Can smoking weed give you emphysema?

We don't know: No long term studies have been done to determine if smoking weed causes emphysema. While there are differences between weed and tobacco, i would not be surprised if the answer is yes.

Probably yes: There haven't been the kinds of studies done for marijuana smokers as there have for cigarette smokers. A recent study showed that marijuana was somewhat less likely to cause lung damage than tobacco. Nonetheless, the smoke contains hot particulate debris, tar, carbon monoxide, and, if you roll them, paper ash. If you smoke enough, you can bet there will be lung damage. (have you tried tea?).

Unlikely: Chronic bronchitis has been described in habitual cannabis smokers, but since the volume of smoke daily is usually much smaller than that of cigarette smokers, emphysema is unlikely.