Anticipating Critical Transitions

The authors define a “tipping point” in terms of “a catastrophic bifurcation, where a minor trigger can invoke a self-propagating shift to a contrasting state.” Such “critical transitions” appear in nature and society but remain difficult to predict. The authors propose that complex systems with feature high connectivity and high homogeneity are particularly vulnerable to critical transitions, whereas those with lower connectivity and higher diversity tend to experience more gradual change. Early warning signals of an impending tipping point include “critical slowing down,” in which the system takes more and more time to recover from each successive perturbation, and “flickering,” when the system shifts rapidly back and forth between equilibria.