Plastic pollution is a global problem with growing negative effects. Reducing the manufacturing and superfluous uses of these polymers, in addition to increasing the selective collection and recycling of their waste, are also shared objectives on a global scale. Despite all this, putting truly effective solutions into practice is not easy and their implementation must take many elements into account.
A team led by experts from the University of Sheffield (United Kingdom) has carried out a study in which it becomes clear, in this sense, that the substitution of plastics for other materials (metals, glass, fiberglass, wood, paper, cardboard, cotton...) can in many cases cause an increase in greenhouse gas (GHG) emissions. That is, if things are not done well, the substitution of plastics can have negative effects on the climate.
The study has focused on calculating the emissions associated with plastic products compared to their alternatives, analyzing plastics and their substitutes in various applications, including packaging, construction, automotive, textiles and consumer durables. The research has been led by Professor Fanran Meng, from Sheffield's Department of Chemical and Biological Engineering, in collaboration with researchers from the University of Cambridge and the KTH Royal Institute of Technology. The results of this work have been published in the journal Environmental Science
The authors state that "in 15 of the 16 applications examined, plastic products actually generate lower GHG emissions compared to their alternatives," according to a summary of results released by the University of Sheffield. The calculations obtained indicate that, analyzing the life cycle of the treated products, the increase in emissions in alternative materials to plastic ranges from 10% to 90%.
To understand environmental impacts, British academics used a tool called life cycle assessment (LCA). This method helps compare how different products affect the environment. The study adopted an LCA approach to assess GHG emissions associated with plastic products versus alternatives in different sectors.
Even when focusing solely on direct life cycle emissions, plastics maintain their advantage in nine out of 14 applications. Factors such as the lower energy intensity during production and the weight efficiency of plastics contribute to reducing their environmental footprint compared to alternatives such as glass or metal.
Plastics also demonstrate superiority in upstream processes, including production and transportation, in 10 of 16 applications. This advantage is due to its lower energy intensity and lower weight, which highlights the efficiency of plastic materials in mitigating emissions, according to the study.
Fanran Meng points out that "not all alternative or recycled products are better for the environment than the products they replace." "Environmental policymaking needs a life cycle assessment to guide decision-making to ensure that GHG emissions do not increase unintentionally due precisely to the shift to alternative materials."
"Demand reduction, efficiency optimization, life extension and reuse/recycling are win-win strategies to effectively reduce emissions. Focusing solely on switching to alternative materials is not," they say. the authors.
The study has also revealed the complexity of the indirect impacts of the systems surrounding plastics, which play a substantial role in certain applications. For example, in scenarios such as insulation and hybrid vehicle fuel tanks, indirect impacts eclipse direct emissions from plastics, presenting a nuanced perspective on their environmental performance.
Additionally, plastic packaging plays a crucial role in preserving food quality across a wide range of categories, helping to prevent spoilage and the GHG emissions it causes. This essential feature highlights the immeasurable environmental benefits of plastic packaging compared to alternative materials.
Research findings suggest that optimizing plastic use, extending product life, increasing recycling rates and improving waste collection systems may offer more effective strategies to reduce emissions associated with plastic products.
"We need to consider all of these impacts when choosing which materials to use in products to ensure we are using the right materials for the right purpose and help us develop a sustainable plastics sector," highlights the lead author of the new study.
