PHOTO: Mihaly Koles/Unsplash
PHOTO: Mihaly Koles/Unsplash

EXPERT REACTION: Global plastic waste to double by 2050, study says

Embargoed until: Publicly released:
Peer-reviewed: This work was reviewed and scrutinised by relevant independent experts.

A new modelling study says global plastic waste will double by the middle of the century if we stick to business as usual. However, a mix of policies could slash it by 90%. The study also found that greenhouse gas emissions from plastic production and waste management are set to grow by 37% over the same period. The team simulated eight interventions currently being considered in the United Nations plastic pollution treaty, finding that implementing just four could reduce mismanaged plastic waste by roughly 91% and plastic-related emissions by a third.

Journal/conference: Science

Research: Paper

Organisation/s: University of California, Berkeley

Funder: Benioff Ocean Science Laboratory; March Marine Initiative; Harris Family Charitable Gift Fund

Media release

From: AAAS

Without intervention, global plastic waste could double by 2050, a new machine learning study predicts. However, according to simulations by the study’s authors, a mix of policy interventions could cut plastic waste by more than 90% and it could cut plastics-related emissions by a third. With UN treaty negotiations underway, these findings provide a crucial blueprint for tackling the plastic crisis. Plastic production has increased relentlessly for decades, leading to surging plastic waste generation and environmental mismanagement. As plastic degrades, it fragments into micro- and nano-plastics, which harm ecosystems globally – from the Arctic to deep ocean habitats – and pose significant health risks, including heightened cancer risks, cardiovascular disease, and reproductive issues. The plastic lifecycle also intensifies climate change through emissions from oil and gas extraction, production, and waste processing. The disproportionate plastic waste burden on the Global South and the frequency of situating plastic facilities near marginalized communities have sparked pressing environmental justice concerns. Recently, there has been global momentum to address these issues, culminating in a 2022 United Nations resolution to negotiate a legally binding treaty to curb plastic pollution.

To help in this effort, Samuel Pottinger and colleagues developed a novel machine learning model to forecast trends in global plastic production, trade, and waste management to 2050. They also simulated the effects of eight plausible policy interventions to mitigate waste and emissions. Pottinger et al. found that, without interventions, annual mismanaged plastic waste is anticipated to almost double by 2050, reaching 121 million metric tons. Concurrently, annual greenhouse gas emissions from the global plastic system are projected to rise by 37% over the same period. However, the authors also show that a combined policy intervention approach involving a production cap, recycling mandate, packaging tax, and infrastructure investment could reduce mismanaged plastic waste by up to 91% and decrease 2050 plastics-related emissions by about a third. “Collectively, these observations provide timely insight into how to maximize the impact of the UN plastic pollution treaty both as it is being drafted and over the longer time horizon of its implementation,” write Pottinger et al. “It is clear from these results that, with sufficient political will, there is enough technical potential to dramatically reduce mismanaged plastic waste and meaningfully address some of the more insidious associated issues.”

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Expert Reaction

These comments have been collated by the Science Media Centre to provide a variety of expert perspectives on this issue. Feel free to use these quotes in your stories. Views expressed are the personal opinions of the experts named. They do not represent the views of the SMC or any other organisation unless specifically stated.

Professor Sally Gaw, School of Physical and Chemical Sciences, University of Canterbury, comments:

Management of plastic waste at the end of life of products is a pressing environmental challenge. Every year around 430 million metric tons of plastic is produced globally, of which only 20% is recycled. 

"This new paper in Science by Pottinger et al has used modelling to project the future growth in mismanaged plastic waste, and to determine the potential impacts of policy interventions proposed to be included in the United Nations Treaty to end plastic pollution currently being negotiated. Their modelling shows that multiple policy interventions in combination will be required to significantly reduce mismanaged plastic waste and that, without policy intervention, the amount of mismanaged plastic waste will double by 2050 reaching an estimated 121 million metric tons.

"This modelling highlights that reducing mismanaged plastic waste will not be a quick fix. Reducing the amount of mismanaged plastic waste in the environment will have the additional benefits of reducing greenhouse gas emissions and reducing the release of hazardous chemicals used in the manufacture of plastics.

Last updated: 15 Nov 2024 8:01am
Declared conflicts of interest:
Professor Sally Gaw has received MBIE funding to research the impacts of plastics.

Dr Olga Pantos, Science Leader, Institute of Environmental Science and Research (ESR), comments:

The paper focuses on the role of policies to reduce the mass of mismanaged waste, and demonstrates that some of the proposed policies will effectively reduce both the levels of mismanaged waste and levels of greenhouse gas emissions associated with it. This is certainly encouraging, however the other ‘end-of-life’ fates of plastics are immense, and only getting bigger. They also pose significant environmental and human health impacts and the most important and impactful thing we can do is to significantly reduce our use of plastics and improve the safety and sustainability of the plastics that are essential.

"The harm plastics can cause both humans and the environment occurs along its whole lifecycle, not just at end of life once an item has served its purpose, and certainly not only if it has been mismanaged. It is important to remember that every bit of plastic we refuse or don’t voluntarily bring into our lives reduces harm all the way back to the point where fossil fuels are drawn out of the ground to make the plastic polymer. Doing so also reduces the need for all the other chemicals used in plastic production (of which approximately 4000 are known to have negative human health effects), reducing emissions from transport, removing the risk of the plastic or plastic item becoming pollution on its long journey from factory to your door. This reduction in the production and use of plastics also brings with it a reduction in the formation and release of nano- and microplastics, which constitutes mismanaged plastic pollution that can occur during manufacture, use and at the end-of-life, both from managed and mismanaged disposal. This form of plastic pollution is now ubiquitous in all natural environments tested, in our food, water and the air, and increasingly being identified in human tissues.

"We are facing a triple planetary crisis – climate change, biodiversity loss, and pollution. Plastic is a major contributor and amplifier of all three. It is essential that an ambitious and effective treaty, based on scientifically robust evidence, is achieved to ensure a safe and sustainable future for generations to come.

Last updated: 15 Nov 2024 7:59am
Declared conflicts of interest:
No conflicts of interest

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