The planetary boundaries approach focuses on the biophysical processes of the Earth System that determine the self-regulating capacity of the planet. It incorporates the role of thresholds related to large-scale Earth System processes, the crossing of which may trigger non-linear changes in the functioning of the Earth System, thereby challenging social–ecological resilience at regional to global scales. Together, the set of boundaries represents the dynamic biophysical “space” of the Earth System within which humanity has evolved and thrived. Source: Planetary Boundaries: Exploring the Safe Operating Space for Humanity (Rockström et al., 2009) [https://www.ecologyandsociety.org/vol14/iss2/art32/]