Review literature

Concerns over climate change and the security of industrial feedstock supplies have been opening a growing market for biobased materials. This development, however, also presents a challenge to scientists, policy makers, and industry because the production of biobased materials requires land and is typically associated with adverse environmental effects. This article addresses the environmental impacts of biobased materials in a meta-analysis of 44 life cycle assessment (LCA) studies. The reviewed literature suggests that one metric ton (t) of biobased materials saves, relative to conventional materials, 55 ± 34 gigajoules of primary energy and 3 ± 1 t carbon dioxide equivalents of greenhouse gases. However, biobased materials may increase eutrophication by 5 ± 7 kilograms (kg) phosphate equivalents/t and stratospheric ozone depletion by 1.9 ± 1.8 kg nitrous oxide equivalents/t. Our findings are inconclusive with regard to acidification (savings of 2 ± 20 kg sulfur dioxide equivalents/t) and photochemical ozone formation (savings of 0.3 ± 2.4 kg ethene equivalents/t). The variability in the results of life cycle assessment studies highlights the difficulties in drawing general conclusions. Still, common to most biobased materials are impacts caused by the application of fertilizers and pesticides during industrial biomass cultivation. Additional land use impacts, such as the potential loss of biodiversity, soil carbon depletion, soil erosion, deforestation, as well as greenhouse gas emissions from indirect land use change are not quantified in this review. Clearly these impacts should be considered when evaluating the environmental performance of biobased materials.