This is an interesting theory, you would need to find birthrates matching the industrial pollution rate, which my guess is it doesn’t totally. I’m sure it’s a measure of multiple factors where a big one is teenagers are having less sex and first sexual encounter is later. https://opa.hhs.gov/adolescent-health/adolescent-sexual-and-reproductive-health/data-and-statistics-on-adolescent-sexual-and-reproductive-health (Look at figure 1)

Maybe people are understandably uncomfortable with self immolation? Nobody has ever liked an effective activist in their time. The civil rights protesters in USA had a <25% approval rate in the 60s.

I think this person did what he thought was right, and I will remember him for that. And peace can’t come soon enough.