The ‘flickering switch’ of late Pleistocene climate change revisited

Extremely rapid fluctuations observed in records of electrical conductivity measurements (ECM) from Greenland ice-cores provoked the idea that the climate system may be capable of flickering between two states during rapid climate transitions. Here it is shown that in general, the flickers seen in ECM records probably reflect the highly non-linear response of electrical conductivity as ice approaches acid/base neutrality, rather than significant changes in the climate system. High frequency, relatively low amplitude changes in chemistry, superimposed upon the broader changes typical of climate transitions would be capable of producing the observed characteristics of ECM records. It must be stated that this result does not detract from the observation of extremely rapid changes in, for example, ice core chemistry and isotopes, which clearly demonstrate that Earth's climate is capable of very rapid and major reorganisations