Research Centre

Recycled plastic: an undervalued carbon reduction strategy

By June 25, 2020July 7th, 2020No Comments

Although concerns about ocean plastic pollution and global warming continue to grow, the role that recycled plastic could play in mitigating carbon emissions remain largely underappreciated.

Within the last few years, plastic has become the poster boy for environmental degradation. Images of plastic littering shorelines and entangling marine wildlife has rightfully caused public outrage. As a result, the question of how to resolve this issue has permeated society, with some consumers and companies choosing to move away from plastic entirely. While there is no doubt that our consumption patterns must change and industries need to clean up their act, plastic still has a role to play when it comes to addressing an overarching issue of climate warming.

In 2015 the greenhouse emissions from the plastic industry contributed to 4% of the global carbon budget. While this contribution may appear marginal, the World Economic Forum estimates that in a business as usual scenario, emissions from plastic will account for 15% of the global carbon budget by 2050. However, replacing the production of virgin plastic with recycled plastic can significantly reduce emissions, with one study from UC Santa Barbara estimating a half percent reduction to 3.5% for the 2015 scenario. Increasing recycled plastic can thus have a significant positive effect on the carbon footprint of the industry as a whole – but how does plastic compare to other materials?   

Plastic has a lower carbon footprint than other traditional materials 

Many studies suggest that plastic has a lower carbon footprint compared to other more traditional materials such as glass, aluminium and paper. In most cases, it is the production and manufacturing phase of the product lifecycle which accounts for the largest proportion of carbon emissions, contrary to popular beliefs surrounding transportation. 

The fact that plastic has a much lower carbon footprint than glass has been illustrated repeatedly. In 2008 a study by WRAP indicated that PET (plastic) bottles emitted less carbon emissions in the manufacturing phase than glass, which decreased even further when recycled at the end of life. A much more recently published lifecycle study which took into account local management practices, infrastructure and recycling behaviour in Cornwall (UK), also found that substituting PET with glass for beverage bottling would have adverse effects on climate warming and nine other environmental indicators such as ozone layer depletion and marine aquatic toxicity. Another recent study demonstrated that glass emits more than three times as much carbon emissions than PET.  

When it comes to paper and plastic, most studies compare carrier bags. An earlier study delivered by the UK Environment Agency illustrated that we would need to use a paper bag at least three times to neutralise its carbon impact when compared to plastic – for cotton bags that was 131 times! Similar results have been found by a study commissioned by the Northern Ireland Assembly in 2011. At the moment, a direct comparison between the carbon footprint of paper cartons and plastic bottles is lacking. However, it is often highlighted that paper cartons contain mixed materials, such as plastic film, which means they aren’t easily recyclable.   

The case for aluminium cans paints a similar picture – but remains equally complex. A cradle-to-grave assessment of carbonated soft drinks in the UK illustrated that aluminium cans emitted twice as many emissions than PET bottles. A common rationale behind the use of aluminium is that it is widely recycled and contains a high recycled content. Furthermore, considering recent efforts to tackle ocean plastic pollution, many companies are exploring this presumably greener option. Yet by doing so, the danger is that companies could fail to meet their carbon reduction targets, as noted by Reuters:    

“By increasing recycling via cans, companies could fall back in efforts to reduce their carbon footprints, illustrating the tough juggling act they face to keep environmentally conscious investors, campaigners and consumers on-side.”

While the path towards sustainability and a circular economy is far from straightforward and will always be context specific, it is clear that plastic does have an important role to play when it comes to reducing carbon emissions. However, even better than plastic, is recycled plastic.  

Better than plastic, is recycled plastic

Irrespective of the material, using recycled feedstocks has a positive impact on carbon emissions. According to the Sustainable Packaging Coalition:  

“Glass, aluminium, steel, and plastic production processes typically incur lower greenhouse gas emissions when recycled feedstocks are used instead of virgin feedstocks, owing to the fact that the recycling systems that produce those recycled feedstocks are less carbon-intensive than conventional raw material extraction processes….”

The argument for recycled plastic in particular is even stronger – considering that even when increasing the recycled content in other comparable materials, plastic will still achieve a better outcome. For example, this study suggests that a PET bottle with 0% recycled content has a lower carbon footprint than a glass bottle made with 80% recycled content. Glass only performed better than PET with a 23% weight reduction and an inclusion of 90% recycled content. Furthermore, another study illustrated that PET with 0% recycled content released less carbon emissions than glass bottles with 35% recycled content and aluminium cans with 48% recycled content.  

When looking at plastic specifically, an industry study delivered by ALPLA indicated that the production of rPET produced 79% less carbon emissions compared to virgin PET. Similar results were revealed by the Association of Plastic Recyclers who released a report last year illustrating that using recycled plastic reduced greenhouse emissions by 67% for PET and 71% for both HDPE and PP – alongside reducing energy consumption. The results demonstrate both a clear environmental and business incentive for companies. According to Steve Alexander, CEO of APR:  

 “This study shows a win-win for companies who incorporate recycled plastic resin into their new products. They can improve the environmental sustainability of their products and processes and reduce their energy costs.”  

The role of rPET in carbon reduction strategies 

Integrating more recycled plastic content into products and packaging can thus be an effective way to reduce carbon emissions. Yet for companies, the extent to which switching to recycled plastic will reduce emissions remains relative to the packaging contribution to the overall carbon footprint value chain. This means that for food and beverage companies in particular, such a strategy makes logical sense. For example, Coca Cola and PepsiCo note that their packaging can take up a quarter to one third of their total carbon emissions. While for others such as Keurig Dr. Pepper, packaging carbon emissions have a much higher contribution at 43%. 

Incorporating more recycled content into packaging have helped companies achieve carbon neutrality. Niche water brand Belu who have hit this milestone, awarded by the British Standard Institute use 100% recycled plastic in all of their water bottles – making the case that recycled plastic has a lower carbon footprint than other materials such as aluminium cans. Other big names like Evian, who were recently certified carbon neutral by the Carbon Trust, noted that when it came to packaging production, using rPET resulted in 50% lower emissions compared to using virgin PET plastic.  

Reuse, reuse, recycle, recycle 

Although all of the evidence points to the fact plastic has a lower carbon footprint than other traditional alternatives and that using recycled plastic is even better, what happens to the material once it’s fulfilled its original purpose, is what really matters in a fully functioning circular economy. In order to increase recycled content in packaging and other products, there must be a sufficient supply of recycled plastic material available. This calls for a drastic systemic overhaul of our recycling infrastructure, supported by government policies, alongside a change in our perceptions.