What the global population will look like in 2100

We’re just 44 years away from “peak human” — when the world’s population will begin to decrease, according to new projections published in The Lancet.

Breaking it down: By 2100, the populations of China, Japan and Italy are expected to be half of what they are today, while sub-Saharan Africa will be home to three times as many people.

• This forecast puts the global population in 2100 some 2 billion below the UN’s estimate of 11 billion, with the peak also expected much sooner.
• It factors in greater decreases in fertility rates due to increased access to education and contraception.
• Immigration patterns and climate change will change the outlook, the authors note.
• As birth rates fall and life expectancies climb, the world's population will get much older.

The big picture: The global population rose over the last 80 years from around 2.3 billion to 7.8 billion. If that rate of growth continued for another 80 years, it would rise to 26 billion by the turn of the next century.

• Instead, if these forecasts hold up, we’ll be on the downslope from the global peak.

Worth noting: Some of the spikes projected in Africa by 2100 are mind-boggling. Niger's rise from 21 million to 185 million is like starting with New York state and then adding California, Florida, Illinois, Pennsylvania, Ohio and Texas, plus all of Canada, over the course of 80 years.