What is resilience ?

There is no consensus on what resilience really means. One of the objectives of the summer school is to present a diversity of views on what "reslience" means in environmental science - and how to model it.

To give a taste, here are some definitions of resilience :

"Resilience as applied to ecosystems, or to integrated systems of people and natural resources, has three defining characteristics : The amount of change the system can undergo and still retain the same controls on function and structure (still be in the same state - within the same domain of attraction) ; The degree to which the system is capable of self-organization ; The ability to build and increase the capacity for learning and adaptation." (CS Holling and Brian Walker)

"[Resilience is] the capacity of the Earth system to persist in a Holocene-like state under changing conditions by regulating biogeochemical flows (e.g., the terrestrial and marine biological carbon sinks) or by providing the capacity for ecosystems to tolerate perturbations and shocks and to continue functioning under changing abiotic conditions" (Steffen et al 2015)

"Resilience : The capacity of social, economic, and environmental systems to cope with a hazardous event or trend or disturbance, responding or reorganizing in ways that maintain their essential function, identity, and structure, while also maintaining the capacity for adaptation, learning, and transformation." (IPCC Working Group 2, Assessment Report 5, Summary for Policy Makers, 2014).

"Resilience : Flexibility of social-ecological systems to adjust to unforeseen shocks and stresses and to sustain their fundamental function, structure, identity, and feedbacks as a result of recovery or reorganization in a new context." (Chapin et al 2011)

"Resilience means embracing change and transformation over time" (Marten Scheffer 2011)

"Resilience : The speed at which a given ecosystem returns to its original state after a disturbance and the degree to which the ecosystem is capable of self-organization. More generally, when applied to ecosystem services, it is the speed at which a given ecosystem returns to a state with a similar level of functioning (even though species composition may have changed). Care needs to be applied because "resilience" has also been used to refer to what is defined as "resistance".

Resistance : The extent to which a given (eco)system keeps its original state during an external disturbance. In the case of an unstable system, this measure of ability can be seen through time as persistence." (Bohan et al 2013)