# Regime Shift **Entity class:** Scientific concept **Domain:** Ecology / Earth-System Science / Complex Systems **Doc Type:** Canonical Wiki Node **Maturity:** Developing **Aliases:** Critical transition ## Definition A **regime shift**, also called a **critical transition**, is an abrupt and persistent reorganization of a complex system from one stable state to another, occurring when slowly changing conditions push the system past a threshold. Because the new state is self-reinforcing, returning to the old one usually requires conditions far more favorable than those under which the shift occurred, a property called hysteresis. ## Examples Marten Scheffer and colleagues documented regime shifts in shallow lakes that flip from clear water to turbid algal dominance, coral reefs that give way to macroalgae, and savannas that become deserts. Their work on early-warning signals, such as slowing recovery from small disturbances, gave the concept a measurable footing. ## Corpus Context [[articles/There Is Only One Rocket on the Pad|There Is Only One Rocket on the Pad]] uses the concept for the point of no return: once [[wiki/Metabolic Lock-In|metabolic lock-in]] is reached, the system's new state resists reversal, and the open-biosphere regime cannot be recovered by policy adjustment. [[wiki/Marsification|Marsification]] describes the corresponding shift in habitability, and [[wiki/State-Dependent Catastrophe|state-dependent catastrophe]] describes how the same hazard strikes differently on each side of the threshold. ## Relationships - **Related concepts:** [[wiki/Phase Transition|Phase Transition]] · [[wiki/Attractor|Attractor]] · [[wiki/Dissipative Structure|Dissipative Structure]] - **Corpus applications:** [[wiki/The Bloom|The Bloom]] · [[wiki/Metabolic Lock-In|Metabolic Lock-In]] · [[wiki/Marsification|Marsification]] · [[wiki/State-Dependent Catastrophe|State-Dependent Catastrophe]] - **Historical instance:** [[wiki/Great Oxidation Event|Great Oxidation Event]] ## Sources / Provenance - Scheffer, Marten, et al. "Catastrophic Shifts in Ecosystems." *Nature* 413 (2001): 591–596. - Scheffer, Marten. *Critical Transitions in Nature and Society.* Princeton University Press, 2009. - Scheffer, Marten, et al. "Early-Warning Signals for Critical Transitions." *Nature* 461 (2009): 53–59.