UNITED NATIONS — The United Nations forecast on Thursday that the world’s population will increase from 7.2 billion today to 8.1 billion in 2025, with most growth in developing countries and more than half in Africa. By 2050, it will reach 9.6 billion.
India’s population is expected to surpass China’s around 2028 when both countries will have populations of around 1.45 billion, according to the report on ‘‘World Population Prospects.’’ While India’s population is forecast to grow to around 1.6 billion and then decline to 1.5 billion in 2100, China’s is expected to start decreasing after 2030, it said.
The report found global fertility rates are falling rapidly, though not nearly fast enough to avoid a significant population jump over the next decades. In fact, the UN revised its population projection upward since its last report two years ago, mostly due to higher fertility projections in the countries with the most children per women. The previous projection had the global population reaching 9.3 billion in 2050.
John Wilmoth, director of the Population Division in the UN’s Department of Economic and Social Affairs, said the projected increase will pose challenges but is not necessarily cause for alarm. Rather, he said, the worry is for countries on opposite sides of two extremes: countries, mostly poor ones, whose populations are growing too quickly, and wealthier ones where the populations is aging and decreasing.
The report found that most countries with very high levels of fertility — more than five children per woman — are on the UN list of least developed countries. Most are in Africa, but they also include Afghanistan and East Timor.