A newborn baby wears a shirt that reads “Baby 8 Billion” in Santo Domingo, Dominican Republic, on Tuesday. The world’s population reached 8 billion that day, according to the World Population Prospects 2022 report released by the U.N. Photo: Ricardo Hernandez/VCG

A student practices her dance moves in Ajangbadi, Lagos in July 2020. Sub-Saharan African countries contribute most to the world’s population increase. UNESCO data shows that 244 million children aged 6-18 are not attending school, of which over 40% of them live in sub-Saharan Africa. Photo: Benson Ibeabuchi/VCG

Central American migrants climb the border fence between Mexico and the U.S. in November 2018. Migration has become the major driver of population growth in developed countries. Photo: Pedro Pardo/VCG

A displaced Ukrainian child sits on a playground beam outside an immigration office in Brussels, Belgium on March 14. The Russia-Ukraine war has forced millions of people to flee from Ukraine to other European countries. Photo: Valeria Mongelli/VCG

Commuters wearing face masks take a subway in Tokyo in January 2021. The declining rates of fertility and increasing level of life expectancy have led to rapid population aging. In 2050, the ratio of people aged 65 or above is estimated to reach 16%. Photo: Yuichi Yamazaki/VCG

A medical worker administers a Covid-19 vaccine to a senior resident near the Christ the Redeemer statue in Rio de Janeiro, Brazil, in January 2021. Photo: Buda Mendes/VCG

Stranded passengers await guidance at a railway station in Guangzhou, South China’s Guangdong province, during the Spring Festival travel peak in February 2016. The harsh snow conditions caused trains to be delayed. China has the world’s largest population with more than 1.4 billion people. Photo: VCG

People celebrate the Spring Festival of Colours in Vrindavan, India on March 17. India is expected to surpass China to become the world’s most-populous country next year. Photo: VCG