We’ve the claim today that climate change will damage male fertility because sperm are heat sensitive. The short answer to this is no. The longer is no, don’t be so damn stupid. We humans are mammals, meaning that we self-regulate our body temperature. That’s not going to change as the outside air temperature goes up a degree or two. As it also isn’t true when we move north or south a coupl’a hundred miles. You have noted that humans do indeed live and reproduce in different latitudes? Good, there’s the proof then.
This is simply silly therefore:
The latest problem to be linked to global warming: male sperm counts.
It’s not good news. According to a new study published Tuesday, male fertility appears to decline as temperatures soar. The study showed “clear evidence” that stress from heat waves reduces “sperm number and viability” in bugs.
Yes, the scientists used beetles to test their theory. But researchers say the insects can be used as a proxy for people.
Sure, there are some things we can use beetles as proxies for. But body temperature regulation not being one of them, we being those mammal things, they not:
Heatwaves can damage the sperm of insects and make them almost sterile, according to new research.
Scientists exposed beetles to experimental heatwaves in the laboratory, which resulted in reduced male fertility.
The effects could be passed down to the beetles’ offspring.
Further work could shed light on whether climate change is a factor behind mass declines in insect populations, say researchers.
All of that seems entirely fair. Whether it’s true or not I’ve no idea but I’ve no problem in believing it. It’s that this applies to humans which is nonsense. The biology in play here is simply entirely different.
Yes, human male sperm is sensitive to heat. That’s why the testes are outside the body, they working better with a little bit of air cooling. They prefer perhaps 1 oC below normal body temperature. But human body temperature does not vary with the outside air temperature. Or if it does then we boil or freeze to death. We’re mammals, the major use of food calories is that self regulation of temperature.
That is, unless we’re thinking that the outside air temperature is going to be regularly above 36 oC then climate change isn’t going to make any difference at all to human sperm.
The mistake here has been to apply a beetle finding to people. Sorry, biology just doesn’t work that way, not about body temperatures at least. But then, you know, anything to scare the proles into supporting the death of modern civilisation, eh?