31 January 2024

How to keep using (some) plastic without trashing the planet

Estimated reading time: 3 Minutes

Nowadays, plastics are everywhere. They're in our cars, clothes, food packaging, and even in the insulation in our homes. We've gotten so good at making plastics that, in 2015, we produced over 380 million tons of them. However, plastics bring forth a big problem: they're hard to dispose of properly. It’s estimated that in the 2010s, the global economy lost about 80% of our plastic waste to the environment instead of feeding it into waste disposal systems like recycling plants, landfills, or incinerators.

As well as challenges with waste management, plastics contribute to global warming by releasing significant amounts of carbon dioxide. In fact, the annual emissions released from the plastic lifecycle is equivalent to the total emissions of Germany, the UK, and France combined. 

Smith School researchers are working on ways to make our plastic system more sustainable and to reduce the amount of plastic we use. This is critical work to decrease pollution and reduce emissions. Creating a circular economy for plastics needs to consider every stage of a product's life – from creation to disposal – while trying to keep useful plastic in the economy and out of the environment as much as possible. 

To tackle this ‘wicked problem’ we have joined forces with the Oxford Chemistry Department and Faculty of Law, as part of the Oxford Martin School's Programme on the Future of Plastics.

The problem is that plastics, while contributing hugely to global pollution and greenhouse gas emissions, are extraordinarily useful.
Cameron Hepburn, Battcock Professor of Environmental Economics

Released on 31 January 2024 in Nature Sustainability, new research from the team finds that creating a circular economy for plastics in order to reduce their negative impacts is possible, but only if we take bold steps to change the current system. 

We identified four main recommendations to help make plastics sustainable: 

  • Significantly cut down the amount of plastic we use 
  • Invest in better waste management infrastructure, especially for recycling 
  • Design plastics to be easier to recycle 
  • Use sustainable materials to make plastic products

We explore these recommendations in more detail below.

A circular economy for plastics requires managing demand, recycling, and switching to renewable raw materials

1.  Reduce plastics demand by 50%

A critical component of reducing plastics pollution and emissions is to significantly decrease the amount of plastics we use. The research team estimates that plastic demand needs to be cut by halve by 2050 to make a circular economy for plastics feasible. 

A combination of approaches can help reduce plastic demand, including re-designing products to require less plastic (for example, by removing unnecessary packaging, substituting alternative materials for plastics, and choosing plastics with a longer lifespan and higher recyclability).

2. Ensure 95% of plastics are recycled 

A circular economy for plastics requires 95% of plastics to be recycled by 2050. High recycling rates are important because they replace new feedstocks with materials already in the plastic system, which reduces pollution and demand for raw materials. Our research team estimates that recycling 95% of plastic will provide around 85% of the materials needed to make new plastics. To make recycling extra effective for plastic production, we can design products so they can easily be separated into different components. 

However, making sure that plastics are easy to separate and recycle is only half the problem. Around two thirds of municipalities globally do not have proper waste management systems, with particular problems in low- and middle-income economies. Significant investment is needed to ensure that infrastructure in these countries can manage the high volumes of recycling needed in the future. 

3. Switch to 100% renewable plastic feedstocks

One of the most effective ways of reducing emissions from plastic is to change what plastics are made of. Currently, most plastic is made of oil. However, scientists have developed ways of making plastic from biomass, which includes materials like leaves, branches, fruits, and vegetables. While this is a great way of reducing emissions, we must be careful that the land used for biomass for plastics does not interfere with food production, conservation, or biodiversity. 

4. Minimize environmental impacts

Minimizing environmental impacts requires several major shifts. Firstly, 100% of the energy used in plastics manufacturing must be renewable by 2050. Secondly, the types of plastics produced must minimise the potential for pollution. This means avoiding plastic types that are oxo-degradable or create microplastics, as these can damage the health of humans and the environment. Finally, we need to make sure that regions with insufficient waste management infrastructure have access to biodegradable plastics, so that any plastic leaking into the environment can break down safely and effectively. 

Isolated solutions cannot fix the plastics problem

To cut down on plastic emissions and pollution, we need a combination of actions that work together. One main branch of these actions must focus on phasing out petrochemicals, for example by removing subsidies to oil and gas infrastructure. A second element needs to focus on increasing the cost competitiveness of biomass feedstocks, for example by encouraging R&D of plant-based plastics manufacture and designing low-impact plant cultivation systems suited to different ecosystems around the globe. A critical third branch must invest in waste management facilities in low- and middle-income economies. It is particularly important for global efforts on plastic to keep in mind the differences between regions: investment into low-and middle-income economies is important, and needs to consider a large informal sector associated with waste management.

Finally, global cooperation is essential to coordinate these interventions. In May 2022 the United Nations started to negotiate a legally binding international treaty to tackle plastics pollution, aimed at addressing the full lifecycle of plastics from production to end-of-life. These instruments are promising steps toward a coordinated international response to plastics pollution.