The Atlantic Ocean Circulation, in particular its zonally averaged component called the Atlantic Meridional Overturning Circulation (AMOC), is one of the tipping elements in the climate system. The AMOC is sensitive to freshwater perturbations and may undergo a transition to a climate disrupting state within a few decades under continuing greenhouse gas emissions. In this presentation, Prof. Dijkstra will focus on the complex systems aspects of the problem of assessing the probability of a collapse of the AMOC under future climate change.