Plastics and sustainability: Circularity and going green are needed

Our ever-increasing use of plastics is raising growing environmental concerns, particularly regarding their fossil resource use and greenhouse gas emissions. In his PhD thesis, Copernicus' Paul Stegmann shows that we need to drastically improve our recycling efforts and switch from fossil to biogenic resources if plastics are to fit in a sustainable future.

A key chapter in Stegmann’s thesis focuses on a dynamic long-term model of the global plastics sector, which assesses the impacts of strategies to improve recycling and circularity, substitute fossil resources with biomass, or a combination of the two. “We see that strategies based only on circular economy or biomass solve parts of the problem but not all of it," says Stegmann. "Using only biomass without recycling still requires a lot of primary material, while only focussing on recycling still uses fossil resources and does not fixate biogenic carbon in materials. Combining biomass use and recycling reaps the potentials of both and could turn the plastic sector into a net carbon sink while also reducing its resource consumption.”

The relevance of recycling and biomass use, a ‘circular bioeconomy strategy’ was also confirmed in a case study on plastic bottles. Substituting fossil material with a biobased equivalent and enhancing its chemical or mechanical recycling shows the best performance in terms of avoiding greenhouse gas emissions and primary resource use.

Stegmann will defend his thesis titled ‘Growing in circles, A circular bioeconomy for plastics’ on 25th November 2023.