Can climate change increase and hamper international migration at the same time? Yes, according to a new study from Germany.
Can climate change increase and hamper international migration at the same time? Yes, according to a new study from Germany.
Unrelenting rain is keeping rivers and wetlands at record highs throughout the year, with devastating consequences.
The essay the Washington Post’s editorial board recently published downplaying the population disaster is itself a disaster — a misrepresentation of the implications of a global human population that recently reached 8 billion people.
To publish an editorial on the population crisis titled, in part, “That’s probably a good thing” gives people license to consume as much as they want, to have as many super-consuming children as they want and simply get on with their day-to-day activities. It offers no hope of finding our way out of the catastrophe, of avoiding the tightly population-related existential threats of climate disruption, biodiversity extermination, toxic chemicals (likely related to the global decline in human sperm count), declines in soil quality, ground water, and other resources and escalating chances for nuclear war.
For example, Earth Overshoot Day — the day when humans have used all of the biological resources that Earth regenerates during the entire year — occurred this year on July 28. The last time we lived within the productivity limits of our planet was about 50 years ago, when the global population, at approximately 3.8 billion, was less than half of what it just reached.
World-class economist Sir Partha Dasgupta, who in 2020 completed review of the economics of biodiversity for the U.K. Treasury Department, calculated that if everyone in the world were given an annual income of about $20,000, a human population of perhaps 3.2 billion people would be able to live sustainably on our planet. Earlier estimates were even lower. The huge disparities between current gross national income per capita at $70,480 in the U.S. and $3,993 in countries of Sub-Saharan Africa seem to make it virtually impossible for humanity to live sustainably on this planet under current economic distribution. When will Americans or western Europeans be ready to give up large parts of their current standards of living to even things out globally? And as for the eight individuals who control as much money as the 3.6 billion poorest among us, they certainly don’t have any urge to level matters out either.
The Washington Post editorial board apparently doesn’t realize that neither the planet nor people react to percentages but to numbers. While “only” about 25% of people are living in misery today, at the very least malnourished, that’s two billion people. And the other 75% are busily bringing down civilization.
The editorial contains many of the long-disproved population bromides from fear of the aged to more minds bringing new ideas. It is about as dangerously misleading as anything we’ve read anywhere on a topic that affects us all so profoundly.
The Washington Post was not alone in questionable coverage of the population data. The New York Times accepted a fine opinion piece on population by Peter Gleick, a world-renowned expert on water and climate issues, but withdrew it to publish a column by Somini Sengupta entitled “The Population Question.” Sengupta properly recognizes the major role of the rich in emitting greenhouse gasses and the critical importance of women’s education, but then acts as if climate disruption were the only existential threat. She writes “history is littered with population control horrors” but fails to name similar “growthmania” nightmares. There certainly have been such horrors, especially in forced eugenic sterilizations in the U.S. and those trying to deal with overpopulation in India. But Sengupta does not mention horrific acts of “growthmania” that dwarf those episodes, and that were usually guided by the very same colonial and racist thinking behind population control horrors. For example, there were many millions of lives destroyed in the name of population growth from the European invasion of the Americas, not to mention the triangular slave trade and Hitler’s immense slaughter of Jewish and Slavic peoples in search of eastern “Lebensraum” and “racial purity.”
Sadly, the third prominent article we want to discuss marking the “passing 8 billion” was published in the Guardian, usually one of the best major publications on critical environmental issues. We will not bore you with an analysis of the same long-dealt-with mistakes, except to note that the author discounts the obviously massive population contribution to overconsumption. He even makes the classic mistake of focusing on numbers without considering the real world.
More than 15,000 scientists have signed on to the renewed scientific warning on population-related issues.
“To prevent widespread misery and catastrophic biodiversity loss, humanity must practice a more environmentally sustainable alternative to business as usual,” the 2017 report reads. “Soon it will be too late to shift course away from our failing trajectory, and time is running out.”
As Earth passes 8 billion people, these words ring even more true. And we need more intentional, accurate reporting on the many impacts that this over-capacity creates.
Peter H. Raven is president emeritus, Missouri Botanical Garden, St. Louis.
Paul R. Ehrlich is a Bing Professor of Population Studies at Stanford University.
Dr. Shanna Swan, a leading reproductive epidemiologist at Mount Sinai and adjunct scientist with Environmental Health Sciences, discusses a new analysis that found that sperm count globally dropped by more than half between 1973 and 2018, and that the decline is accelerating.
Dr. Swan, a coauthor of the new analysis published in the Human Reproduction Updatejournal, outlines the implications of this infertility crisis and some of the environmental causes. Swan authored the book Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race.
Watch the video above for Dr. Swan's thoughts on the latest findings, and read about the report here.
For years, scientists across the world have gathered evidence showing declines in sperm quality. Now, new research compiling the results of those studies has found that sperm count has dropped dramatically around the world, and the rate of decline is accelerating.
In a new analysis, researchers at Mount Sinai Medical Center, the University of Copenhagen, and the Hebrew University of Jerusalem, among others, found that sperm count globally dropped by more than half between 1973 and 2018, and that the decline is accelerating: Since 1972, sperm count has dropped by about 1% each year. Since 2000, the annual decrease has been, on average, more than 2.6%.
The findings raise concerns that an increasing number of people will need assistance to reproduce, as well as concerns about the overall health of human society, since low sperm count is linked to higher rates of some diseases. And while scientists are still trying to tease out the reasons for the drop, chemical exposures, especially to pesticides, are a likely factor — and climate change may even play a role. Researchers are calling for urgent action to bolster more research into sperm count, determine the causes of the decline, and prevent further deterioration of male reproductive health.
“We have clear evidence that there is a crisis in male reproduction,” Hagai Levine, lead author on the study and an epidemiologist at the Hebrew University of Jerusalem, told EHN.
The study builds on the team’s previous research, which showed a decline in sperm count in North America, Europe, Australia, and parts of Asia of 28.5% between 1973 and 2011. Adding data from 38 studies to the new analysis has made the case for sperm decline stronger, Shanna Swan, an author on the paper and a leading reproductive epidemiologist at Mount Sinai, told EHN. “It’s really alarming,” said Swan, who is also an adjunct scientist with Environmental Health Sciences, which publishes EHN.org.
The research found that the average global sperm count in 2018 was 49 million per milliliter of semen. When a man’s sperm count drops below about 45 million per milliliter, his ability to cause a pregnancy starts dropping dramatically, said Swan. She said the results could mean that in the coming decades, large swaths of the global population of men could be subfertile or infertile, or could require assisted reproduction techniques, like in vitro fertilization (IVF), hormone treatment, or a technique called intracytoplasmic sperm injection (ICSI), in which sperm are directly injected into an egg.
In addition to the drop in average sperm count, Levine said it was surprising that the rate of decline was accelerating, rather than slowing down. “Is there a tipping point, that once you cross, you get an even worse situation?” he said. “That’s something to really pay attention to.”
Overall, said Levine, the results indicate that “something is very wrong with our global modern environment.”
Sperm count is not only a reproductive concern, but an indicator for other health problems in men, and is used as a predictor for male longevity. Men with poor sperm count tend to have higher rates of cardiovascular disease, certain cancers and even death, Michael Eisenberg, a professor of urology at Stanford University who was not involved in the research, told EHN. “This decline in sperm count could also suggest other health concerns,” he said.
A 2016 study authored by Eisenberg found that diabetes and other diseases were associated with lower reproductive health. However, said Eisenberg, the reason why overall health is linked to sperm quality is still unknown.
Eisenberg said the new study on sperm count decline is a “powerful addition” to previous evidence that sperm count across the globe has declined.
Though the reasons for the drop were not discussed in the paper, scientists have known for decades that certain environmental factors, like exposures to pesticides (such as atrazine, alachlor, and diazinon) and other endocrine-disrupting chemicals, like phthalates, and polychlorinated biphenyls (PCBs), can have impacts on reproductive health. Nearly 20 years ago, for example, Swan and other researchers published an analysis of research into links between pesticide exposure and sperm quality, and found that 79% of studies indicated a decrease in sperm quality among those exposed to the chemicals. Diet, activity level, and stress may also play a role.
Swan and Levine said exposures to chemicals in the environment and other factors likely all play a substantial role in the sperm count trend. And, the risk factors are related; for example, obesity is a risk factor for lower quality sperm, but certain endocrine-disrupting chemicals — which interfere with how hormones work — are thought to contribute to obesity, as well. Diet is hard to decouple from chemical exposures, too, since pesticide residues linger on much of the food we eat.
Additionally, both Swan and Levine said climate change could be a factor, both due to climate-related stress and actual fluctuations in temperature, since heat waves are linked to decreases in sperm quality.
Prenatal exposure may be a contributor, too. Chemical exposures during the male “programming window,” when reproductive traits are formed in utero, have an outsized effect on sperm quality later in life, said Swan. For example, she said, when a man smokes — a known endocrine-disrupting activity — he lowers his sperm count by about 20%. When a male is born to a woman who smokes, his sperm count is reduced by about 50%. Those effects may last for generations before subsequent children and grandchildren return to normal sperm counts.
Levine is optimistic that scientists and policymakers can reverse the trend if they can determine the causes. Swan pointed to the sharp drop in cigarette smoking in the past 50 years as evidence that widespread lifestyle changes are possible, and said that any large-scale adoption of healthier habits, like better diets and more physical activity, can help improve reproductive health.
Making individual lifestyle changes like choosing organic, pesticide-free produce and staying away from certain plastics and chemical products can help lower a person’s exposure to endocrine-disrupting chemicals, too. However, doing so can be difficult, especially for disadvantaged populations with less access to fresh foods, higher environmental exposures, and fewer means to purchase safer, non-toxic household goods.
To truly tackle the problem, though, much more research is needed, said Swan. One thing she’d like to see would be better tracking of sperm count, similar to how the U.S. Centers for Disease Control and Prevention tracks obesity. Levine also said better surveillance tools will be crucial to understanding the problem more deeply.
Once humankind “defines a problem and puts our resources and mind into it, we find solutions that we could not have thought about when we started,” said Levine. “It's always theoretically reversible.”