  When complex systems are driven to extinction by some external factor, their
non-stationary dynamics can present an intermittent behaviour between relative
tranquility and burst of activity whose consequences are often catastrophic. To
understand and ultimately be able to predict such dynamics, we propose an
underlying mechanism based on sharp thresholds of a local generalized energy
density that naturally leads to negative feedback. We find a transition from a
continuous regime to an intermittent one, in which avalanches can be predicted
despite the stochastic nature of the process. This model may have applications
in many natural and social complex systems where a rapid depletion of resources
or generalized energy drives the dynamics. In particular, we show how this
model accurately describes the time evolution and avalanches present in a real
social system.
