Another look at climate sensitivity

摘要: We revisit a recent claim that the Earth's climate system is characterized by sensitive dependence to param- eters; in particular, exhibits an asymmetric, large-amplitude response normally distributed feedback forcing. Such would imply irreducible uncer- tainty change predictions and thus have notable implications for science climate-related policy making. show equilibrium sensitivity all generality does not support such intrinsic indetermi- nacy; latter appears only essentially linear systems. The main flaw analysis led this in- appropriate linearization of intrinsically nonlinear model; there no room physical interpretations or con- clusions based on mathematical error. Sensitive depen- dence nonetheless exist system, as well models - albeit very different sense from one claimed work under scrutiny we illustrate it using classical energy balance model (EBM) with feedbacks. EBMs exhibit two saddle-node bi- furcations, more recently called "tipping points," which give rise three distinct steady-state climates, are stable. bistable behavior is, furthermore, supported results realistic, nonequilibrium models. In truly setting, indeterminacy size observed vicinity tipping points. show, fact, small disturbances cannot result response, unless at near point. discuss briefly how distance furcation may be related strength ice-albedo feedback.