What are the REAL dangers of smoking weed?

I was thinkin about it and I want to here the real dangers of it...REAL dangers. No above the influence **** like "It's gonna ruin your life and you will most likely over dose and shoot your family in a pot fueled fury" and no complete stoner answers like "Nothin dude it makes women love you and you'll live forever". I want honest answers that have some valid proof behind them Im taking these answers very seriously.