We submit that the safe operating space of the planetary boundary of novel entities is exceeded since annual production and releases are increasing at a pace that outstrips the global capacity for assessment and monitoring. The novel entities boundary in the planetary boundaries framework refers to entities that are novel in a geological sense and that could have large-scale impacts that threaten the integrity of Earth system processes. We review the scientific literature relevant to quantifying the boundary for novel entities and highlight plastic pollution as a particular aspect of high concern. An impact pathway from production of novel entities to impacts on Earth system processes is presented. We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables. The increasing rate of production and releases of larger volumes and higher numbers of novel entities with diverse risk potentials exceed societies’ ability to conduct safety related assessments and monitoring. We recommend taking urgent action to reduce the harm associated with exceeding the boundary by reducing the production and releases of novel entities, noting that even so, the persistence of many novel entities and/or their associated effects will continue to pose a threat. 

Plastics are an international governance priority because of extensive and resource-intensive production, uncontrolled environmental releases, and failure to control the chemicals within the materials. We examine the evidence that plastics have exceeded the planetary safe operating space, discussing how plastics pollution affects multiple Earth system processes along the impact pathway from resource extraction and production to release to environmental fate and impacts. Multiple lines of evidence capture the complex reality of these novel entities; a single planetary boundary quantification would be detrimental. We demonstrate causal links between plastics and other environmental problems, exacerbating the consequences of breaching other planetary boundaries. We propose biophysically defined control variables for the planetary boundaries framework as a way to measure, monitor, and mitigate global plastics pollution. We call for urgent action, recognizing plastics pollution not only as a waste management problem but as an integrative part of climate change, biodiversity, and natural-resource-use policy.

Plastics are deeply embedded in contemporary life, causing irreversible harms across social-ecological systems. As a “novel entity” within the Planetary Boundaries framework, their chemical complexity, diversity, cross-sectoral impacts, and pushback from powerful actors reveal limits in traditional governance. Amid the Plastics Treaty negotiations, we discuss/present urgent science-policy issues through structured expert elicitation. We present the Experts Multi-Issue Knowledge Elicitation method - a flexible, co-productive approach that addresses social-ecological dimensions of plastics pollution. Involving 21 interdisciplinary experts, EMIKE identified 21 critical issues spanning toxic chemicals, inequality, climate impacts, financing and policy incoherence. It produced a matrix of interrelated indicators across the plastics life cycle to support adaptive, just, and evidence-based policymaking. Deliberations emphasized the inseparability of social-ecological issues, limits of technocratic approaches, and the need to democratize science-policy interfaces, grounded in precautionary action, transparency, and justice-based governance. EMIKE offers a transferable tool for other complex sustainability challenges requiring systems-based responses.

Negotiations for an international legally binding instrument to end plastics pollution are a highly-contested arena framing “plastics pollution” as a global policy problem. High and low-ambition groupings of political actors strive to control the problem representation, a power struggle ultimately affecting everyday people worldwide and the planetary environment.

Drawing on Plastics Treaty negotiation texts from 2022 and 2024, with participant observations of Intergovernmental Negotiating Committee sessions (INC-1 to INC-5.1), we critically interrogate evolving representations of the plastics pollution problem, combining Bacchi’s “What is the Problem Represented to be” (WPR) approach with a social-ecological systems perspective. Our approach contextualizes problem representation within understanding of sustainable systems.

A minority group of countries has dominated the INC process, representing plastics pollution as a consumer waste problem, where inadequate end-of-life management of plastic (a single undifferentiated material) affects the marine environment. These low-ambition actors, notably petro-states, exert power over the INC process through stalling, lobbying, mis- and disinformation, political pressures and even intimidation by industry actors. Left unproblematized are human rights, just transition, effects of plastics (complex assemblages of chemicals) on human health, and transboundary responsibilities of plastics producers, including on climate and biodiversity.

These issues are red line items for petro-states, while civil society groups, Indigenous people, and sustainability-concerned scientists press for their inclusion in the Plastics Treaty. By INC-5.1, most member states supported a higher-ambition treaty, yet no treaty text was agreed. Viewing problem representations as social-ecological issues shows how a narrow waste framing is unjust, exacerbating existing impacts of plastics pollution, especially on already vulnerable communities.