This trend suggests that civilization ends with a bang, or a whimper.Population CollapseElon Musk, CEO of Tesla, is concerned about the slowing growth in population.The Wall Street Journal published Monday's alarming report by the billionaire that showed the US population growth rate slowing to a halt.He said that the greatest threat to civilization's future is population collapse. This statement was added to growing concern over stalled birth rates around the world, which could spell disaster.The report estimates that the US population grew by 0.35 percent between July 2019-July 2020. This is the lowest recorded rate, according to the WSJ. This is largely due to the COVID-19 epidemic.AdvertisementAdvertisementSlowing population growth is a risk for the economy if it continues. Economic growth is usually anchored by the growth rates of those in working age.The Journal warned that a shrinking labor force could lead to economic instability in the future, as well as rising inflation and stagnation. However, the Journal warned that a smaller population could lead to a decrease in resources needed to withstand environmental catastrophes.Mars is the New Home of LifeMusk earlier this month had stated that the problem of population collapse is much greater than people realize. However, it was not surprising that Musk wanted to set an example by having a child together with Claire Grimes Boucher.A decrease in population could make it very difficult for humanity, which Musk considers one of his key goals in life, to travel interplanetary.AdvertisementAdvertisementHe said that Mars is in great need of people because its population is currently at zero. The custodians for all other life on Earth, humans are. Let's bring life to Mars!Musk expressed concern about civilization's eventual collapse, pointing out that women have fewer children worldwide than men.Musk tweeted a follow up tweet this month, stating that the trend suggests the former. Economists are more likely to agree.READ MORE: Elon Musk believes that the greatest threat to civilization's future is a collapse in the population [The Hill]AdvertisementAdvertisementMore on population growth: Experts say that the decline in population is turning Earth into a ghost town.