A Theory of Abrupt Climate Changes: Their Genesis and Anatomy

We combine our ice-sheet and climate models to formulate a deductive theory of abrupt changes pertaining Heinrich/Dansgaard–Oeschger (H/DO) cycles the last deglaciation punctuated by Younger Dryas (YD). Since they are all accompanied ice-rafted debris, we posit their common origin in calving ice sheet due thermal switch at its bed, which naturally endows abruptness these signals millennial timescale characteristics ice-mass balance. To distinguish H/DO cycles, differentiate triggers geothermal-heat/surface-melt inland/coastal ice, provide respective freshwater sources. surface-melt requires post-H warmth during glacial, but is already operative Holocene, DO encased within H cycle self-sustaining Holocene. They otherwise share same time signature, thus resolving this seeming puzzle commonality without invoking unknown forcing. The transcend produce observed sequence, calving-induced flux needs be boosted rerouting continental meltwater cause YD. discern key process an eddying ocean adjustment toward maximum entropy production (MEP), would melt H-induced sea warming followed gradual cooling that anchors form hierarchical Bond cycle. modelled anatomies resemble ones, may robust unified account changes.