Paleolatitudinal gradient of carbon dioxide content in the Serpukhovian atmosphere of the Northern Hemisphere

This study focuses on reconstructing the spatial distribution of carbon dioxide in the atmosphere (pCO2) of the Northern Hemisphere during the Early Carboniferous (Serpukhovian, ziegleri Zone) – a time marking the onset of the Late Paleozoic Ice Age. The isotopic analysis of carbonates and conodont elements are used to overcome limitations of existing paleoclimate models, which primarily operate with average pCO2 values. The obtained results indicate the presence of a paleolatitudinal gradient with a maximum in the tropical belt. The average pCO2 value is 582 ppm, comparable to the COPSE model. This work highlights the importance of considering spatial variations of carbon dioxide in paleoclimate reconstructions.