100-kyr climate cycles caused by 2.4-Myr eccentricity-modulated carbon cycles
Earth's climate has been dominated by ~100-kyr glacial cycles over the past ~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 ~21-kyr and ~100-kyr power ratios, but no significant relationship between ~41-kyr and ~100-kyr power ratios. This suggests that ~100-kyr climate cycles are more related to eccentricity-modulated precession than to obliquity. Phase analyses of benthic δ<sup>18</sup>O/ice volume and δ<sup>13</sup>C (carbon cycle) since Antarctic glaciation onset (~34 Ma) show that strong ~100-kyr cycles emerged only when these proxies were phase-coupled. Such coupling recurred at ~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 ~21-kyr/~100-kyr anticorrelation because eccentricity modulates precession amplitude. We propose that internal carbon cycle dynamics and ~2.4-Myr eccentricity-modulated δ¹⁸O/ice volume-δ¹³C coupling amplified ~100-kyr climate cycles not only over the past ~800 ka but since 34 Ma. Given that eccentricity will remain low for the next 400 kyr, ~100-kyr periodicities may continue to dominate future climate variability, assuming Earth remains in a bipolar regime.
Authors
- Chengshan Wang (ORCID: https://orcid.org/0000-0002-7403-0582)
- Benjamin Sames (ORCID: https://orcid.org/0000-0002-1123-1766)
- Hai Cheng (ORCID: https://orcid.org/0000-0002-5305-9458)
- Yongjian Huang (ORCID: https://orcid.org/0000-0001-6628-0664)
- Q. Liu (ORCID: https://orcid.org/0009-0005-4526-8574)
- Hanfei Yang (ORCID: https://orcid.org/0000-0002-2458-4544)
- Qiuzhen Yin (ORCID: https://orcid.org/0000-0002-7189-8335)
- Michael Wagreich (ORCID: https://orcid.org/0000-0002-8828-0857)
- Eun Young Lee
- Chao Ma (ORCID: https://orcid.org/0000-0002-0122-5696)
- Tiantian Wang (ORCID: https://orcid.org/0000-0002-2308-5989)
- Zhifeng Zhang (ORCID: https://orcid.org/0000-0002-7764-8740)
Institutions
- University of Vienna (AT)
- Ministry of Natural Resources (CN)
- China Geological Survey (CN)
- China University of Geosciences (Beijing) (CN)
- Chengdu University of Technology (CN)
- Guangzhou University (CN)
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (CN)
- Xi'an Jiaotong University (CN)
- UCLouvain (BE)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-08-28
- DOI
- https://doi.org/10.1038/s41467-025-63403-4
- Primary Topic
- Geology and Paleoclimatology Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Österreichischen Akademie der Wissenschaften
- China University of Geosciences, Beijing
- China Postdoctoral Science Foundation
- Petrobras
- China Scholarship Council
- China University of Geosciences
- National Key Research and Development Program of China
- Fundamental Research Funds for the Central Universities