnia.[8] It was officially designated The Day of Six Billion.
Demographers do not universally accept this date as being exact. In fact there has been subsequent research which places the day of six billion to be nearer to June 18 or June 19, 1999.[9] The International Programs division of the United States Census Bureau estimated that the world population reached six billion on 21 April 1999.
Adnan Mević, born in Sarajevo, Bosnia-Herzegovina, 12 October 1999, was chosen by the United Nations as the symbolic 6 billionth concurrently alive person on Earth.[8] He is the first son of Fatima Helać, 29, and her husband Jasminko Mević. The child was born weighing 3.5 kilograms in the Koševo hospital in the capital of Bosnia and Herzegovina. He had been proclaimed by the United Nations Population Fund and welcomed by the secretary-general of the United Nations, Kofi Annan, as the six billionth baby. He was born on the designated day two minutes after midnight.[10]
The "Day of 7 Billion" was targeted by the United States Census Bureau to be in March 2012,[11] while the Population Division of the United Nations suggested 31 October 2011, [12] and the latter date has been officially designated by the United Nations Population Fund (UNFPA) as the approximate day on which the world's population reached seven billion people.[13] United Nations Secretary General Ban-Ki Moon is to speak at the United Nations building in New York City on this new milestone in the size of world population and the issues that it will raise, along with promoting the UNFPA's new program named 7 Billion Actions,[14] which will seek to: "[build] global awareness around the opportunities and challenges associated with a world of seven billion people" and inspire individuals and organizations to take action.[15]