Here's a potential existential risk. Suppose a chemical is used for some task or made as a byproduct of another task, especially one that is spread throughout the atmosphere. Additionally, suppose it causes sterility, but it takes a very long time to cause sterility. Perhaps such a chemical could attain widespread use before its deleterious effects are discovered, and by then, it would have already sterilized everyone, potentially causes an existential catastrophe. I know this scenario for causing an existential catastrophe seems very small compared to other risks, but is it worthy of consideration?
There is a very short window for this to be a serious existential threat, on the order of a few decades. If mass sterilization does not happen soon, our technological ability to make babies using cloning and other technologies will outpace the need for genital-based reproduction.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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