Plastics have alternatives beat

Plastics have alternatives beat
Charlotte Metcalf

Plastics have alternatives beat when it comes to lower total greenhouse gas contributions.

This is the headline finding of a report into the climate impact of plastics from McKinsey & Company, a global management consulting firm committed with more than 90 years’ experience as its clients’ most trusted external adviser.

According to the authors plastics are frequently maligned when it comes to leakage to the environment, toxicity, use of resources, production emissions, and ocean pollution but they also play an important role in enhancing use efficiencies and reducing greenhouse gas emissions.

“Multiple environmental factors should be considered in material selection,” they wrote. “This paper examines the total greenhouse gas (GHG) contribution of plastics versus its alternatives, including product life cycle (cradle to grave) and impact of use. Our objective is to contribute to the dialogue on material choice and broaden the available fact base for the evolving discussion around plastics.”

The analysis conducted by the team was based on 2020 information from the United States and excluded ocean pollution.

As part of its methodology, they looked closely at examples from five sectors with the highest consumption of plastics—packaging, building and construction, automotive, textiles, and consumer durables—representing around 90% of global plastics volume.

The three critical steps were:

  • Selecting application categories based on the top five sectors with the highest plastics consumption, and representative applications for which at-scale, viable choices between plastics and alternatives exist today, avoiding niche or new solutions.
  • Creating detailed greenhouse gas assessments for selected applications within each application category.
  • Assessing the total greenhouse gas contribution of applications throughout the product’s life cycle, including its value-chain impact.

There were two important overall findings. The first was that plastics have a lower greenhouse gas impact in 13 of the 14 non-plastic alternative applications analysed, including both direct and indirect value-chain emissions. The second was that, for the majority of food packaging applications, there are few viable alternatives to plastics.

To further illustrate how the analysis was carried out, what follows is the report’s in-depth review of soft drink containers:

“We began our deep dive with an application most people are familiar with: soft drink containers. The majority of soft drinks today are packaged in PET bottles, aluminium cans, or glass bottles. We based our analysis on 20-ounce PET bottles, 12-ounce aluminium cans, and 12-ounce glass bottles, which account for 17.0, 60.0, and 0.3 percent of the carbonated soft drink market in the United States, respectively. These specific sizes were selected because they represent the most common beverage container sizes for their respective material substrates.

“Comparing a 20-ounce PET bottle with a 12-ounce aluminium can favours the PET bottle because the material-to-volume ratio is significantly higher for smaller containers. In other words, it would require more plastic to distribute 100,000 fluid ounces of soda in 12-ounce PET bottles than in 20-ounce PET bottles, which would increase the GHG emissions. However, these sizes represent what consumers typically choose to purchase.

“PET bottles have the lowest emissions because of their lightweight properties and the low amount of energy required to produce them.18 By contrast, aluminium cans have two times the emissions of PET bottles, and emissions from glass bottles are three times higher. Although the PET bottle has the lowest production emissions, it has the least favourable GHG emissions for its end-of-life disposition.

“PET has the lowest recycling rate and credits from avoided virgin production among these three materials. It also has the highest emissions from WtE. (PET releases CO2 when burned, whereas aluminium and glass do not.) However, the GHG impact of production emissions is more significant than end-of-life disposition emissions, resulting in PET having the lowest GHG impact.

“The value-chain impact for soft drink containers is relatively small. The average shelf life is approximately 13 weeks for PET bottles versus 52 weeks for aluminium cans and glass bottles. PET bottles also have slightly higher spoilage rates (loss of carbonation) than aluminium and glass. That said, glass bottles break more easily than PET and aluminium. In both cases, additional GHG emissions are incurred from soft drink and bottle production to compensate for incremental spoilage and breakage of PET and glass bottles. However, in neither case is the total GHG contribution the result of incremental spoilage or breakage of materials.”

“As a result of the criticism against plastics, there are various alternatives being touted to consumers, manufacturers, retailers, hoteliers and restauranteurs, including biodegradable and compostable plastics, cardboard or paper bottles or cartons, cans, and glass recycling or refilling,” added South African National Bottled Water Association (SANBWA) CEO, Charlotte Metcalf.

“But the solution is not as simple as replacing plastic with one of these alternatives, no matter what the people who sell them say, as McKinsey’s report highlights.

WWF sustainable materials specialist Paula Chin maintains that replacing plastic with alternative packaging materials is not the answer to pollution and may even worsen various industries’ environmental impact. Instead, she believes a systems-based approach focusing on reuse and refill models must be implemented in which policymakers and businesses are held fully accountable.

“This is a way forward that SANBWA and its members fully buy into. In the South African context, the Government is implementing Extended Producer Responsibility (ERP) legislation with respect to packaging. And, within this, the adoption of ‘design for recycling’ and ‘a circular economy’ play a big role, and one that the whole value chain needs to be a part of.

“However, we can only do so if our population changes its behaviour when it comes to littering and recycling, and when we are fully aware of and educated about the issues the country’s recycling industry faces,” she added.

As a responsible corporate citizen, SANBWA is playing its part to discourage plastic waste: Its environmental stewardship protocols address measures to ensure source sustainability and protection, water usage minimisation, energy efficiency, solid waste minimisation, and support post-consumer recycling initiatives.

As an organisation, SANBWA was among the first worldwide to require its members to follow specific recycling guidelines. It also expects members to:

  • Register as producers of waste, join a recycling NGO and pay toward the recycling levy for every ton of packaging used
  • add the ‘please recycle’ sign on all labels.
  • Design for recycling by using recycling friendly materials or recycling optimal materials as stipulated in the SANBWA Bottled Water Standard

The McKinsey & Company report “Climate impact of plastics” was written by Stefan Helmcke, Thomas Hundertmark, Chris Musso, Wen Jie Ong, Jonas Oxgaard, and Jeremy Wallach. Also contributing to the paper were Mackenzie Donnelly, Wenting Gao, Eric Hannon, Conrado Kurtz, Jeni Sorli, Pieterjan Van Uytvanck, and Paige Xu for their contributions to this paper.