University of Cambridge study finds non-plastic packaging may harm environment more

New research published this week in the journal *Environmental Science & Technology* finds that swapping polyethylene (PE) packaging for paper, glass, aluminum or steel often fails to lower a product’s overall environmental impact, and can sometimes make it worse. The study, conducted by a team at the University of Cambridge, compared the full life‑cycle emissions of each material across a range of common consumer goods, from bottled water to snack foods, and concluded that the assumed “green” switch to alternatives does not automatically translate into lower carbon footprints, water use or waste generation.

The work arrives at a time when governments and retailers are scrambling to curb plastic pollution. Europe’s recent single‑use plastics ban, the U.S. Plastic Waste Reduction Act, and a wave of corporate pledges to eliminate “single‑use” plastics have all pushed companies toward paper cartons, glass bottles and metal cans. Those moves are driven by public pressure and the belief that non‑plastic materials are inherently more sustainable. However, the Cambridge analysis shows that the production of paper requires large quantities of water and energy, glass is heavy and fuel‑intensive to transport, and aluminum and steel demand high‑temperature smelting that releases significant greenhouse gases. In some scenarios, the study found that a paper‑based snack wrapper generated up to 30 % more CO₂e than its PE counterpart, while a glass water bottle could emit 40 % more over its lifetime due to transport weight.

Lead author Dr. Elena García said the findings “highlight the danger of swapping one material for another without looking at the whole system.” The researchers used life‑cycle assessment data from the European Product Environmental Footprint database and modeled typical usage patterns, including recycling rates that vary widely by region. Their results suggest that only when high recycling rates are achieved and renewable energy powers manufacturing do alternatives begin to outperform PE. The paper also notes that reusable options, such as refillable glass bottles, can cut impacts dramatically if they are returned and cleaned efficiently.

The study is prompting calls for more nuanced packaging policies that go beyond material bans. Industry groups, including the Plastics Industry Association, have urged regulators to consider functional equivalence and end‑of‑life outcomes rather than focusing solely on material type. Environmental NGOs say the research supports a shift toward reducing overall packaging volume and improving recycling infrastructure. Policymakers in the EU are expected to review the findings as they draft the next iteration of the Packaging and Packaging Waste Directive, which may incorporate life‑cycle performance metrics to guide future material choices.