The World Population Day is observed on July 11, 2017. It is an annual event which seeks to raise awareness of global population issues. It was inspired by the public interest in Five Billion Day on July 11, 1987, approximately the date on which the world's population reached five billion people. World Population Day was established by the Governing Council of the United Nations Development Programme in 1989
The world population is the total number of living humans on the planet Earth. It is estimated that the population of the world reached one billion in 1804, two billion in 1927, three billion in 1960, four billion in 1974, five billion in 1987, and six billion in 1999. It is projected to reach seven billion in October 2011, and around eight billion by 2025 - 2030. By 2045 - 2050, the world's population is currently projected to reach around nine billion, with alternative scenarios ranging from 7.4 billion to 10.6 billion.
The scientific consensus is that the current population expansion and accompanying increase in usage of resources is linked to threats to the ecosystem. The InterAcademy Panel Statement on Population Growth, which was ratified by 58 member national academies in 1994, called the growth in human numbers "unprecedented", and stated that many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming, and pollution, were aggravated by the population expansion. (With material from: Wikipedia)