1. Global framework of planetary limits

1.1 Spirit of the framework: preserving a reference environmental state for the Earth system

The planetary limits framework proposes to assess the impacts of human activities on a planetary scale in relation to an environmental reference that has been established on the basis of the climatic equilibrium of the Holocene, a climatic era that the Anthropocene is tending to replace by the influence of human activities on biogeophysical equilibria. Planetary limits are an assessment framework that establishes several environmental thresholds that must not be exceeded to avoid destabilizing the current climatic equilibrium of the Earth system. These limits have been challenged by the expansion of humanity on Earth since the beginning of the Holocene, just over 10,000 years ago. While some...