Considering consumer behavioral norms is important to sustainable design. This Editorial discusses the need to incorporate behavioral patterns into product design and the role that the chemical engineering community can play in fostering a more informed understanding of sustainability among consumers.
The holiday season has arrived in some parts of the world. Despite being a period traditionally associated with gift-giving and togetherness for those who celebrate, in recent decades festive periods around the world have also become increasingly linked to a surge in consumer spending. For example, events such as Cyber Monday posted record sales this year, with a year-over-year increase of more than 7%, bringing online spending to US$13.3 billion (ref. 1).

Chemical engineering has enabled the technological capacity to meet this growing demand for consumer goods; however, these demands have led to unintended consequences, some of which have imposed severe environmental strain. Consider plastic waste: the use of plastic products has driven an increase in waste production that has consistently outpaced population growth over the past half-century2.
The relationship between chemical engineering, goods production and sustainable resource use is both complex and consequential. While the practice has been instrumental in enabling production capacity, chemical engineering has also been fundamental in recent efforts to mitigate unsustainable consumption. Traditional process design criteria are often based on chemical or physical constraints, but here we argue that there is a growing need for the field to consider human behavior as an element of sustainable design. This includes recognizing that consumer behavioral patterns can also impose constraints on design optimization and embracing a collective effort to raise public awareness of both environmental challenges and emerging engineering solutions.
How consumers understand and engage with sustainable practices can dramatically impact the effectiveness of a product or technological solution. For example, a 2018 life-cycle assessment of reusable grocery bags found that a conventional cotton tote bag may need to be reused thousands of times to achieve the same environmental impact as a traditional low-density polyethylene grocery bag3. While the exact comparison is rather complex and depends on many factors, the general idea suggests that if consumers dispose of reusable bags before reaching the reuse threshold, such products may have a net negative impact on environmental indicators despite being developed as sustainable alternatives. In other words, process considerations such as the break-even time for bag reuse above may not be the relevant timescale if the time over which consumers replace the alternative is shorter.
The success of technical engineering solutions to sustainability challenges is also linked to consumer norms, which vary over both time (behavioral trends) and space (regional and global geographical variations). A recent Article in Nature by Cottom and co-workers highlights geographical variation in waste management by showing that plastic emissions, defined as uncontrolled material in the environment, are dominated by littering in the global north and uncollected waste in the global south4. Similarly, as argued by Niinimäki and co-workers in Nature Reviews Earth & Environment, the rise of consumer demand for high-turnover clothing — so-called fast fashion — has contributed to a surge in largely synthetic textile waste production over the last two decades5. Addressing such challenges is likely to require not only technological innovation, but also policy reform and a general cultural shift toward more sustainable consumption practices.
While some aspects of consumer behavioral patterns can be included in process, techno-economic and life-cycle analyses simply as mathematical constraints, it is important to consider the role of the chemical engineering community in helping the public understand the part they play in executing (or hindering) solutions to environmental challenges. A well-known case where scientific communication helped spur public action is that of the degradation of Earth’s ozone layer by man-made chlorofluorocarbons (CFCs). About a decade after the 1974 publication by Molina and Rowland in Nature, the Montreal Protocol to phase out CFCs was adopted on the international stage6. Rowland would later remark, “Is it enough for a scientist simply to publish a paper? Isn’t it a responsibility of scientists, if you believe that you have found something that can affect the environment, [...] to actually do something about it, enough so that action actually takes place?”7.
Solving modern environmental challenges through technological innovation alone threatens to be intractable. Pairing scientific progress with consumer education is essential to most effectively translate technical advances to real-world progress in sustainable process design — not only during the holiday season, but throughout the entire year.
References
Venugopal, A. & McLymore, A. Cyber Monday US spending breaches $13 bln as steep discounts online drive sales. Reuters https://go.nature.com/49zL8kg (3 December 2024).
Geyer, R. et al. Sci. Adv. 3, e1700782 (2017).
Life Cycle Assessment of Grocery Carrier Bags (The Danish Environmental Protection Agency, 2018); https://go.nature.com/3VArY80
Cottom, J. W., Cook, E. & Velis, C. A. Nature 633, 101–108 (2024).
Niinimäki, K. et al. Nat. Rev. Earth Environ. 1, 189–200 (2020).
Molina, M. J. & Rowland, F. S. Nature 249, 810–812 (1974).
Wilson, J. & Vasich, T. How UCI saved the ozone layer. UC Irvine News https://go.nature.com/3BAfgPS (11 January 2023).
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The human element of process design. Nat Chem Eng 1, 788–789 (2024). https://doi.org/10.1038/s44286-024-00165-8
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DOI: https://doi.org/10.1038/s44286-024-00165-8