It is difficult to see how smoking tobacco harms your lungs and smoking pot does not.
I never claimed the latter didn't -- in fact I'd be astonished if there weren't similar damage due to the hot air and particulates, never mind the nicotine vs. THC arguments.
Lungs were not designed for breathing smoke, period. Anybody who's heard a smoker cough (tobacco or pot) should be able to see that.
There are numerous "degree of damage" arguments based on how much of what one smokes, but the baseline is, -any- foreign particulates, and -any- hot air, is not good for the lungs and potentially can create problems.
Please refrain from raising rational points on this thread...
Marijuana doesn't contain the poisonous compound nicotine...Does have as high a level of tar as cigs. but I don't think pot smokers smoke 20 cigarette sized joints a day.