Plastic planet

Plastic waste is so pervasive that there'll never be only one solution to the problem, which is why a multidisciplinary team from across The Bartlett and UCL are trying to tackle it from all angles.

“Single-use plastics have captured the attention of the media, but the packaging is only a small percentage of the plastics we use – they are used in construction, electronics, agriculture, and almost every other sector.” 

Domenech is working as part of a team at UCL on an 18-month project housed at the university’s Institute of Making that aims to bring a holistic, multidisciplinary approach to this pressing issue. Funded by the UK Research and Innovation, it brings together researchers from a range of fields – from chemistry and engineering to behavioural sciences – in an effort to design out plastic waste from our systems of production, using a combination of science, infrastructure and policy. 

“We would like to provide clarity so we can judge what kind of policy interventions, consumer-led actions or infrastructure could make the biggest impact in creating a more circular economy – because we are very far from that at the moment,” Domenech says. 
 
Mark Miodownik, Professor of Materials and Society in the UCL Mechanical Engineering Department, is leading the project. “There is no one solution to the plastic waste problem, so we came to the realisation that you need a multidisciplinary approach to have any chance of tackling it,” he says. The strategy is, therefore, threefold: apply biological principles to improve the biodegradability of difficult-to-recycle plastics; put in place ways to ensure more plastic is recycled or reused; and improve our public, commercial and industrial habits when it comes to waste generation and reduction.

Cracking the chemical equation

On the first of these research fields, work is underway on considering what enzymes and bacteria might help with plastic biodegradability, as well as on assessing the impact of plastics on the natural environment over its lifecycle. “The assessment will provide estimates in terms of CO2-equivalent emissions, energy consumption, and effects on humans and the biosphere,” says Paola Lettieri, Professor of Chemical Engineering at UCL’s Faculty of Engineering Science.

Miodownik says there is a lack of technological solutions to deal with the plastics we currently use, but points out that the solution is not as simple as just creating bioplastics – something that has become an increasing focus in the design world. “What we are currently doing is asking the question, are biodegradable plastics the answer or the problem? The conclusion so far is that it’s well meaning, but not very helpful.”
 
The barrier is not so much that these plastics do not biodegrade but that the system doesn’t exist for that to happen. “Biodegradable plastic, if it’s put into the recycling, contaminates plastic for recycling,” he says. “If it’s put in the bin, it goes to landfill or gets burned. And these bioplastics don’t tend to biodegrade in any short time period, even if you put them in your compost.” So, what is the solution? “The first thing we would say is stop promoting biodegradable plastics until we understand them better,” says Miodownik. “A more environmental solution is to reduce the use of plastics or to use recyclable plastics.”

Biowaste plastics also consume land and water and, perhaps a bigger issue with plastics in general, is that the energy that goes into making plastics are not renewable, which contributes to our overall carbon footprint. “The feedstock for the plastics needs to come from bio-based renewable resources,” Miodownik says. Lettieri’s work will look into the gains of decoupling plastics from fossil feedstocks, evaluating the energy consumption of the process chains involved in the manufacturing of new biopolymers developed within the project. 

Turning the system circular

Even when it comes to recyclable plastics, the problem is systemic rather than simply an issue with the material itself. Domenech’s work centres very much on this aspect of the problem. She is conducting a material flow analysis to work out how much plastic we consume, at what stage plastics become redundant and enter the waste cycle, where they end up, where the leakages in the system are and whether or not there is adequate infrastructure in place to deal with these materials. “We are trying to have a picture of the whole system to understand how we intervene to make it circular,” she says.  

A similar Europe-wide study that Domenech worked on found that only 6% of plastics currently re-enter the system, despite 40% of them being recycled. She estimates that the findings in the UK will be similar, but that her analysis will allow for a more detailed picture and therefore targeted solutions. “I think it’s about placing more responsibility on the manufacturers and producers of plastics, so they are aware they’re going to be financially responsible for the end of life of those products,” she says. “That might promote better design of products that can be more easily recycled.” 

Breaking bad behaviour

The final aspect of this project in behavioural change – how the problem of plastic is communicated to the public and how people can be encouraged to develop better habits when it comes to recycling. Domenech explains: “How do we create more clearly identifiable labels so that citizens can understand the different types of plastics? What can they do at home to increase recycling?” 

Susan Michie, Professor of Health Psychology and Director of the Centre for Behaviour Change at UCL, says her strand of the project will assess motivation, capability and opportunity when it comes to interventions to tackle the problem of plastic waste.  “We are considering using UCL as an experimental laboratory to reduce single-use plastic brought onto campus – water bottles, coffee cups, industrial packaging, for example – and to ensure that waste is appropriately recycled, targeting both producers and consumers of plastic on campus,” she says. 

UCL East – the university’s new campus in Stratford, East London – provides opportunities to conduct these experiments. However, Miodownik points to the difficulties in making these changes in a context that is set up to rely on disposables – for example, the lack of washing-up facilities for reusable cutlery and crockery. Where there are financial incentives to bring your own cups to a cafe, he observes, most people still prefer the convenience of disposables. “How  would we shift people sufficiently?” he asks. “We are hoping to trial a reusable cup system where reusable cups are available at the point of sale then a third party collects them, cleans them and returns.”

This is because behavioural change, he says, is promoted when you make things really simple for people to do. “You shouldn’t ever have to look at what you are recycling,” Miodownik says. “All packaging should be recyclable and all of it should go into your recycling bin. It’s a question of weaning companies off the non-recyclable packaging and getting local authorities to invest in recycling facilities.” One positive development he points to is a government consultation on putting in place rules to ensure that if a business creates packaging, it also has to put money into collection and repurposing.

Part of the project at UCL involves working with the waste collection industry, retailers, brands, policy-makers, local government and charities, to help them design out plastic waste. Several of these sit on the project’s advisory board as part of a steering committee, which will ensure the legacy of the project after the 18-month funding comes to an end.

Ultimately, Miodownik says, it’s important not to demonise plastic, which fulfils an important function when it comes to food preservation and preventing waste. But the most crucial message he feels should be conveyed is that there’s only so much we can do to solve the problem without hugely reducing the scale of our current plastic consumption. Which means there has to be a concerted drive to eliminate plastic. “Our interim conclusions in the face of this difficult environmental situation is to reduce at all costs, not to replace,” he says.

Domench agrees: “Even if recycling rates improve, the level of circularity of the system will still be relatively limited, so we have to also look at what we can do to reduce overall demand for plastic or try to find solutions that promote more reuse of materials or other options,” she says. “In 18 months, we will only be able to scratch the surface of the problem.”

Go against the flow

Material Flow Analysis is one of the methods that will be used by the ISR's Teresa Domenech and the UCL Plastic Waste Hub to analyse the scale and implications of the plastic waste problem in Britain. A previous study by fellow ISR researcher Wan-Ting Hsu applied the same approach to take a one-year snapshot of plastic waste flow across Europe in 2014. From this, she then built a model that estimated the change in habits between 1960 and 2040 when it came to plastic consumption, recycling and reuse.
 
Hsu's results showed that around 67 million tonnes of plastic polymers were produced and about 69 million tonnes were consumed across different applications in Europe in 2014. The recycling rate was revealed to be around 38%, but only 9% of this recycled plastic was eventually used to produce new products. This was primarily because of the amount of material lost during the recycling process, as well as the export of plastic and leakage to the environment. 

Against a backdrop of continuously growing plastic production, the researchers hope that these insights will allow the development of a comprehensive understanding of plastic flows and stocks, which can then provide decision-makers with an evidence-based model to develop a more circular economy when it comes to plastic.