July 23, 2020

expert reaction to paper modelling global plastic cycles and the impact of different interventions

A study, published in Science, modelled global plastic cycles and the impact of different interventions.

Dr Alice Horton, Anthropogenic Contaminants Scientist, National Oceanography Centre (NOC), said:

“This study presents a thorough analysis of the current and future state of plastic pollution in the environment, considering a wide range of production and management factors. Although there are uncertainties about future trends, this study is based on the best available data for plastic production, use and disposal.

“While there is uncertainty about the amount of plastic that will enter the environment in the future this study supports existing evidence that plastic pollution will continue to increase, in line with increasing production and disposal rates. Given that plastics do not readily degrade, this will lead to an inevitable accumulation.

“Plastic is a material that is persistent and can be difficult to manage. Despite a variety of possible scenarios for the future of plastic waste in the environment, scenarios that depend significantly on the actions taken next, even the toughest management approaches proposed here will still lead to a cumulative increase in plastic pollution within the environment.

“This study shows that existing commitments for reducing plastic waste will not be sufficient to prevent this continual increase in plastic pollution. Urgent and extensive interventions in plastic waste production and management are needed. Despite the scale and likely costs of such interventions, such a system overhaul is in fact likely to be more economically viable than the current scenario, due to reduced need for new material production.

Prof Stephen Fletcher, Director of the Revolution Plastics Programme and Professor of Ocean Policy and Economy, University of Portsmouth and member of the UN International Resource Panel, said:

“The researchers have produced an incredibly detailed and well-informed analysis of how plastic moves through the economy and when mismanaged, into the environment in the form of pollution. The scenarios presented in the paper are realistic and offer a clear message for governments, businesses and all of us that much more effort is needed to tackle plastic pollution.

“The key message from this paper is that even with huge changes to how plastics are produced, used, re-used and disposed of, plastic pollution on land and in the ocean is here to stay.

“Although widely speculated, this research confirms the fear that current policy commitments to reduce ocean plastic pollution are inadequate and will only reduce plastic entering aquatic environments by 6.6% per year.

“The ‘system change’ scenario, which produces the greatest reduction in plastics entering nature, is based on a combination of actions that will require a wholesale policy shift towards plastic reduction strategies at the global scale. The extent to which such a shift is realistic is debatable, yet the paper demonstrates that the need for such a shift is urgent.

“The cost of the ‘system change’ scenario is estimated to be 18% lower than ‘business as usual’ for taxpayers. However, many of the actions in this scenario, especially those related to plastic production and product design, will be undertaken by businesses and as such businesses will carry the cost.  It will be important to consider the overall cost and benefit burden across all stages of the plastics life cycle in order to identify the cost of plastic reduction policies.

“As a result of the COVID-19 pandemic, the production of single-use plastic PPE has increased significantly and the use of single-use plastic PPE by the public around the world has led to a huge increase in PPE entering terrestrial and aquatic environments. While the paper does not explicitly discuss the effects of COVID-19 on plastic production and disposal, the improvements it recommends to plastic disposal, collection and recycling will significantly address the challenges presented by COVID-19.”

‘Evaluating scenarios toward zero plastic pollution’ by Winnie W Y Lau et al. was published in Science at 19:00 UK time on Thursday 23^rd July.

DOI: 10.1126/science.aba9475 (2020)

Declared interests

Prof Stephen Fletcher: Lau and Shiran are contributors to a report I am preparing for the G20 on policy options to reduce plastic entering the ocean. I have had no involvement whatsoever in the research presented in the Lau et al, paper in Science.

Dr Alice Horton: No conflicts of interest