That’s how science works bud. Correlation is really all we ever have for anything and you don’t leap from “no data” to “confident in causation” without miles and miles of “just correlative evidence of varying quality.”

And of course even once you get to high enough conviction to call it causation, it’s still liable to be overturned and to reveal itself as a mere correlation nonetheless!

Humans have never once “proved causation” of even a single phenomenon ever.

Not to mention how does one control the variables for lifespan and "green spaces".

This is a straight up pseudoscience and in its purest form.

It is practically intellectual fraud.

Not at all. That's not how science works. A huge percentage of rigorous scientific studies are specifically showing correlations between things.

"Correlation doesn't equal causation!" cried the internerds.

It doesn't need to. If you've got a set (P) of N people who consume substance X, and N people (Q) who did not consume substance X, and 100% of set P died within half an hour of that act, and 100% of Q are still happy little dandelions, that is an entirely valid scientific finding, and an entirely sufficient reason to stop the supply of substance X.