Introduction

This report examines the planetary boundary for novel entities—human-created substances such as synthetic chemicals, plastics, and engineered materials that may disrupt Earth system processes. The authors argue that the boundary has been exceeded, as the rate of production and release of novel entities now surpasses society’s ability to assess, monitor, and manage their risks. Chemical pollution and plastic contamination are highlighted as major threats to both ecosystems and human health, capable of altering essential Earth system processes.

The planetary boundary for novel entities

The concept of planetary boundaries defines limits within which humanity can operate safely. For novel entities, no quantitative boundary has been set, but evidence shows that production and emissions have increased dramatically—chemical production has grown fiftyfold since 1950 and is expected to triple again by 2050. Material extraction for these entities was around 92 billion tonnes in 2017, projected to reach 190 billion tonnes by 2060.

The report notes that plastics exemplify the problem. Global plastic production rose 79% from 2000 to 2015 and is projected to triple by 2050. These materials have become ubiquitous, affecting biodiversity through physical and toxic impacts, such as entanglement and ingestion, and contributing to climate change through fossil-fuel-based production. The complexity and persistence of such substances mean their accumulation in the environment presents systemic risks.

An impact pathway and criteria for a control variable

To define and operationalise the boundary, the authors propose using control variables—measurable indicators that capture human-driven changes to the Earth system. They suggest an impact pathway linking resource extraction, production, release, and environmental effects. Control variables must meet three criteria: feasibility (ability to measure), relevance (link to Earth system effects), and comprehensiveness (ability to reflect the scale of impacts).

Control variables for the planetary boundary of novel entities

Several potential control variables are explored.

• Production Volumes: Chemical and plastic production volumes are proposed as feasible control variables since data are available, though often not public. Rising production highlights the “lock-in” effect, where economic and political systems maintain chemical output despite environmental imperatives. The report argues that current production growth is not within the safe operating space.
• Safety Assessment Coverage: Only a fraction of chemicals in use have undergone safety or risk assessment. For example, under the EU REACH regulation, about 23,000 substances were registered by 2020, yet roughly 80% of non-intermediate chemicals remain unassessed. This demonstrates limited global capacity for chemical evaluation and regulation.
• Emissions And Releases: Emissions of hazardous chemicals and plastics are increasing, with millions of tonnes released annually. About 2.4% of all plastics produced are estimated to enter the environment, two-thirds as macroplastics and one-third as microplastics. These pollutants have been detected in remote regions, including the deep ocean and Arctic, showing global dispersion and persistence.
• Impacts On Earth System Processes: Novel entities contribute to toxicity pressures on ecosystems. A European study found that 15 chemical compounds accounted for nearly 99.5% of cumulative ecotoxicity pressure in freshwater systems. Plastic pollution also disturbs biosphere integrity through both physical and toxic effects, with evidence of microplastic ingestion across marine species.

Discussion and conclusions

The report concludes that humanity is operating outside the safe boundary for novel entities. The increasing diversity, volume, and release of chemicals and plastics outpace the world’s capacity for risk assessment and regulatory control. As a result, planetary burdens are rising, with contamination now found in even the most remote locations.

The authors argue that the boundary is exceeded when production and emissions outstrip the global ability to monitor and assess safety. Even stabilising or reducing production may not immediately restore safety, as the persistence of many substances ensures long-term effects.

The report recommends urgent, precautionary measures to curb production and releases, similar to emission caps in climate policy. Suggested actions include enhancing circularity in product supply chains, redesigning materials for safe reuse and recycling, and transitioning to sustainable chemical design. The authors also advocate for global cooperation, equitable regulation, and the establishment of an international science-policy body to oversee chemical and waste governance.

In summary, the evidence shows that novel entities—particularly plastics and synthetic chemicals—have breached Earth’s safe operating space. Without swift, coordinated global action to reduce their production, use, and release, these substances will continue to pose significant and enduring risks to the stability of the Earth system.