Influence of temporally varying weatherability on CO<sub>2</sub>–climate coupling and ecosystem change in the late Paleozoic

Abstract

Abstract. Earth's penultimate icehouse, the Late Paleozoic Ice Age (LPIA), was a time of dynamic glaciation and repeated ecosystem perturbation, under conditions of substantial variability in atmospheric pCO2 and O2. Improved constraints on the evolution of atmospheric pCO2 and O2 : CO2 during the LPIA and its subsequent demise to permanent greenhouse conditions is crucial for better understanding the nature of linkages between atmospheric composition, climate, and ecosystem perturbation during this time. We present a new and age-recalibrated pCO2 reconstruction for a 40-Myr interval (~313 to 273 Ma) of the late Paleozoic that (1) confirms a previously hypothesized strong CO2-glaciation linkage, (2) documents synchroneity between major pCO2 and O2 : CO2 changes and compositional turnovers in terrestrial and marine ecosystems, (3) lends support for a modeled progressive decrease in the CO2 threshold for initiation of continental ice sheets during the LPIA, and (4) indicates a likely role of CO2 and O2 : CO2 thresholds in floral ecologic turnovers. Modeling of the relative role of CO2 sinks and sources, active during the LPIA and its demise, on steady-state pCO2 using an intermediate complexity climate-C cycle model (GEOCLIM) and comparison to the new multi-proxy CO2 record provides new insight into the relative influences of the uplift of the Central Pangaean Mountains, intensifying aridification, and increasing mafic rock to-granite rock ratio of outcropping rocks on the global efficiency of CO2 consumption and secular change in steady-state pCO2 through the late Paleozoic.

Low-latitude climate change linked to high-latitude glaciation during the Late Paleozoic Ice Age: evidence from the terrigenous detrital kaolinite

“…The relationship between low-latitude kaolinite content in the study area and the high-latitude glacial cycles established 195 by previous studies is shown in Figure 9. The three higher kaolinite content intervals from S-I, S-III, and S-V are roughly isochronous with climate warming interglacial periods and are consistent with an increase of global atmospheric pCO2 (Richey et al, 2020;Fig. 9f) and high surface seawater temperatures (Korte et al, 2005;Grossman et al, 2008;Fig.…”

“…The Cisuralian (early Permian) represents the peak of the Late Paleozoic Ice Age (LPIA; ca. 332-260 Ma) in which significant shifts from glacial to interglacial conditions occurred in high-latitude Gondwana (e.g., Montañez et al, 2007;30 Fielding et al, 2008;Montañez and Poulsen, 2013;Garbelli et al, 2019;Richey et al, 2020). These glacial-interglacial events caused fluctuations in the global climate and are recorded by indirect proxies from mid-and low-latitudes in marine and continental deposits (e.g., Korte et al, 2005;Grossman et al, 2008;Davydov, 2014;Yang et al, 2016Yang et al, , 2020.…”

Reply on RC2

“…The three intervals with lower kaolinite content from S-II, S-IV, and S-VI roughly correspond to climate cooling glacial periods from glaciations P1 and P2 and the transition period to glaciation P3 in high latitudes. The intervals with lower 200 kaolinite content are also are isochronous with an interval of decreasing global atmospheric pCO2(Foster et al, 2017;Richey et al, 2020; Fig. 9f) and surface seawater temperatures(Korte et al, 2005; Fig.…”

Trends and Rhythms in Climate Change During the Early Permian Icehouse

“…(a) Refined chronostratigraphy of Asselian and Sakmarian. (b) Low‐latitude paleosol‐carbonate‐based p CO 2 record (Montañez et al., 2007; Richey et al., 2020). (c) Record on Gondwana.…”

“…Reconstructed atmospheric p CO 2 indicates a stepwise rise from a minimum across the Carboniferous–Permian boundary to maximum concentrations toward the end of the Sakmarian (Montañez et al., 2007; Richey et al., 2020). A rise in p CO 2 would not only promote the demise of the DSIII in the Karoo Basin on Gondwana but also enhance surface evaporation to desiccate the low latitudes (Figures 9d–9f).…”