Precession-induced millennial climate cycles in greenhouse Cretaceous.

ABSTRACT: Millennial-scale climate cycles persist throughout greenhouse climates, yet the mechanisms remain unclear. Here, using proxy reconstructions, we present centennial-resolution geological records from early Campanian greenhouse deposits in both mid-latitude East Asia and low-latitude Southern Atlantic. These records document pronounced millennial ( ~ 1-6 kyr) wet-dry climate cycles. The amplitude modulation relationship between the most prominent ~4-5-kyr cycles (corresponding to the ¼ precession cycle) and eccentricity aligns perfectly with the theoretically calculated equatorial insolation cycles, demonstrating the climate effect of this predicted insolation forcing on global climate. Other millennial cycles primarily emerge from these ~4-5-kyr cycles via nonlinear amplitude modulation and

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC12660683 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature