The world's population will soon peak and decline sharply by the year 2100.

The researchers calculated that under the current situation, the world's population will peak below 9 billion people in 2046, and then decline to 7.3 billion in 2100. In this case, regional social collapses are likely over the next decades. A shrinking population could also create new challenges, such as a shrinking workforce and increased health care burdens associated with an aging society, as is the case in Japan and South Korea.