The United States is viewed by many as a “magical” land of opportunity, where personal goals, dreams, and aspirations, are attainable through hard work and determination. One such objective is the opportunity to become parents. Here, many consider children as blessings, hopeful promises of a future generation—the continuation of mankind. Unfortunately for some, the traditional method of having a child is an inconceivable notion. They may never experience this natural biological process without the support of medical intervention, due to physical or genetic deficiencies. The United States Center for Disease Control (CDC) defines infertility as: “not being able to get pregnant after 1 year of unprotected sex.” Their statistical data states that “7% of married women aged 15 to 44…are unable to get pregnant after 1 year of trying,” and “about 12%…have difficulty getting pregnant or carrying a pregnancy to term”. To make things worse, scientific global studies are now supporting the argument that climate change is a contributing factor to anthropological biological infertility in the U.S. and worldwide. This is important, because innumerable articles have been written about climate change affecting fertility based on an individual’s personal choice, centered on societal and economical beliefs. In the July 5th 2018 UCLA article Climate Change is Making it Hard for Couples to Conceive, author David Clogan discusses a study he published in the journal Demography, stating “high temperatures have a significant negative effect on fertility and birth rates, and the research projects that as climate change drives temperatures up and increases the number and severity of heat waves, getting pregnant may become harder than ever.” In addition, research by UCLA environmental economist Alan Barreca, explores climate change’s impact on human infertility, concluding that “hot weather reduces chances of getting pregnant— and the problem is expected to get worse because of global warming.” This article will briefly discuss how climate change affects infertility in men and women living in the United States; and realistically, what, if anything, can be done to remedy its effects?
Weather and heat plays an important role in the desire for sexual intimacy, live birthrates, and functioning of male and female reproductive systems. Evolving scientific research indicates that climate change diametrically affects infertility in men and women, due to unconventional yearly seasonal meteorological conditions, caused by global warming or increasingly hot temperatures. “Global warming might directly affect fertility in two key ways. First, hot weather could affect sexual behavior. After all, physically demanding activities are more difficult at high temperatures. Second, temperature could negatively influence reproductive health factors such as sperm motility and menstruation.” A PMC article in the U.S. National Library of Medicine, Heat stress on reproductive function and fertility in mammals, states that heat “also adversely affects the reproductive performance of both sexes. In males, it reduces spermatogenic activity, while in females it adversely impacts oogenesis, oocyte maturation, fertilization development and implantation rate.” Research using insects and mammals indicate that heat affects healthy sperm production in males, but not females. Heatwave conditions “(9 to 13 degrees above the typical high temperature for 5 days) damaged male, but not female, reproduction. Heat waves reduce male fertility and sperm competitiveness, and successive heat waves almost sterilize males…” Author Kirs Sales of the university of East Anglia in eastern England states that “heat shock can damage male reproduction in warm-blooded animals…past work has shown that this leads to infertility in mammals,” To test this theory, the University of Lincoln (in the U.K) evolutionary ecologist Dr. Graziella Iossa, and behavioral ecologist Dr. Paul Eady, examined how heat affects male and female sexual organs using meal moths. The results were published in the Journal of Evolutionary Biology, and Trends. “The moths were exposed to different temperatures (ranging from 20–33°C) during their development and up to the point when, as adults, they were ready to mate. The study found that sperm got shorter (and were therefore less effective) the higher the temperature the moths were exposed to, and that both males and females were less likely to engage in copulation when reared at the highest and lowest temperatures. Where they did copulate, the duration also decreased with increasing developmental temperature.” Science Daily also published this 11/13/18 finding in their latest research news section, stating “heatwaves halved the amount of offspring males could produce, and a second heatwave almost sterilized males.” The testes are strategically located outside of the body so that sperm will not be destroyed by intense heat, thus, producing a low sperm count. According to the University of Rochester Medical Center in New York, in “human males, the testicles make sperm and, to do this, the temperature of the testicles needs to be cooler than the inside of the body…”.
In females, heat affects estrogen production, ovulation, desire for sexually intimacy, and the success of live birth. An indirect research using Florida cows demonstrated that “Heat stress has two major actions on physiology of the female that reduce the probability of a cow becoming pregnant. First, heat stress reduces ability to detect estrus. On one dairy in Florida, only about 18-24% of estruses in hot months were detected by herdsmen while 45-56% of estrus periods were detected in cool months… Secondly, heat stress causes a large reduction in fertility. In lactating dairy cows, pregnancy rates per insemination in the summer can be as low as 10-20% (Hansen and Aréchiga, 1999). Fertility is reduced because heat stress can damage both the oocyte and early embryo (Hansen, 2013). The oocyte can be compromised by heat stress as early as 105 days before ovulation (Torres-Júnior et al., 2008) and as late as the peri-ovulatory period (Putney et al., 1989b). The early embryo is also initially sensitive to heat stress but quickly becomes resistant so that heat stress on day 1 after estrus reduced embryonic development whereas heat stress at day 3 had no effect (Ealy et al., 1993).” In addition, “Heat stress affects many reproductive functions including endocrine activities in females… Heat stress also changes the luteal phase and ovulation in humans”. Furthermore, climate change due to global warm is also affecting a topic in IVF treatments. On 07/25/14, Healthcare-in-Europe.com posted the article Stop free fertility treatment for “lifestyle” babies to curb climate change, in its section on sterilization reversal. Professor Cristina Richie of Boston College, Massachusetts writes that “Assisted reproductive technologies are typically given in places with enormously large carbon footprints… The US…is the world’s second largest carbon emitter, producing 20 metric tonnes of carbon dioxide (CO2) per person per year, which multiplies by a factor of 5, with the birth of a child…Our carbon emissions don’t stay locked in one country, but spread out across the world…” She further states in BioEdge: Booethics from Around the World, that ““It is therefore the obligation of environmental policymakers, the ethical and medical communities, and even society to carefully weigh the interests of our shared planet with a business that intentionally creates more humans when we must reduce our carbon impact.”
Most in society are now understanding how climate change is responsible for environmental changes in the Earth’s ecosystem, regarding weather, atmosphere, and natural disasters. However, many never connect it to human infertility. Studies from the latter part of the 20th century is supporting this theory. “While much attention has been paid to overpopulation worldwide, declining birth rates and underpopulation are looming threats in the United States, Western Europe and Japan…According to a report by the Centers for Disease Control and Prevention, there were fewer births in the U.S. in 2017 than in any year since 1978.” Many now realize that climate change also affects reproduction, due to the intense temperatures and dramatic changes in seasonal weather patterns.
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