Climate Change isn’t Helping Matters

According to a New Report, the Global Decline in Sperm Concentration is Accelerating

Credit, Ars Technica

A new study suggests that the average sperm concentration dropped by 51.6 percent between 1973 and 2018, with the total sperm counts dipping by 62.3 percent during the period.

In 2017, another study suggested that sperm counts among men fell between 1973 and 2011, with the concentration of sperm in the ejaculate of men in Western countries having plummeted by an average of 1.4 percent a year, resulting to an overall fall of just over 52 percent.

While the drivers behind the decline of sperm counts remain unclear, a report this week stated that nations will likely burn through their remaining carbon targets in less than a decade if they did not appreciably curtail their greenhouse gas emissions, a situation likely to propel the world past a critical temperature increase threshold, triggering a calamitous climate impact.

Of course, the latter report refrains from linking the critical temperature increase to the decline in sperm counts, only stating the repercussions of not keeping global temperature rise at 1.5 degrees Celsius and calling on humanity to release no more than 280 billion tons of carbon dioxide equivalents over the coming decades. Still, links exist between the declining sperm counts and the climate change-induced temperature increases.

Through a study published in the journal Demography, researchers reported that more births occurred in August and September in the United States, nine months after the coldest part of the year, suggesting that warmer temperatures relate to lower sperm productions.

In another study, comparisons among 131 men without azoospermia who contributed specimens in both summer and winter showed a decline during summer in sperm concentration, total sperm count per ejaculate, and the concentration of motile sperms. Thirty-two percent accounted for the mean decreases after an adjustment for possible confounding characteristics.

In yet another study, the exposure of male rats to an air temperature of 32 degrees Centigrade brought about fertility declines of around 75 percent, while thermal stress affected male reproduction, as the red flour beetle exposed to a single heat wave reacted with an appreciable reduction in their efforts to reproduce themselves, cutting more than 50 percent of their ability through a 42 degrees Centigrade compared to 30 or 35 degrees Centigrade controls.

In other words, if males exposed to single heat waves react with significant reduction in their efforts to have offspring, increases in the ambient thermal environment have a capacity to disrupt male reproduction functions, so it’s no surprise that reports after reports in recent years show declines in sperm counts on a worldwide basis.

Already, the repercussions of declining sperm counts during periods of climate change manifest. In 1991, the World Health Organization (WHO) estimated that infertility affected 20-35 million couples in Africa, with the male infertility factor accounting for 40-50 percent of the problem. Another study indicated that the sperm concentration among Asian men followed a mild declining trend over the period of 50 years, while some reports say the rate of reduction proved very significant in India, China, and Japan.

The global sperm bank market was valued at three billion dollars in 2021, but with the challenge of rising male infertility, it is projected to reach four billion dollars in 2030, expanding at a compound annual growth rate (CAGR) of 5.45 percent during the forecast period 2022-2030. According to a study, the condition could exacerbate by 2050, because while worldwide over 9 million infants have been born following ART procedures since 1978, the numbers could rise in 28 years' time, as a large proportion of people around the world would be unable to conceive without technological assistance. To illustrate the point about male infertility further, a report warned that following the current projections, sperm counts could settle at zero in 2045, meaning in the long term humans could become extinct if sperm counts in men continue to fall at current rates. A 2017 review went as far as to say extinction faces mankind if the trend of 50 to 60 percent drop in sperm counts recorded across Europe, North America, and Australia continues.

Unfortunately, climate change-induced temperature increases continue to be the trend across Europe, North America, and other places. And it could get worse in the future, because if emissions continue to increase rapidly as they have since 2000, global temperatures would be at least 2.4 degrees Fahrenheit warmer than the first half of the 20th century, and possibly up to 5.9 degrees warmer.

With a climate change-induced temperature making the world 5.9 Fahrenheit warmer if emissions continue at the present rate, male’s sperm counts could be affected, particularly with the link established by some between global warming and male infertility. Perhaps this could inspire humanity to double down on fighting climate change before an irreparable damage happens to the species.

Further Reading

Credit, News Medical

Climate change damages male fertility. Read More.

Research shows a significant sperm count decline globally. Read More.

Male fertility ‘precariously close’ to climate change extinction limits. Read More.

How climate change causes infertility. Read More.

What to Eat

Male smoothie, Credit, Tomakeamommy.com