Early Pleistocene obliquity-scale pCO₂ variability at ~1.5 million years ago.

ABSTRACT: In the early Pleistocene, global temperature cycles predominantly varied with ~41-kyr (obliquity-scale) periodicity. Atmospheric greenhouse gas concentrations likely played a role in these climate cycles; marine sediments provide an indirect geochemical means to estimate early Pleistocene CO₂. Here we present a boron isotope-based record of continuous high-resolution surface ocean pH and inferred atmospheric CO₂ changes. Our results show that, within a window of time in the early Pleistocene (1.38-1.54 Ma), pCO₂ varied with obliquity, confirming that, analogous to late Pleistocene conditions, the carbon cycle and climate covaried at ~1.5 Ma. Pairing the reconstructed early Pleistocene pCO₂ amplitude (92 ±13 μatm) with a comparably smaller global

SUBMITTER: Dyez KA 

PROVIDER: S-EPMC7380090 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature