1240 GMT August 19, 2019
If the new projections hold good, India will also be — or continue to be — far more densely populated than China. India's population density is already more than double that of China's, which has 141 people per square kilometers against India's 382 people per square kilometers, Times of India reported.
How the date moved from 2050 to 2022
India's population ascendancy was first estimated to take place in 2050, then gradually lowered to 2040 and then 2030, said Prof Siva Raju, Chair of the Center for Population, Health and Development at the Tata Institute of Social Sciences in Mumbai.
But the UNA's projections have changed, with China's population growth rate decelerating much faster than India's, which explains why India will top the world's list in 2022.
The two giants, China and India, now have 19 percent and 18 percent of the world's population, states the UN report released on July 29.
China's fertility rates — the average number of children a woman can be expected to bear during her lifetime — have dropped much lower than India's, which is why its population is growing less than India's.
Overall, India had seen an appreciable decline in its fertility over the years to 2.48 from 5.9 in 1951, though that process was faster in China, which had a fertility rate of 6.11 in 1951. India's higher fertility contributed to the higher population growth.
Lastly, the population growth of China in recent years was mainly due to 'population momentum' (the population's total fertility has fallen below the replacement level since the early 1990s) and this will also contribute to the population growth in India for the coming decades.
Over the last decade, from 2001-2011, India's population grew at only 1.64 percent per year against 1.96 percent in previous decade.
In May, Health Minister J.P. Nadda said India's population would cross China's by 2028. He cited the UNA's 2012 Revision.
However, he defended the government's population control measures, which lowered the decadal growth rate from 21.54 percent for 1991-2000 to 17.64 percent during 2001-11.
Some experts believe that the UNA's revised estimates are just projections, which may or may not materialize. India's population will certainly overtake that of China's, but the exact year could vary.