Ecological apocalypse can also be a source of hope

Swedish Royal Academy of Sciences, Stockholm

Ecosystems world wide can shift from one configuration to another, a transition often referred to as regime shifts. Regime shifts are critical to society because they can affect the benefits people get from nature. They are also relevant for scientist and managers because they are difficult to anticipate and reverse. Examples of regime shifts include forest to savannas, coral dominated to algae dominated reefs, or the collapse of the Greenland ice sheet. While scientists have largely investigated individual regime shifts, a critical question that remains unanswered: how could regime shifts be interconnected? Whether the occurrence of one can increase the likelihood of another, or whether the occurrence of two different regime shifts is only the result of sharing the same causes.

These questions are addressed in Rocha’s talk. He reduces regime shifts to a network representation that summarizes their main drivers and processes underlying their dynamics. By combining networks of regime shift couples, cascading effects were identified. Such effects can occur in as much as 45% of all pairwise combinations of regime shifts analyzed.

The risk of cascading effects suggests that more attention should be paid to the systemic risk of the Earth’s ecosystems. Future research needs to account for the conditions under which plausible can become probable. Consequently, data collection efforts and methods development should account for potential interdependence of regime shifts. Likewise, current management and governance practices underestimate the potential risk of cascading regime shifts, more attention should be paid on management strategies that acknowledge regime shift interdependence.