100-kyr climate cycles caused by 2.4-Myr eccentricity-modulated carbon cycles
Zhang, Z.; Huang, Y.; Ma, C.; Yin, Q.; Yang, H.; Lee, E.Y.; CHENG, H.; Sames, B.; Wagreich, M.; Wang, T.; Liu, Q.; Wang, C. (2025). 100-kyr climate cycles caused by 2.4-Myr eccentricity-modulated carbon cycles. Nature Comm. 16(1): 8043. https://dx.doi.org/10.1038/s41467-025-63403-4
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Author keywords |
ice-sheet;frequency-modulation;persistent influence;glacial cycles;late miocene;obliquity;insolation;variability;precession;ocean |
| Authors | | Top |
- Zhang, Z.
- Huang, Y.
- Ma, C.
- Yin, Q., more
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- Yang, H.
- Lee, E.Y.
- CHENG, H.
- Sames, B.
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- Wagreich, M.
- Wang, T.
- Liu, Q.
- Wang, C.
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| Abstract |
Earth's climate has been dominated by similar to 100-kyr glacial cycles over the past similar to 800 ka, yet the mechanism remains debated. Here, we present correlation analyses of spectral power ratios of global records spanning the past 2.7 Ma, revealing a persistent anticorrelation between similar to 21-kyr and similar to 100-kyr power ratios, but no significant relationship between similar to 41-kyr and similar to 100-kyr power ratios. This suggests that similar to 100-kyr climate cycles are more related to eccentricity-modulated precession than to obliquity. Phase analyses of benthic delta O-18/ice volume and delta C-13 (carbon cycle) since Antarctic glaciation onset (similar to 34 Ma) show that strong similar to 100-kyr cycles emerged only when these proxies were phase-coupled. Such coupling recurred at similar to 2.4-Myr eccentricity maxima during the unipolar regime (before 7.5 Ma) and minima during the bipolar regime (after 4 Ma), explaining the persistent similar to 21-kyr/similar to 100-kyr anticorrelation because eccentricity modulates precession amplitude. We propose that internal carbon cycle dynamics and similar to 2.4-Myr eccentricity-modulated delta O-18/ice volume-delta C-13 coupling amplified similar to 100-kyr climate cycles not only over the past similar to 800 ka but since 34 Ma. Given that eccentricity will remain low for the next 400 kyr, similar to 100-kyr periodicities may continue to dominate future climate variability, assuming Earth remains in a bipolar regime. |
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