(Credit: Remade)By the time plastic products reach their end of life, the bulk of their climate damage has already occurred, according to a study that reaffirms greenhouse gasses tied to plastics are mostly generated in prime resin production, shipping and molding. The study, funded by the Remade Institute, was recently published in the journal ACS Sustainable Chemistry & Engineering.
As the wider societal conversation about plastics continues to evolve, the material’s climate impact has been much-discussed, both in terms of harmful environmental impacts from production but also in regards to the energy and emissions benefits that can come from plastic use. The Remade-funded study focused on PET, HDPE, LDPE/LLDPE and PP in the US. It found that the full life cycles of those polymers accounted for about 100.6 million metric tons of carbon dioxide-equivalent emissions per year, which amounts to 1.5% of total US greenhouse gas (GHG) emissions.
Of that 100.6 million metric tons of CO2-equivalent emissions, 58.0% came from virgin resin production, 29.3% came from semi-manufacturing processes (essentially extruding and molding the resin), 7.7% came from end-of-life management, and 5.0% came from transportation within the US.
According to the research of PET and polyolefin material generated in the end-of-life stream, 77% was landfilled, 16% was incinerated and 7% was recycled. However, when assessing how much each of those end-of-life pathways contributed to plastics’ total emissions impact, incineration proved to have the heaviest hand.
Waste-to-energy plants produce electricity, theoretically offsetting the need for more carbon-intensive power plants. But the study found that waste-to-energy contributed the most to GHG emissions even taking into account the electricity generated, likely because waste-to-energy plants have a low electrical conversion efficiency rate. In addition, the study touched upon whether boosting recycling is the sole solution to reducing environmental impacts of plastics, or whether restricting virgin plastic production should be part of the equation.
Democrats in Congress recently introduced a bill that would put a halt to plastic manufacturing plant construction, pointing to a variety of health and environmental impacts in plastic production. But the legislation drew an outcry from plastics industry stakeholders, who don’t want to see any limits on the production and sale of plastics and argue that the plastics bring GHG benefits that substitute materials don’t.
For its part, the Remade report argues that ensuring a more sustainable supply chain and beneficial economic and social outcomes means relying on a number of factors, including but not exclusive to recycling.
