Oxford Academic - Temporal trends in sperm count: a systematic review and meta-regression analysis. Here is a link to the actual published study.
While this has been studied since the early 1970s, scientists still have no idea as to what is causing it, or so we are told. In fact, they have stated that smoking, obesity and even global warming may be causing it; but, those are lies. Lets start with smoking, it has been steadily decreasing in the west since the late 1960s, not increasing. However in the places where sperm counts are not going down, smoking has either remained relatively the same or increased, such as in Asia. Obesity also does not explain it. As for global warming, that is just laughable as global means global and the impact would be worldwide, not just in western countries.
So why doesn't the media care more about this issue? Why aren't western governments freaking out and spending the same amount of attention to this issue that they do to global warming. I mean, after all, at this rate the sperm count in western males will be zero in another 40 years. It's just math. Could this be due to hormones in our foods? Could it be due to chemicals in our environment (actually the west regulates chemicals in our environment much more than does China, India, Africa or South America where sperm counts are not declining)? I guess the only people that don't need to be worried about global warming are people living in the western world because we won't live to see it.
CBS News - 40 percent of U.S. bee colonies died in past year. In 2015 this report came out. Again, very large numbers and no overwhelming concern from the media. It is mentioned; but, not very often, certainly not as often as whether or not Trump likes one or two scoops of Ice Cream or whether or not transgenders should be in the military (all 250 of them). So what is killing the bees? The most likely candidate is pesticides.
It is bad enough that western societies have dropped their birth rate by refusing to have children, in the future they won't be able to. Oh, and just in case you think this is a "white male" thing, it is not, it is all westerners, blacks, whites and Arab, Asian, African immigrants who move to the western world. The drop is not genetic, it is environmental.