In This Issue
The Bridge: 50th Anniversary Issue
January 7, 2021 Volume 50 Issue S
This special issue celebrates the 50th year of publication of the NAE’s flagship quarterly with 50 essays looking forward to the next 50 years of innovation in engineering. How will engineering contribute in areas as diverse as space travel, fashion, lasers, solar energy, peace, vaccine development, and equity? The diverse authors and topics give readers much to think about! We are posting selected articles each week to give readers time to savor the array of thoughtful and thought-provoking essays in this very special issue. Check the website every Monday!

Engineering Interventions to Reduce Plastic in the Environment

Monday, February 15, 2021

Author: Jenna R. Jambeck

In 1970 just over 30 million metric tons of plastics were produced globally for use; now that number stands at 359 million metric tons (Geyer et al. 2017[1]; PlasticsEurope 2019). As of 2017, a cumulative 8.3 billion metric tons of plastics had been produced.

Plastics are unquestionably useful. And many consumer items are made from plastic because the needed monomers, like ethylene, are available at very inexpensive prices. But too many of them end up in the waste stream.

Plastics: An Unsustainable Convenience

Because 40 percent or more of plastics are used in packaging and other single-use items, 6.4 billion metric tons of plastics had already become waste by 2015. Only 9 percent of plastic waste has been recycled on average globally, and 12 percent has been incinerated. This means that 79 percent ended up in landfills, mismanaged on land, or in the ocean. Plastics are now found everywhere in the environment, from the deepest part of the ocean to the highest peaks in the world and all points in between.

Between 5 and 13 million metric tons of plastic enter the oceans each year from mismanaged waste (Jambeck et al. 2015; Lebreton and Andrady 2019), equal to about a dump truck of plastic entering the world’s oceans every minute. Globally, hundreds of seabirds, whales, fish, shellfish, and turtles are impacted each year by plastic, whether from ingestion or entanglement (Wilcox et al. 2013, 2015; Worm et al. 2017).

Even with current mitigation practices, improved waste management systems, and cleanup, new research shows that 20–53 million metric tons of plastic will enter all aquatic systems per year by 2030. Much more aggressive reductions, improvements, and cleanup are needed (Borrelle et al. 2020).

Role of Engineers and Engineering

Effective engineering involves not just designing a construction project or technical intervention but a systems approach that accounts for diverse people and communities. It needs to incorporate sociotechnical designs, like improved waste management systems that include the informal waste management sector, which keeps plastic out of the ocean by recycling it in many countries around the world, as well as deep stakeholder engagement from start to finish, acknowledging that community leaders and members have local and native knowledge that not only contributes to but improves designs and approaches.

Engineers can help not just by developing more and improved waste management infrastructure but by decoupling waste generation from economic growth by leveraging technology with context-sensitive designs. Technology and shipping and logistics systems mean greater availability of reusable packaging. For example,

  • just as milk used to be delivered in glass bottles that were returned and reused, individuals can now purchase a stainless steel ice cream container (available online) that can be returned and refilled;
  • reusable cups and to-go containers can be tracked and associated with users for automatic payment with radio frequency identification (RFID); and
  • reusable containers can be refilled with trusted brands from a truck that travels through a community.

If packaging is needed, it can be made from bio-degradable materials, such as new polymers like poly-hydroxyalkanoates (PHA) that behave like traditional plastics in specifications but biodegrade at their end of life.

In addition, mobile app technology, available to billions of people around the world, can be used for on-demand collection of waste and recyclable material as well as reports of litter with, for example, Marine Debris Tracker, to inform upstream interventions for common items found in the environment and on the coastline. This information can empower communities with data to make decisions about ways to reduce marine litter that fit their specific context.

These are some of the ways both new and “old” systems can enhance efficiency and reduce waste in today’s high-tech society.

Concluding Thoughts

People could be more thoughtful about where, when, and how they use and dispose of plastics. But to move forward to, for example, a circular economy, entire systems need to be engineered and changed. Can we take cues from nature where every output becomes an input in each system?

As engineering proceeds over the next 50 years, it is critical to take a diverse and holistic approach, while learning lessons from the past to engineer the future.

References

Borrelle SB, Ringma J, Law KL, Monnahan CC, Lebreton L, McGivern A, Murphy E, Jambeck J, Leonard GH, -Hilleary MA, and 10 others. 2020. Predicted growth in plastic waste exceeds efforts to mitigate plastic pollution. Science 369(6510):1515–18.

Geyer R, Jambeck JR, Law KL. 2017. Production, use, and fate of all plastics ever made. Science Advances 3(7):e1700782.

Jambeck JR, Geyer R, Wilcox C, Siegler TR, Perryman M,  Andrady A. 2015. Plastic waste inputs from land into the ocean. Science 347(6223):768–71.

Lebreton L, Andrady A. 2019. Future scenarios of global plastic waste generation and disposal. Palgrave Communications 5(1).

PlasticsEurope. 2019. Plastics – the Facts 2019: An Analysis of European Plastics Production, Demand and Waste Data. Brussels.

Wilcox C, Hardesty B, Sharples R, Griffin D, Lawson T, Gunn R. 2013. Ghostnet impacts on globally threatened turtles: A spatial risk analysis for northern Australia. Conservation Letters 6(4):247–54.

Wilcox C, Van Sebille E, Hardesty BD. 2015. Threat of plastic pollution to seabirds is global, pervasive, and increasing. Proceedings, National Academy of Sciences 112(38):11899–904.

Worm B, Lotze HK, Jubinville I, Wilcox C, Jambeck J. 2017. Plastic as a persistent marine pollutant. Annual Review of Environment and Resources 42(1):1–26.

 


[1]  Further statistics in these first three paragraphs are from Geyer et al. (2017).

 

About the Author:Jenna Jambeck is the Georgia Athletic Association Distinguished Professor in Environmental Engineering, a National Geographic Fellow, associate director of the New Materials Institute Center, and lead of the Center for Circular Materials Management, all at the University of Georgia.