Easily one of the best ideas I've ever seen proposed on this site. There is a Medical/Health, so maybe it could be a sub of that?

This is actually a productive and beneficial suggestion like you said, unlike most on here.

Not saying smoking trees is very unhealthy, but it can and does lead to unhealthy practices in a lot of people...not eating right, being lazy, unactive...basically proving some stereotypes to be true. Not putting this up wouldn't be the end of the world for me personally, but I think it can be a good thing.