Therefore, efforts to decarbonize the plastic packaging economy must be intrinsically linked to strategies that reduce plastic waste. Addressing one objective in isolation, whether focusing solely on emissions reduction or waste management, risks producing unsustainable, short-lived solutions. In addition to environmental sustainability, economic sustainability is equally crucial for achieving a truly sustainable plastic packaging economy, one that accounts for evolving market demand and shifts in the broader economic landscape over time. Therefore, a holistic, integrated approach is essential to develop long-term strategies that simultaneously tackle both the climate and environmental impacts of plastic packaging in an economically sustainable manner.
Circular economy has emerged as a promising strategy for achieving decarbonization and reducing waste generation. However, building a truly sustainable circular economy for plastic packaging is a complex challenge that may require a multifaceted approach, ranging from implementing advanced end-of-life technologies to consumption reduction strategies enabled through effective policy interventions.
To advance toward a circular economy for plastic packaging, it is essential to differentiate packaging products not only by their polymer composition, but also by their shape, size, and intended application. These factors play a critical role in the end-of-life recovery of plastics, as variations in composition, size, shape and contamination level influence both the sorting technology required and the potential recycling yield. For example, small-format plastics often evade conventional sorting systems and necessitate advanced technologies for effective separation. Similarly, multi-layer plastic films pose significant challenges due to their complex, heterogeneous chemical composition. Optical sorters, typically designed for mono-material plastics, struggle to identify and separate these materials. Moreover, such films cannot be mechanically recycled and instead require more sophisticated chemical recycling processes for proper treatment. Heavily contaminated plastics are also of such problematic plastics, the recycling of which is impractical due to the high level of contamination.
In this work, we present a detailed superstructure network of technologies that spans the full spectrum from low to high technology readiness levels (TRL) for end-of-life sorting and recycling. Beyond recycling, the network also integrates key decarbonization technologies, including electrochemical processes for monomer synthesis, bio-based pathways for producing plastic recycling feedstocks, and carbon capture and utilization (CCU) systems. This holistic approach supports both material circularity and emissions reduction across the plastic value chain.
Identifying the optimal set of technologies necessitates a multi-objective optimization approach that incorporates uncertainty, enabling robust decision-making for cost-effective pathways to decarbonization and circularity. Crucially, this optimization must be situated within a dynamic, time-responsive framework that accounts for evolving socio-economic trajectories and systemic transformations in the energy grid, broader economy, and climate. Because achieving net-zero is inherently a multi-period challenge, the modeled plastic packaging system must be integrated with these broader temporal shifts to ensure realistic and robust outcomes.
Planning over multiple time horizons, typically extending to 2050, allows stakeholders to evaluate which strategies to pursue, when to invest, and the magnitude of those investments. Such an approach equips decision-makers with a forward-looking tool to balance environmental and economic goals over time. Therefore, to achieve this, we develop a dynamic stochastic multi-objective optimization framework which can also account for uncertainty under a wait-and-see approach.
Preliminary findings suggest that achieving net-zero emissions before 2050 is feasible through a strategic combination of high-tech sorting, advanced recycling technologies, carbon capture and utilization (CCU), and bio-based production pathways. However, this transition entails trade-offs, including increased supply chain costs and higher energy demands. Moreover, since recovery processes can generate microplastic waste, the integration of advanced filtration systems is essential to mitigate their environmental impact, particularly in preventing marine biodiversity loss, adding more to the economic burden of technological solutions. Initial results highlight that decarbonizing the electricity grid is essential for maximizing the environmental advantages of advanced technologies. If the grid remains carbon-intensive, the substantial energy requirements of new sorting and treatment systems may undermine their potential to lower greenhouse gas emissions. While bio-based materials offer potential, their effectiveness is limited by uncertainties surrounding carbon capture and land-use impacts, making them insufficient on their own. A more effective approach combines bio-based alternatives, advanced technologies, and clean energy, leading to significant cuts in emissions and plastic waste, albeit with increased energy use and financial investment.
In pursuing net-zero emissions for plastic packaging, it is essential to look beyond purely technological innovations and consider a broader suite of non-technological and socio-institutional circularity strategies. These approaches, often overlooked, can offer more cost-effective pathways to decarbonization while addressing critical issues of waste generation and material efficiency. For example, regulatory measures such as banning problematic plastics—particularly small-format items, multi-layer films, and conventional polymers used for food packaging (which can become heavily contaminated), that are difficult to recycle—can be instrumental. These materials can be substituted with functionally equivalent alternatives designed with recyclability or reuse in mind, thereby supporting a more circular and sustainable packaging system. By shifting focus toward such systemic interventions, it is possible to reduce the reliance on costly technological fixes and avoid trade-offs between climate goals, cost reduction, and waste minimization.