Shanna Swan, an environmental and reproductive epidemiologist at Icahn School of Medicine at Mount Sinai in New York, warns that the impending fertility crisis poses a global threat comparable to that of the climate crisis.
“The current state of reproductive affairs can’t continue much longer without threatening human survival,” she writes in Count Down.
Sperm counts in the west had plummeted by 59% between 1973 and 2011. Now, Swan says, following current projections, the median sperm count is set to reach zero in 2045.
Such is the gravity of the threats they pose, she argues, that humans could become an endangered species. “Of five possible criteria for what makes a species endangered,” Swan writes, “only one needs to be met; the current state of affairs for humans meets at least three.”
Between 1964 and 2018 the global fertility rate fell from 5.06 births per woman to 2.4. Now approximately half the world’s countries have fertility rates below 2.1, the population replacement level.