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, published in Science, 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.
The final round of negotiations for the UNEP Global Plastics Treaty is set to take place in South Korea from 25 November to 1 December 2024.
The Science Media Centre asked third-party experts to comment.
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.”
Conflict of interest statement: 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.”
No conflicts of interest.