The research team, led by Chunyan Si and Petar Sabev Varbanov of the Pázmány Péter Catholic University network along with colleagues including Yee Van Fan and Lidija Čuček, focused on the European Union’s twenty-seven member states, where packaging accounts for 39 percent of all plastics conversion. Their model simulates the period from 2018 to 2030, beginning with the year the EU’s single-use plastics restrictions took effect and China’s import ban on plastic waste reshaped global recycling flows. Four materials compete within the simulation: conventional low-density polyethylene, polylactic acid bioplastic derived from corn, kraft paper, and natural cotton, each with distinct weights, lifespans and end-of-life pathways.

What distinguishes this framework from a conventional life cycle assessment is its treatment of time and feedback. The model is built from 144 interconnected system elements organised into five subsystems: demand, production, consumption, end-of-life management and environmental impact. Causal loop diagrams map the reinforcing and balancing feedbacks, such as how growing reuse inventories of durable bags suppress new production, which in turn lowers emissions until those bags wear out and demand surges again. Stock-flow equations then translate these relationships into quantitative projections, with 74 equations and 70 parameters drawn from official statistics, technical reports and published life cycle inventories.

The reuse assumptions are grounded in observed behaviour rather than idealised scenarios. Kraft paper bags, which last roughly a year and a half under favourable conditions, are assumed to survive between one and three uses before moisture and handling destroy them. Cotton bags, with an estimated three-year lifespan, are credited with 50 to 150 uses. Plastic and bioplastic bags remain strictly single-use, reflecting prevailing retail practice. Crucially, the functional unit is a single carrier bag of equivalent 15-litre capacity, so the model compares services rather than objects, and material-specific mass differences, from 18 grams for plastic to a hefty 456 grams for cotton, are explicitly accounted for in every calculation.

Validation against historical data from 2018 to 2021 lends the projections credibility. Mean error rates for population, bag demand, waste generation and landfill accumulation all fell within plus or minus 6 percent, and the model reproduced landfill trends with a coefficient of determination of 0.81. Weaker correlations for bag demand and waste generation reflect the limited year-to-year variation in the short historical record rather than structural flaws, the authors note. With the model thus anchored, the team ran single-material strategies, in which one bag type serves the entire market, and four mixed scenarios in which the plastic share declines in steps of 20 percent, culminating in a consumer-preference scenario with 50 percent cotton informed by European survey data.

The single-material results upend several popular assumptions. Polylactic acid bioplastic emerges as the clear environmental winner on the two metrics studied, cutting greenhouse gas emissions by 42.3 percent and energy consumption by 55.4 percent relative to conventional plastic by 2030, figures consistent with independent life cycle literature. Yet the authors caution that bioplastics accounted for only 0.5 percent of global plastic production in 2022, and a full substitution would raise global agricultural land use by an estimated 1.2 percent, competing with food production. Kraft paper, meanwhile, performs worse than plastic on emissions under every reuse level tested, remaining 2.4 to 20.1 percent higher by 2030, because paper manufacturing emits up to seven times more greenhouse gases per unit than plastic production, though its energy consumption is generally lower thanks to plastic’s fossil-intensive feedstocks.

Cotton tells the most dramatic story of all. Producing one cotton bag consumes roughly the energy of manufacturing 400 conventional plastic bags, so at low reuse rates of 50 uses the cotton pathway ends 2030 with emissions 49.7 percent above the plastic baseline. Push reuse to 150 uses, however, and the picture inverts: emissions fall 18.9 percent below baseline and energy consumption drops by 47.2 percent. The model also captures the characteristic oscillations of reusable systems, in which emissions and energy use rise as new bags are produced, fall once reuse inventories saturate demand, then climb again as bags reach the end of their lifespan and production must resume.

The mixed-material scenarios reveal that phasing out plastic alone is not enough. Under low reuse conditions, every substitution scenario produced higher emissions than the all-plastic baseline, with the cotton-heavy Scenario 4 reaching 37.7 percent above baseline. Under high reuse, the same scenarios delivered emissions reductions of 8.5 to 20.3 percent. Energy consumption, by contrast, fell in every scenario at every reuse level, ranging from 5.6 to 45.1 percent below baseline, because plastic’s petroleum-based raw materials are so energy-intensive. The lesson is stark: reducing plastic production and raising reuse intensity must proceed together, or well-intentioned substitution can backfire on the climate.

Sensitivity analysis sharpened the policy implications further. Shifting 5 percent of waste from landfill to recycling cut simulated emissions by 5.63 percent and energy use by 6.47 percent, whereas an equivalent shift to incineration changed outcomes by less than half a percent. The most aggressive waste-management improvement tested, a 10 percent recycling increase combined with a 15 percent landfill reduction, lowered emissions by 11.10 percent and energy consumption by 13.34 percent. Reuse frequency proved even more powerful: extending cotton bag reuse from 50 to 150 uses reduced emissions by 45.8 percent, dwarfing the effects of any macroeconomic parameter. Even accounting for degraded recycled material quality, which raised emissions by up to 12.97 percent at the lowest substitution factor tested, the relative ranking of scenarios held firm.

The authors acknowledge limitations, including the exclusion of retail distribution, secondary household uses of plastic bags, and impact categories beyond emissions and energy such as land use and water depletion. Still, the framework offers policymakers a transferable tool for testing packaging strategies before committing regulatory resources, and it delivers a clear message for consumers: the environmental value of a reusable bag is not fixed at the factory gate but earned, use by use, in the years that follow. A tote bag abandoned in a cupboard is, by this accounting, one of the most carbon-expensive objects a household can own.

Subject of Research: System dynamics simulation of greenhouse gas emissions and energy consumption across plastic, bioplastic, paper and cotton carrier bag life cycles in the EU-27

Article Title: System dynamics modeling for simulating greenhouse gas footprint and energy consumption of plastic packaging and its alternatives

Article References: Si, C., Fan, Y. V., Čuček, L., Teng, S. Y., Dokl, M., Lendvai, L., Kravanja, Z., & Varbanov, P. S. (2026). System dynamics modeling for simulating greenhouse gas footprint and energy consumption of plastic packaging and its alternatives. Cleaner Engineering and Technology, 34, Article 101305. https://doi.org/10.1016/j.clet.2026.101305

Image Credits: AI Generated

DOI: 10.1016/j.clet.2026.101305

Keywords: system dynamics, life cycle assessment, plastic packaging, carrier bags, bioplastics, reuse, greenhouse gas emissions, energy consumption, circular economy, EU policy, recycling, cotton tote bags

The research is grounded in an in-depth qualitative case study of the Brazilian plastic packaging sector, one of the largest in the Global South. The empirical base consists of ten semi-structured interviews with actors spanning the value chain, from packaging producers to recyclers and institutional stakeholders, supplemented by twenty-seven secondary sources including webinars, lectures, and industry events. The analytical coding structure was applied to identify patterns of upgrading across firms and their networks. Full interview recordings remain confidential because the combination of participants’ professional positions and accounts of specific circular initiatives could allow deductive identification, but de-identified excerpts supporting the findings are reported in the manuscript.

The study’s central contribution is the identification of three distinct and markedly uneven pathways of circular upgrading. The first is design and material upgrading led by focal firms, typically the large packaging manufacturers and brand owners with the resources to reformulate products, substitute conventional polymers, and introduce mono-material constructions. The second is process upgrading, in which firms improve internal efficiency and tighten control over material loops within their own operations. The third is network-dependent recovery and recirculation, which requires coordinated action across collectors, cooperatives, recyclers, municipalities, and regulators. The crucial asymmetry, the authors find, is that the first two pathways sit largely under the control of individual firms, while the third depends on collective infrastructure and institutional arrangements that Brazil, like many Global South economies, does not reliably provide.

The theoretical machinery behind this conclusion comes from the governance framework of global value chains. In that framework, the complexity of transactions, the ease with which they can be codified, the capabilities of suppliers, and the degree of coordination required jointly determine how value chains are governed, from arm’s-length markets to captive and hierarchical relationships. Costa and Scur extend this logic to circularity. Circular upgrading in design and materials, for instance, is tractable for focal firms because transactions with suppliers can be specified, codified, and monitored. By contrast, circular upgrading in recovery and recirculation involves transactions of high complexity that resist codification and depend on capabilities that are dispersed and unevenly distributed across informal waste pickers, small recyclers, and municipal systems.

Brazil’s institutional landscape plays a decisive role in these outcomes. The country’s National Solid Waste Policy, established by federal law in 2010, introduced the principle of shared responsibility for the product lifecycle and mandated reverse logistics systems, yet implementation has been fragmented and uneven. A 2021 law created incentives for recycling through fiscal mechanisms, but the researchers find that regulatory limitations continue to constrain network-dependent pathways. Informality compounds the problem: millions of waste pickers, or catadores, perform the frontline work of material recovery, often outside formal contracts, without guaranteed quality standards, and with limited bargaining power in the value chain. This informal foundation keeps the recovery loop partially functional but unstable, undermining the traceability and consistent recyclate quality that industrial buyers require for circular inputs.

The findings illustrate a broader pattern in Global Value Chain scholarship: power is unevenly distributed, and focal firms can impose requirements on suppliers while remaining insulated from the weakest links. In the Brazilian case, focal firms can demand recyclable designs and cleaner inputs from their supplier base, and they can audit process improvements within their own facilities. But they cannot, on their own, build curbside collection networks, formalize waste picker cooperatives, or guarantee the institutional stability that large-scale material recirculation demands. The result is a circular economy with a missing middle: sophisticated eco-design at one end, and a patchwork of informal recovery at the other, without the codified, quality-assured reverse logistics infrastructure that connects the two.

That infrastructure deficit has technical consequences, not merely administrative ones. Without reliable collection streams, recovered plastics arrive contaminated and heterogeneous, raising processing costs and lowering the quality of recyclate. Without codification of material specifications across the chain, downstream buyers cannot verify whether recycled content meets food-contact or performance standards. The study shows that these transactional failures are exactly what Global Value Chain theory predicts when capability gaps meet weak institutional coordination. Circular economy initiatives that focus exclusively on firm-level innovation, the authors warn, will keep colliding with these structural limits, because circularity is not a property of individual companies but of interconnected arrangements spanning technical, organizational, and institutional dimensions.

The comparative context sharpens the lesson. Prior studies of plastic packaging in Europe, Italy, Taiwan, and the United States have documented how mature extended producer responsibility schemes, standardized collection, and formal reverse logistics enable higher recirculation rates. In the Global South, by contrast, research has emphasized the pivotal role of informal recycling sectors and the co-creation of circular economy research agendas attentive to local conditions. Costa and Scur’s Brazil case bridges these literatures by showing precisely where the value chain severs: not at the design table, where focal firms have made genuine progress, but in the recovery and recirculation segments where network coordination and public capacity are essential. The pathway analysis thus offers a diagnostic template that can be applied to other Global South economies where similar informal-institutional configurations prevail.

For policymakers, the implications are concrete. Strengthening network-dependent pathways will require more than awareness campaigns or voluntary commitments. It demands investment in collection infrastructure, mechanisms to formalize and support waste picker cooperatives, codification of recyclate specifications that industry can transact upon, and regulatory enforcement that gives reverse logistics obligations teeth. For firms, the study suggests that design and process upgrading should be coupled with deliberate network-building, such as co-investment in sorting facilities and quality systems, since unilateral firm-level circularity cannot close loops that span the entire chain. For researchers, the work demonstrates the analytical value of marrying Global Value Chain governance concepts with Global Production Network perspectives that capture state and civil society actors alongside firms.

The research, supported by the São Paulo Research Foundation and the Coordination for the Improvement of Higher Education Personnel in Brazil, ultimately reframes the debate about plastics in the Global South. The question is not whether companies want to go circular, but whether the governance conditions exist to let circular materials, information, and value flow across a fragmented chain. In Brazil’s plastic packaging industry, the answer is a qualified yes at the level of the firm and a resounding not yet at the level of the network. Closing that gap, the study concludes, will require treating circularity as a collective achievement built on shared institutions, rather than a badge that individual firms can earn alone.

Subject of Research: How governance structures and institutional conditions shape circular economy upgrading pathways in the Brazilian plastic packaging value chain.

Article Title: Governance and upgrading in plastic packaging in the Global South: evidence from Brazil

Article References: Costa, L., & Scur, G. (2026). Governance and upgrading in plastic packaging in the Global South: evidence from Brazil. Journal of Industrial Ecology. https://doi.org/10.1007/s44498-026-00162-5

Image Credits: AI Generated

DOI: 10.1007/s44498-026-00162-5

Keywords: circular economy, plastic packaging, global value chains, governance, Brazil, Global South, circular upgrading, recycling, reverse logistics, informal waste sector, industrial ecology, sustainability