To conclude this series about bioplastics and the biodegradability (or lack thereof) of plastic products and packaging, I want to discuss the future of what I consider to be one of the only viable alternatives to plastics derived from non-renewable resources: durable bioplastics. The key word here is durable, because biodegradable plastics of any composition are not the long-term sustainable solution we need. When you compost a biodegradable plastic cup, that polymer can no longer be reused and maintained, meaning all of the energy and material inputs are lost in the soil.