Just planetary boundaries, foundations, transformation and the law

Our local to global biophysical systems (climate change, biodiversity loss) face crises and basic needs to fulfil human rights remain unmet. Yet our economic, political and legal systems keep externalizing socio-environmental issues. Hence, we ask: How can the continuous externalization of socio-environmental impacts at global to local level be addressed by building on existing legal concepts? Building on literature, the concept of Earth System Justice and legal precedents, we conclude that: (a) safe planetary boundaries are needed to protect the planetary commons in the public interest with states holding them in public trust. (b) Just boundaries require the application of the no significant harm principle of customary international law to planetary systems. This demands stringent due diligence that unlocks structural lock-ins rather than merely undertaking administrative activities. (c) Just boundaries reduce the available ecospace, a portion of which must be reserved to meet basic needs to fulfil human rights. The remaining ecospace must be shared equitably in line with Earth System Justice. (d) These findings contest the values of the dominant economic and governance system because they require more hierarchical global principes, pointing toward legal reforms in the direction of a global constitution.