• European Marine Science
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Much of our understanding of Earth's past climate states comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, major intervals in those records that lack the temporal resolution and/or age control required to identify climate forcing and feedback mechanisms. Here we document 66 million years of global climate by a new high-fidelity Cenozoic global reference benthic carbon and oxygen isotope dataset (CENOGRID). Using recurrence analysis, we find that on timescales of millions of years Earth's climate can be grouped into Hothouse, Warmhouse, Coolhouse and Icehouse states separated by transitions related to changing greenhouse gas levels and the growth of polar ice sheets. Each Cenozoic climate state is paced by orbital cycles, but the response to radiative forcing is state dependent.

The data file `CENOGRID_Loess_20.txt` contains the astronomically tuned deep-sea benthic foraminifer carbon (������C) and oxygen (�������O) isotope reference records uniformly covering the entire Cenozoic. The first column is the tuned age in Ma, the second column the ������C, and the third column the �������O record. The original calculations were performed using the CRP Toolbox for MATLAB. In order to avoid installing the toolbox and for better performance, the functions for calculating RP and RQA were here reimplemented, providing identical result. To reproduce the RPs in Fig. 2, use the script `perform_rp.m`, for reproducing the determinism values and upper confidence bounds, use the script `perform_rqa.m`. {"references": ["T. Westerhold, N. Marwan, et al: An astronomically dated record of Earth's climate and its predictability over the last 66 million years, Science, 369(6509), 1383\u20131387 (2020)"]}

Much of our understanding of Earth's past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories. Four climate states-Hothouse, Warmhouse, Coolhouse, Icehouse-are identified on the basis of their distinctive response to astronomical forcing depending on greenhouse gas concentrations and polar ice sheet volume. Statistical analysis of the nonlinear behavior encoded in our record reveals the key role that polar ice volume plays in the predictability of Cenozoic climate dynamics.