Lecture 20: Defining safe operating spaces for societies

Question 1

What do exponential curves signify?

Answer 1

Positive feedback loops (reinforcing) and a high probability of reaching a tipping point – before collapse.

Question 2

Safe limit CO2 for climate is…

Nitrogen…

Phosphorus…

Answer 2

~350 ppm

exceeds safe limit

close to safe limit

Question 3

Challenges to using planetary boundaries

Some variables affected by

Answer 3

Regional change eg. Fertilizer and biogeochemical flows) and others by global change (eg. emissions and climate warming).

Planetary limits on environmental variables means limits of human activities - too contentious?

Many of the control variables are not independent of each other - e.g. climate and land use;

Idea of ‘safe limits’ presupposes data and understanding of where the tipping points are – and when they will happen;

Global concept but impacts and decisions are made at local and regional scales.

Can we create any regional management tools?

Question 4

Manage local ecosystems to get global resilience

From global to local commons

Answer 4

Change laws, rules and management at local level – like dealing with unregulated deforestation.

Question 5

Manage local ecosystems to get global resilience

From high to low uncertainty

Answer 5

Tipping points are much easier to understand at local levels.

Question 6

Manage local ecosystems to get global resilience

From negative to positive framing

Answer 6

Gloom and predictions may back fire – instead encourage action-orientated framing of safe operating spaces.