Paleoclimate Heresy

If you want to know the future, look at the past - Albert Einstein


The stochastic nature of ice-age climate variations

by John Reid

Antarctic ice core proxy temperature variations are compared with insolation values at 60 o N for the last 500 kyr. Linear regression shows that the insolation accounts for less than 10 percent of the variance of the temperature. The temperature exhibits a power law variance spectrum with an index of -2 implying that variations are the outcome of an integrating process such as a random walk. Significant peaks occur at obliquity and precession frequencies but not at the eccentricity frequency, below which there is a significant low frequency trough or cut-off. Comparison of the GISP2 10Be flux with GISP2 temperature variations suggest that different mechanisms underlie Dansgaard-Oeschger events, the Younger Dryas and Termination I. A model of ice age climate variations is proposed whereby the climate alternates between two metastable states.

Posted: 4 January 2018



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