Kärngränserna

Kärngränserna, often translated as "planetary boundaries," is a scientific framework that identifies and quantifies environmental limits to human development within a stable Earth system. Developed by Johan Rockström and colleagues at the Stockholm Resilience Centre, this concept proposes that nine critical Earth system processes have thresholds beyond which there is a risk of abrupt or irreversible environmental change at continental or global scales.

The nine boundaries are climate change, biosphere integrity (both functional and genetic), land-system change, freshwater change, biogeochemical flows (phosphorus and nitrogen cycles), ocean acidification, atmospheric aerosol loading, stratospheric ozone depletion, and novel entities (chemicals, materials, and other human-introduced substances). For each boundary, a quantifiable target or "safe operating space" has been proposed.

Exceeding these boundaries increases the risk of pushing the Earth system into a new state, potentially rendering it less hospitable for human societies. The framework aims to provide a scientific basis for sustainable development by highlighting areas where human activities are placing unacceptable pressure on the planet's life support systems. Current scientific assessments indicate that several of these boundaries, including climate change, biosphere integrity, land-system change, and biogeochemical flows, have already been crossed. The concept of kärngränserna serves as a crucial tool for understanding global environmental risks and guiding policy decisions towards a sustainable future.