Highlights:

• Glass has the highest carbon footprint across all sizes and categories assessed, with values five to 12 times higher than cartons

• Aluminium cans with zero recycled content are comparable to glass

• Cans made with 70% recycled aluminium have approximately double the carbon footprint of cartons

• Plastic bottles made with no recycled content have a considerably higher carbon footprint than cartons and roughly double the footprint of recycled plastic

• Lightweight plastic bottles and bottles made with 100% recycled plastic have similar carbon footprint to cartons

Read on for more in-depth information. 

Have you ever thought about what type of packaging is better for the environment between a carton, aluminium can and glass or plastic bottle? Your first reaction may be to consider what will happen to the container at its end of life; will it be recycled or sent to landfill? 

But there are actually many other factors to consider when determining the environmental impact of a piece of packaging. This can include the extraction of raw materials, whether recycled content has been used, how much and what type of energy has been used in its production, water use, transportation, and even the weight of the product.

Taking all of these things into consideration, a new market-first comparative study, conducted on behalf of Tetra Pak in Australia and New Zealand and independently peer-reviewed, suggests out of the packaging assessed cartons are the consumer packaging solution with the lowest carbon footprint for beverages and food. 

The Life Cycle Assessment (LCA) – a respected technique used to assess the environmental impacts associated with all the stages of the life cycle of a product, process or service – compared the environmental performance of beverage and food cartons to other packaging choices available on the Australian and New Zealand markets in 2019/20. The study included packaging ranging from 200ml to 2L in various categories: long-life milk, fresh milk, juice, water and food.

The results

On average, cartons were found to have the lowest – or equal lowest – carbon footprint of all packaging included in the study across all sizes and product categories considered. This is due to a combination of their light weight, the relatively low impact of paperboard per kilogram, and the biogenic carbon (emissions from natural sources) sequestered and stored in the paperboard during tree growth (which may only be partly re-released if the product ends up in landfill).

Pouches (like yoghurt pouches) and lightweight bottles made from 100% recycled plastic have a similar carbon footprint to cartons. New or ‘virgin’ PET (a type of plastic) has a considerably higher carbon footprint than cartons and roughly double the footprint of recycled plastic. 

Glass, however, was found to have the highest carbon footprint across all sizes and categories, with values five to 12 times higher than cartons. Aluminium cans with zero recycled content were comparable to glass, and while much improvement was seen when the cans were made with 70% recycled content, even those cans had a significantly higher carbon footprint than cartons (approximately double).

While the study is comprehensive in the scenarios considered for assessed packaging types, it would not be possible to assess all of the many variables at play. The study therefore made conservative assumptions, such as recycled plastic bottles being manufactured from recycled plastic granulate that is captured and recycled within Australia and New Zealand. Where there is uncertainty, a choice was made in a way that would favour alternative packaging over cartons.

What if the cartons aren’t recycled?

It may be surprising to some, but the study found cartons have the lowest or equal lowest carbon footprint in nearly all scenarios of all packaging assessed, regardless of whether they are recycled or end up in landfill. 

The study considered the end of life of every type of packaging assessed, but for beverage and food cartons it measured the share of cartons sent to landfill versus the share sent to recycling, and the proportion of recycling that occurs in Australia. 

It also looked at what happens to the carton if it ends up in landfill. This includes how much of the carbon stored in the paperboard from the tree-growth phrase is released into the air as carbon dioxide and methane, and the likelihood of those greenhouse gas emissions being prevented from entering the atmosphere through gas capture systems operating at some landfills.

If the worst-case scenario for cartons at end of life is applied (100% of cartons end up in landfill, 0% of landfill greenhouse gases are captured, 50% of the paper in the carton degrades), pouches, lightweight plastic bottles (with or without recycled content) and  bottles made with recycled plastic can have a lower carbon footprint than cartons. However, this is not the most likely scenario and cartons always have a lower carbon footprint than glass and virgin plastic, no matter which end-of-life assumptions are applied.

Carton recycling in Australia

China’s ‘National Sword’ policy in 2018 set strict contamination limits on recyclables, effectively ceasing the export of Australian recycled materials to China. This provides Australia with the opportunity to create a thriving domestic recycling industry.

Tetra Pak is currently negotiating establishing three dedicated carton recycling plants in Australia and New Zealand. A dedicated local recycling system for our food and beverage cartons would improve their environmental impact even further, as well as provide more green jobs. 

Learn more about Tetra Pak’s sustainability goals and initiatives here.

Learn more about recycling and ways you can reduce your environmental footprint at National Recycling Week.