San Francisco, Jun 22 (IANS): Tesla CEO Elon Musk's grim forecast of humanity suggests that a "population bomb" would lead to a worldwide collapse in humans in the coming decades and everybody would start to see the evident effects by 2050.

Musk's prediction was triggered by a tweet from a page called World of Engineering that said: "1950 (historical) world population - 2,556,000,053. Current world population - 7,712,343,478. 2050 (projected) world population - 9,346,399,468."

Replying to that tweet on Friday Musk wrote: "Real issue will be an ageing and declining world population by 2050, *not* overpopulation."

Musk also shared a Wikipedia link to an article titled, "Projections of population growth".

"Yes, demographics, stratified by age, will look like an upside down pyramid with many old people and fewer young," the multi-billionaire entrepreneur wrote further.

The SpaceX CEO's theory believes that when an increasingly-elderly global population clashes with declining birth rates around the world in the near future a 'population bomb' would go off, web portal Futurism reported.

Musk first broached the topic back in 2017 when Musk replied to a publication saying, "The world's population is accelerating towards collapse, but few seem to notice or care."