This planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside of the safe operating space for humanity.
The planetary boundaries framework (1, 2) draws upon Earth system science (3). It identifies nine processes that are critical for maintaining the stability and resilience of Earth system as a whole. All are presently heavily perturbed by human activities. The framework aims to delineate and quantify levels of anthropogenic perturbation that, if respected, would allow Earth to remain in a “Holocene-like” interglacial state. In such a state, global environmental functions and life-support systems remain similar to those experienced over the past ~10,000 years rather than changing into a state without analog in human history. This Holocene period, which began with the end of the last ice age and during which agriculture and modern civilizations evolved, was characterized by relatively stable and warm planetary conditions. Human activities have now brought Earth outside of the Holocene’s window of environmental variability, giving rise to the proposed Anthropocene epoch.