I have spoken to several green-minded people over the past few years and am encouraged to hear their passion for the environment. Many have espoused the view that we could solve much of the world’s plastic pollution by using plant-derived plastics. They go on to explain that the world is changing and that more and more people are thinking about sustainability. More are willing to make an effort to save our planet. They feel the demand for biodegradable, plant-derived plastics can grow and that, eventually, all new products can be manufactured from this source.
Inevitably, the conversation then takes an abrupt turn as I begin to explain that plant-derived plastics sound wonderful on the surface, but are not in fact the answer. I point out that all plastics are created equal. For example, the polyethylene (PE) used to make a plastic bag is essentially chemically and physically identical whether it be derived from oil or from a plant. The same holds true for polyethylene terephthalate (PET) used to make water or pop bottles. Plastic made from either oil or plants will last in the environment for thousands of years. The source of the plastic is irrelevant.
Once I reveal this fact, the conversation often shifts to the idea that we should not use polyethylene or polyethylene terephthalate, but instead should make products from proven, biodegradable material. Unfortunately, that too has many issues. If a material would readily biodegrade, it would not be suitable for preserving food, so that would be difficult. Further, something characterized as biodegradable will not break down in the light-free, oxygen-deprived environment of a landfill or in a normal household compost pile. In fact, under some conditions, so-called biodegradable plastics can combine with other landfill materials to form more toxic substances. Many of these “biodegradable” plastics will only break down in high-temperature, industrial-scale composters.
Typically, I then convey my biggest concern. People who believe that "biodegradable” plastic will break down in nature are more likely to discard plastic carelessly, believing that there is no environmental consequence. Nothing could be further from the truth. “Biodegradable” plastics do not degrade if they end up in a stream, river, lake or ocean and they contribute to marine litter which is killing wildlife and endangering our health.
The conversation then usually segues to how bad an idea it is to use oil even if we must recycle the plastic regardless of it being derived from plants or from oil. Some people argue that the answer lies in growing more industrial-grade corn for the production of ethanol for making plastic. They assert that this corn is not grown for human consumption and does not compete with food sources. While this argument seems reasonable at first glance, it fails to consider that it takes land, fertilizer and fuel for farm equipment to plant, harvest, and subsequently transport harvested corn. This creates a significant carbon footprint. This land and the same equipment and resources could be used to grow food.
My closing point in these discussions is that plastic is an amazing material that can last for thousands of years and that there is a better solution than simply eliminating its use or destroying it. The answer is to reuse it over and over again, using low-energy ways to transform today’s plastic waste into tomorrow’s useful products.
Plastic is an amazing resource. We need to start collecting our “plastic garbage” and transforming it into products people need which will raise the standard of living for everyone everywhere. The reuse of plastic can spawn a new industry and create meaningful employment to the benefit of all.