Human activity dangerously compromises four of the nine systems that are key to maintaining the stability of Earth, report researchers.
The study establishes planetary boundaries—thresholds beyond which there will be irreversible and abrupt environmental change. Those nine boundaries are:
- Climate change
- Change in biosphere integrity, meaning biodiversity loss and species extinction
- Land-system change, such as deforestation
- Biogeochemical flows, meaning phosphorus and nitrogen cycles
- Stratospheric ozone depletion
- Ocean acidification