Earth System Boundaries

June 2, 2023

Seven of eight earth system boundaries (ESBs) that are critical for stability of the planet’s health and survival of species have already been crossed, a new research paper by the Earth Commission published in Nature journal said recently, suggesting that the very future of humanity may now be at risk from the climate crisis.
About ESBs
- ESBs are scientifically quantified safe and just limits for climate, freshwater, biodiversity and different kinds of pollution.
- By operating within these limits, we can maintain a stable and resilient planet with accessibility to necessary resources.
- These are hard limits and even temporary overshooting of some of the boundaries can permanently damage the planet’s critical systems.
The seven ESBs that have been crossed are:
- climate (two local exposure boundaries— wet bulb temperatures of over 35 °C for at least 1 day of the year and extent of low-elevation coastal zones),
- functional integrity,
- and levels of surface water,
- groundwater,
- nitrogen,
- phosphorus and
- aerosols.
The eighth, which has not been crossed, is under two heads.
- In climate, 5 degree C warming is still “safe” but not ”just.”
  - “Safe and just” was crossed at 1 degree C.
- The global annual mean interhemispheric aerosol optical depth (AOD) difference, a proxy for degree of air pollution globally has also not been crossed.
India, along with other parts of South Asia, Europe, parts of Africa is a ESB transgression hotspot with the Himalayan foothills experiencing at least 5 ESB transgressions.