I'm sure that Watson is using worst case examples and maybe even exaggerating a bit...but his point on the permanance of plastic is well taken. The stuff is forever. It won't go away on it's own like other pollution...

There is such a thing as biodegradable plastic....made from plant material. However...it is more expensive, so manufacturers aren't using it much. And the permanent nature of plastic is what makes it so useful for many exterior items. I have a poly-vinyl (plastic) fence in front my house now because I got tired of replacing wooden ones that rotted and needed constant maintanance. So replacing all plastics with bio-degradable types isn't the way to go either. I would say using biodegradable plastics for disposable items make a whole lot of sense, though. Garbage bags, food containers, diapers, etc....