Anna S von der Heydt , Peter Ashwin, Charles D. Camp, Michel Crucifix, Henk A Dijkstra, Peter Ditlevsen, Timothy M Lenton

This paper is currently in review for Global and Planetary Change. \\ The spectral view of variability is a compelling and adaptable tool for understanding variability of the climate. In the Mitchell (1976) seminal paper, it was used to express, on one graph with log scales, a very wide range of climate variations from millions of years to days. The spectral approach is particularly useful for suggesting causal links between forcing variability and climate response variability. However, (quasi-)periodic processes are also a natural part of the Earth system and a substantial degree of variability is intrinsic and responds to external forcing in a complex manner. There has been an enormous amount of work on understanding climate variability over the last decades. Hence in this paper, we address the question: Can we (after 40 years) update the Mitchell (1976) diagram in an essential way and provide it with a better interpretation? By reviewing both the extended observations available for such a diagram and new methodological developments in the study of the interaction between natural and forcing periodicity over a wide range of timescales, we give a positive answer to this question. In addition, we review alternative approaches to the spectral decomposition as in Mitchell and pose some challenges for a more detailed quantification of climate variability.