In this fascinating paper, the authors provided improvements and updated the scientific basis for the planetary boundary framework {1}. This new way of thinking of the carrying capacity of the Earth attempts at defining a safe operating space for human societies based on our evolving understanding of global ecological thresholds and the resilience of the Earth system. The aim is to provide a framework allowing human populations to develop and thrive in a sustainable way, maintaining the Earth in a Holocene-like condition. Planetary boundaries have been set for several main processes, including climate change, stratospheric ozone depletion, ocean acidification, biosphere integrity, biogeochemical flows, land-system change, and freshwater use. Here, a step forward is also introduced by setting sub-global boundaries for most processes, since this could help in understanding how regional transgressions of boundaries could scale up, affecting global patterns. Although further refinements are certainly needed and boundaries for some processes, such as atmospheric aerosol loading and novel entities (i.e. introduction of non-natural compounds, modified organisms, etc.), are lacking, this represents one of the most original and visionary paradigms for the sustainable use of natural resources at a global scale. Some major limits of the approach still remain, as it does not yet account for either the regional distribution of impacts and their historical patterns, or the potential interactions among different processes. The planet, in this vision, well deserves the name Earth, deriving from our terrestrial biology. The possibility that global warming might alter the great oceanic conveyor belt, determining a climatic catastrophe, is not even considered {2}. However, the true great challenge will consist of implementing globally shared environmental policies for sustainable development.