What about biodegradable plastic bags?
Biodegradable plastic is a mixed bag (pun intended) as well; while biopolymers like polyhydroxyalkanoate (PHA) and Polylactide (PLA) are completely biodegradable in compost (and very, very, very slowly -- if at all -- in a landfill) and are not made from petroleum products, they are often derived from our food sources.
The primary feedstock for bioplastics today is corn, which is rife with agro-political conflict and often grown and harvested unsustainably; because of these reasons, and because it competes with food supply, it is not likely to be a long-term solution in the plastics world.
Plus, some bags marked "biodegradable" are not actually so -- they're recycled plastic mixed with cornstarch. The cornstarch biodegrades and the plastic breaks down into tiny little pieces but does not actually "biodegrade," leaving a yucky polymer mess (if in small pieces). The only way to avoid this? Look for 100% plant-based polymers, like the two mentioned above.
So, while it's good to have the alternative (and to recognize the innovation it represents), bioplastics aren't quite ready to save us from the paper or plastic debate.
Read more to get inside the numbers on the paper or plastic debate.