UNITED NATIONS — The world's population is expected to grow by more than 2 billion people in the next decades and peak in the 2080s at around 10.3 billion, a major shift from a decade ago, a new report by the United Nations said Thursday.
The report — released on World Population Day — says the global population is then expected to decline to around 10.2 billion by the end of the century.
John Wilmoth, head of the U.N. Population Division which prepared the report, said the probability that the world's population will peak within the current century is quite high – about 80%.
''This is a major change compared to the United Nations projections from a decade earlier when the estimated probability the global population would reach a maximum, and thus the growth would come to an end during the 21st century, was around 30%,'' he said.
Bucknell University mathematics orofessor Tom Cassidy told AP that newly published research in the journal Demography that he co-authored also calculates that population is likely to peak before the end of the century.
According to the World Population Prospects 2024 report, the earlier-than-anticipated population peak is due to several factors, including lower fertility levels in some of the world's largest countries, especially China, whose population is projected to drop dramatically from 1.4 billion in 2024 to 633 million in 2100.
Globally, women are having an average of one fewer child than they did in 1990, the report said, and in more than half of all countries and territories, the average number of live births per woman is below 2.1. That's the level needed for a country's population to maintain its size without migration.
Nearly 20% of the world — including China, Italy, South Korea and Spain — have ''ultra-low'' fertility, with women having fewer than 1.4 live births, the report said. In China, the current number is just around one birth per woman, Wilmoth said.