Musk argued on Monday that people were not having children because they were bad for the environment, and that they should have more children to prevent the collapse of civilization.

Some people think that having fewer kids is better for the environment. It is total nonsense. The environment is going to be fine, even if we double the size of the humans, the CEO told the All-In Summit via video call on Monday.

He said at least maintain our numbers.

Musk didn't give evidence to back up his claims. According to CNBC, Swedish researchers found that having one fewer child per family could reduce carbon emissions in developed countries. Other experts said that a change in lifestyle and pro-climate policies could have a greater impact on the environment than not having children.

Musk claimed that humankind would collapse if people did not have kids.

Musk has expressed concerns about global birth rates before. If people don't have enough children, civility is going to fall, he warned in December. He furthered that argument last week by saying that Japan could exist because of its declining birth rate.

According to the most recent edition of the UN World Population Prospects report, the global population could reach 9.7 billion by the year 2050, from 7.7 billion in 2019.

Insider previously reported that birth rates decline during economic downturns. Many Americans put off having babies because of the soaring cost of living. In Japan, people blame the high cost of having children, restrictive immigration policies, and gender inequality for the population decline.

Many people hold back on having children because of the environmental impacts of overpopulation. Some people are not wanting to have children or have fewer babies so there will be less strain on the environment.