Figure 8.27: Environmental Dynamics, Multiple Equilibria, and the S-Shaped EDC

Negative Feedback at the Low-Ice Equilibrium

Negative Feedback at the High-Ice Equilibrium (Virtuous Circle)

Figure 8.28: Climate Equilibria Feedback Loops

Basins of Attraction in the Environmental Dynamics Model

An environmental system's state from one year to the next is modeled by an S-shaped curve. In the middle region of this curve, the slope is very steep, meaning a small change in the system's state in one year causes a much larger change in the following year. What does this steepness imply about the system's dynamics within this specific region?

System Resilience in a High-Quality State

Explaining Persistent Ecosystem Degradation

A system's environmental quality from one year to the next is modeled by an S-shaped curve plotted against a 45-degree line (where quality is unchanged). Match each region of the S-shaped curve with its corresponding dynamic characteristic.

According to the model represented by the S-shaped Environmental Dynamics Curve, the stable, low-quality environmental state, often described as a 'vicious circle', is maintained by a positive feedback process.

Ecosystem Response to a Major Shock

Analyzing the Shape of the Environmental Dynamics Curve

An environmental system, modeled by an S-shaped curve that plots its state in one period against the next, is currently in a stable, high-quality equilibrium (e.g., extensive sea ice). Graphically, this corresponds to a point where the S-shaped curve is nearly flat and intersects a 45-degree line. Why is this equilibrium considered resilient to small, temporary negative shocks?

Coral Reef Ecosystem Shift

An ecosystem's quality is observed over several years. Initially, it is in a healthy, resilient state. Following a major negative shock, it rapidly degrades and settles into a persistently poor state. Arrange the following descriptions of the system's dynamics into the correct chronological order, starting from the initial healthy state.