Related Question on Metaculus:
From a recent Guardian piece,
The end of humankind? It may be coming sooner than we think, thanks to hormone-disrupting chemicals that are decimating fertility at an alarming rate around the globe. A new book called Countdown, by Shanna Swan, an environmental and reproductive epidemiologist at Icahn School of Medicine at Mount Sinai in New York, finds that sperm counts have dropped almost 60% since 1973. Following the trajectory we are on, Swan’s research suggests sperm counts could reach zero by 2045. Zero. Let that sink in. That would mean no babies. No reproduction. No more humans. Forgive me for asking: why isn’t the UN calling an emergency meeting on this right now?
The chemicals to blame for this crisis are found in everything from plastic containers and food wrapping, to waterproof clothes and fragrances in cleaning products, to soaps and shampoos, to electronics and carpeting. Some of them, called PFAS, are known as “forever chemicals”, because they don’t breakdown in the environment or the human body. They just accumulate and accumulate – doing more and more damage, minute by minute, hour by hour, day by day. Now, it seems, humanity is reaching a breaking point.
Swan’s book is staggering in its findings. “In some parts of the world, the average twentysomething woman today is less fertile than her grandmother was at 35,” Swan writes. In addition to that, Swan finds that, on average, a man today will have half of the sperm his grandfather had. “The current state of reproductive affairs can’t continue much longer without threatening human survival,” writes Swan, adding: “It’s a global existential crisis.” That’s not hyperbole. That’s just science.
As of 2021, the total fertility rate is 2.44 according to the UN, as reported by Our World in Data.