This is a useful tool to understand the limits of the Earth’s sustainability. It is the Planetary Boundaries Framework from the Stockholm Resilience Centre. This helps us think in terms of risks, and to consider how the effects of breaching each boundary interact with each other.
The nine most significant boundaries that we should* avoid breaching are:
- Stratospheric ozone depletion – threshold tackled but still risky
- Biodiversity loss – boundary breached
- Chemical dispersion – boundary unquantified but seriously concerning
- Climate change – boundary breached
- Ocean acidification – boundary breached 35% above norm due to CO2 emissions
- Freshwater consumption – boundary breached
- Land system change – boundary breached
- Nitrogen and Phosphorous inputs to biosphere and oceans – Nitrogen cycle significantly breached
- Atmospheric aerosol loading – boundary not quantified
*Notice how many of these are already breached
Discuss particular boundaries – or pairs of them – in small groups. You could do some online research to be able to share what you find with the rest of the group.
As a whole group, discuss the diagram overall:
Do you think this model encompasses all the planetary boundaries or do you think there are there others?
Looking at the ones that are most seriously breached, talk about how they relate to one another.
Which areas had you been unaware of? What could you help increase public understanding about?