Whether or not marijuana bags are environmentally friendly depends largely on the material they are made of.
Generally speaking, paper marijuana bags are more environmentally friendly because they are biodegradable or recyclable; plastic marijuana bags are less environmentally friendly because they are difficult to biodegrade or recycle; and aluminum foil marijuana bags fall somewhere in between because they are recyclable but difficult to biodegrade.
If you are environmentally conscious, consider using biodegradable or recyclable materials or choosing the right size and quantity to reduce waste and pollution.