World Population Day is observed on July 11 every year to raise awareness of global population issues. Overpopulation has become a critical concern as the world's resources are being used up at an unsustainable rate. The major purpose of World Population Day 2022 is to raise awareness of all the negative impacts that population growth has on the steady development of nature. 
The event was established by the Governing Council of the United Nations Development Programme in 1989. The day was suggested by Dr. K.C.Zachariah in which population reached five billion when he worked as Sr Demographer at World Bank. K. C. Zachariah was a Honorary Professor at the Centre for Development Studies, Thiruvananthapuram, Kerala.
Theme of World Population Day
The theme of World Population Day 2022 is 'A World of 8 billion: Towards a resilient future for all- Harnessing Opportunities and ensuring rights and choices for all'. The theme for World Population Day 2023 is “Unleashing the power of gender equality: Uplifting the voices of women and girls to unlock our world’s infinite possibilities.”
World Population Trends
It took hundreds of thousands of years for the world population to grow to 1 billion – then in just another 200 years or so, it grew sevenfold. In 2011, the global population reached the 7 billion mark, it stands at almost 7.9 billion in 2021, and it's expected to grow to around 8.5 billion in 2030, 9.7 billion in 2050, and 10.9 billion in 2100.
Further Reading