Figure — Cliff diagram” of equilibrium Thermohaline Circulation (THC) in the North Atlantic Ocean overturning varying PRTP (pure rate of time preference — a part of discounting) and climate sensitivity. Two states of the system — “normal” (20 Sv of warm water flow to Northern Europe) and “collapsed” (0 Sv) THC—are seen here. The numbers are only for illustration as several parameters relevant to the conditions in which the THC collapse occurs are not varied across their full range in this calculation, which is primarily shown to illustrate the emergent property of high sensitivity to discounting in a coupled socio-natural model (e.g., from Mastrandrea and Schneider, 2002). 1 Sv is equal to one million cubic meters of water flowing per second and is the measure that is normally used to gauge the intensity of oceanic currents.