Chapter 02 · Nature, land & waterBiodiversity & Nature
Earth system boundaries
Definition
Earth system boundaries are a set of quantified biophysical limits published by the Earth Commission in 2023 (Rockström, Gupta and colleagues, Nature) that extend the planetary boundaries framework by distinguishing safe boundaries — which maintain a stable, resilient Earth system — from just boundaries, which minimise significant harm to humans and other living beings. Quantified across climate, biosphere, freshwater, nutrient cycles and aerosols, the framework found seven of eight safe and just boundaries already transgressed; the just climate boundary (1.0°C) is stricter than the safe one (1.5°C).
References
primary framework paper
safe/just distinction and transgression status
Overview
What it means
A scientific floor-and-ceiling for sustainability that builds equity directly into Earth-system limits, designed for translation into targets for cities and companies.
How it is used
The boundaries inform science-based targets for nature (SBTN) and climate, and frame the "safe and just corridor" between minimum resource access and biophysical limits.
Why it matters
They are the state of the art in operationalising planetary boundaries with justice — the scientific counterpart to frameworks like the Doughnut.