World Population Day is an annual event, observed on July 11, which seeks to raise awareness of global population issues. The event was established by the Governing Council of the United Nations Development Programme in 1989. 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. A large population means a large demand for everything and subsequently affects global warming, deforestation, starvation, pollution and related issues. To avoid these catastrophes we should check our population growth and reduce resource consumption.

History tells us that world population grew slowly at the very beginning and then at faster rate. It took million of years to reach the level of 230 million at the beginning of the Christian era. It again touched 545 million in 1650 and 1 billion in 1830 A.D. the population rose from 1 billion to 2 billion in 100 years i.e. from 1830 to 1930 and in subsequent 30 yrs to 3 billion i.e. from 1930 to 1960 and another 15 years to 4 billion i.e. from 1960 t0 1975. Around 5 billion was achieved in only 12 years i.e. from 1975 to 1987. At present world population is 6,602,244,175 adding by another 76 million people to the volume of world population per year. According to UN report the world will add another 2.6 billion people by 2050. At present global growth rate is 1.17% which is too high to make a stable population

The world population is the total number of living humans on Earth at a given time. As of January 2009, the world's population is estimated to be about 6.75 billion. According to population projections, this figure continues to grow; the 2008 rate of growth has almost halved since its peak of 2.2% per year, which was reached in 1963. World births have levelled off at about 134-million-per-year, since their peak at 160-million in the late 1990's, and are expected to remain constant. However, deaths are only around 56 million per year, and are expected to increase to 90 million by the year 2050. Since births outnumber deaths, the world's population is expected to reach nearly 9 billion by the year 2040.

World Population Day 2010 theme is 'Everyone Counts' This year World Population Day highlights the importance of data for development. The focus is on the 2010 round of the population and housing census, data analysis for development and UNFPA’s lead role in population and development. Reliable data makes a difference, and the key is to collect, analyze and disseminate data in a way that drives good decision making. The numbers that emerge from data collection can illuminate important trends.