Plastics pollution exacerbates the impacts of all planetary boundaries

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.