This aerial view shows unpaved roads dividing a soy monoculture from the native cerrado in northeastern Brazil. The most biologically diverse savanna in the world, the cerrado has already lost roughly half of its original vegetation.
Biobased materials range from basic building materials that have been used for generations and require little processing—such as wood and straw—all the way to highly complex, processed plastics that owe as much to the chemistry lab as they do to a field of corn.
The green building industry has tended to lump anything with a biological component into a “biobased” category and pat itself on the back for moving away from fossil fuels. Simply switching from the typical nonrenewable feedstock to a renewable one has immediate environmental benefits for some materials, but for others the impact of the material’s biological source on the product is dwarfed by impacts from manufacturing or other stages of the product’s life. In many cases, biobased material sourcing comes with its own environmental problems—big ones. For example, growing corn carries huge environmental burdens, from soil erosion and nutrient runoff to the use of pesticides, water, and energy. Using corn as a feedstock for plastics, as we’ll explore below, trades one set of impacts (deriving feedstocks from fossil fuels) for another.