A paper published today in Science finds "the climate system can be highly nonlinear, meaning that small changes in one part can lead to much larger changes elsewhere."

"Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change."

"When the climates of the more local high-latitude Pacific and Atlantic sectors varied in parallel, large, abrupt climate fluctuations occurred on a more global scale."

One of many examples would be the interactions of the Pacific Decadal Oscillation [PDO] and the Atlantic Multidecadal Oscillation [AMO], which are sometimes aligned in the same positive phase to produce abrupt global warming, sometimes aligned in the same negative phase to produce abrupt global cooling, and sometimes in opposite phases which "cancel" their net global effect.





Systems which are "highly nonlinear" and chaotic are extremely difficult to impossible to predict or model. The projections of current climate models show that the models really boil down to just a simplistic 1:1 linear function of CO2 levels:



