Declining birth rates and an underpopulated world are civilization's greatest threats, said Tesla and SpaceX CEO Elon MuskElon Reeve MuskThe Hill's Morning Report - Democrats sense opportunity with SCOTUS vacancy Musk says 'Canadian truckers rule' ahead of drivers' protest over COVID-19 vaccine mandate On The Money — Economy had post-recession growth in 2021 MORE.
"I can't emphasize this enough: There are not enough people," Musk said during The Wall Street Journal's CEO Council Summit on Monday. "One of the biggest risks to civilization is the low birth rate and the rapidly declining birth rate."
During the conference, Musk appeared on a video call from a new Tesla factory. He was answering a question from a journalist about his proposed Tesla Bot, a humanoid robot that could be a substitute for human labor.
This is the second time this year that Musk has referenced declining birth rates across the world. In July, the entrepreneur tweeted a Wall Street Journal article about population decline and raised his concerns about the news.
"Population collapse is potentially the greatest risk to the future of civilization," he wrote.
Population collapse is potentially the greatest risk to the future of civilizationhttps://t.co/VVN8kElTlS— Elon Musk (@elonmusk) July 27, 2021
Globally, the birth rate has fallen from 3.2 average births per woman in 1990 to 2.3 in 2020, according to the 2021 world population data sheet.
The world population, currently 7.8 billion, is expected to peak at around 9.7 billion by 2050 but decline to 8.8 billion in 2021, researchers predicted in a report published in the journal The Lancet.
In the U.S., birth rates have fallen for the past six years, with 1,637 births per 1,000 women. The 2020 U.S. census showed the population in the country climbed just 7 percent from 2010 to 331 million people, which was short of expectations.
Musk, who is building spacecraft capable of transporting people to other planets, believes Earth's declining population is often overlooked.
"So many people, including smart people, think that there are too many people in the world and the population is growing out of control," he said at the conference on Monday. "If people don't have more children, civilization is going to crumble. Mark my words."