Abstract

Variations in Total Solar Irradiance (TSI) have long been hypothesized to influence global mean surface temperature (GMST) on centennial to millennial timescales, but empirical evidence for this relationship has remained elusive. Focusing on the pre-industrial Holocene, when anthropogenic influences were minimal, we apply Convergent Cross Mapping (CCM), a causal-inference method, to explore the link between solar variability and climate. We analyze four combinations, pairing two temperature targets (a global mean surface reconstruction and a central-Greenland site record (GISP2)) with two TSI reconstructions, across a broad range of timescale configurations. Our results indicate that TSI had a discernible impact on temperature variability for about 80% of parameter choices, with stronger, but less consistently significant evidence of influence on GISP2 and consistently significant, but weaker evidence regarding the global mean. This contrast suggests that although solar forcing was not the dominant driver of Holocene climate fluctuations at the global scale, its influence is still detectable and may provide a useful benchmark for evaluating whether models correctly capture the nonlinear dynamics of Earth’s climate.

Date

2025

Authors

Jordan P Landers, Julien Emile-Geay, Alexander K James, Stephan B Munch, Deborah Khider, Edouard Bard

Journal

Authorea Preprints

Publisher

Authorea