Greener does not always mean lower emissions

The shift towards more sustainable packaging is accelerating, but choosing a material perceived as greener does not necessarily result in a lower carbon footprint. Packaging decisions involve complex trade-offs between material production, weight, transportation, product protection, recycling and end-of-life management.

As brands face growing pressure to reduce plastic use and adopt more sustainable alternatives, understanding these trade-offs is becoming increasingly important. A packaging material can perform better in one environmental category while generating higher greenhouse gas emissions elsewhere in its life cycle.

Material choice can change the carbon balance

Glass is a clear example of this challenge. Although it is widely recyclable and can be repeatedly recycled without losing its fundamental properties, glass packaging is significantly heavier than many plastic alternatives. The additional weight can increase emissions during transportation and distribution.

Plastic, meanwhile, benefits from its low density and relatively high strength-to-weight ratio. Using less material can reduce packaging weight and transport emissions, although the environmental advantages can be offset by fossil resource use, production emissions and inadequate waste management.

The European Commission has previously highlighted the role of lightweight packaging in reducing transport-related greenhouse gas emissions, while also stressing the importance of limiting packaging weight and volume to what is necessary for its function.

Life cycle assessment provides a broader picture

These trade-offs are why life cycle assessment (LCA) is increasingly important when evaluating packaging alternatives. Rather than focusing on a single characteristic such as recycled content, recyclability or biodegradability, LCA considers environmental impacts across different stages of a product's life.

This can include raw material extraction, material production, packaging conversion, transportation, use and end-of-life treatment. The result can challenge assumptions about which material is inherently more sustainable.

For example, replacing conventional plastic with a heavier material may reduce dependence on fossil resources but increase transport emissions. Similarly, switching to a bio-based or compostable material may reduce certain environmental impacts while creating additional agricultural, processing or waste-management requirements.

Packaging also protects the product

The environmental impact of packaging cannot be considered independently from the product it protects. Packaging that is slightly more resource-intensive may still produce a lower overall environmental impact if it significantly reduces food or product waste.

This is particularly relevant for food packaging, where maintaining shelf life, preventing damage and controlling moisture or oxygen exposure can be more environmentally significant than the packaging material itself.

Arla, for example, notes that packaging represents less than 5% of its overall carbon footprint and emphasises that packaging must balance material efficiency, recyclability, food safety and product protection.

Recycling and end-of-life can change the result

The final stage of the packaging life cycle is another major variable. A material may be technically recyclable but still achieve limited environmental benefits if collection, sorting and recycling infrastructure are unavailable or inefficient.

Bio-based and compostable materials illustrate this challenge. Research has found that compostable plastics can offer advantages in specific applications, but their environmental performance depends heavily on production methods and the waste-management infrastructure available at the end of their useful life.

Consequently, packaging designers increasingly need to consider the conditions in which packaging will actually be collected and processed rather than relying solely on its theoretical recyclability.

Avoiding sustainability decisions based on a single metric

The growing complexity of packaging sustainability means that companies cannot rely on a single environmental indicator when selecting materials. Carbon emissions are important, but so are resource consumption, water use, waste generation, recyclability and the ability of packaging to protect the product.

A packaging solution with a lower carbon footprint may perform poorly in another environmental category, while a highly recyclable material may have a relatively high production footprint. The most appropriate solution therefore depends on the specific product, supply chain and waste-management system.

Data-driven packaging design is becoming essential

As sustainability claims face greater scrutiny from consumers and regulators, companies will increasingly need reliable environmental data to justify packaging choices. LCA can help identify where the largest impacts occur and determine whether a material substitution actually delivers an overall improvement.

The objective should therefore not simply be to replace one material with another marketed as “greener”. Instead, packaging design needs to consider the entire system, from raw material production to end-of-life, while maintaining the essential function of protecting the product.

For the packaging industry, this means that the future of sustainable packaging will depend less on choosing a universally “green” material and more on designing solutions based on measurable environmental performance. In many cases, the most sustainable package may not be the one that appears the most environmentally friendly at first glance.