Outside the Safe Operating Space of the Planetary Boundary for Novel Entities

Abstract

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.

Keywords: Earth system impacts; cap on emissions; chemical pollution; chemicals management capacity; plastic pollution; unknown planetary boundary threats.

Figure 1

A generalized impact pathway for novel entities connecting production capacity, environmental release, fate, and distribution to perturbation of Earth system processes.

Figure 2

Current rising global trends of chemical industry production, expressed as the relative growth in some novel entities between 2000 and 2017 (for when comparable data are available): 1. Global production capacity for the chemical industry as a whole, plastics production and pesticide active ingredients (for which earliest data are from 2008); 2. Per capita production capacity in weight for key monomers and solvents: benzene, butadiene, ethylene, propylene, toluene, and xylene, 3: Global consumption of antibiotics. Data from the Global Chemicals Outlook II, Geyer et al. 2017, and Søgaard Jørgensen et al.