Late Pleistocene δ¹¹B based carbon dioxide levels from ODP Site 154-926 ...

• Main Authors: Brown, Rachel Mary, Wilson, Paul A, Crocker, Anya J, Thomas, Chalk
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: boron isotopes; CO2; Late Miocene; Trilobatus sacculifer; Event label; Date/Time of event; Latitude of event; Longitude of event; Sample code/label; DEPTH, sediment/rock; Depth, composite; AGE; Cibicides wuellerstorfi, δ18O; Cibicides wuellerstorfi, δ13C; Globigerinoides ruber, Magnesium/Calcium ratio; Globigerinoides ruber, Boron/Calcium ratio; Globigerinoides ruber, Aluminium/Calcium ratio; Sea surface temperature; Sea surface temperature, uncertainty; Globigerinoides ruber, δ11B; Globigerinoides ruber, δ11B, uncertainty; Salinity; Salinity, uncertainty; δ11B, seawater, reconstructed; δ11B, seawater, reconstructed, uncertainty; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, uncertainty; δ11B, aqueous; Boron, total, seawater; Boron, seawater, logarithmic base dissociation constant; Ion product of water; Henry's law constant; Carbonic acid, dissociation constant; pH; Carbon dioxide, partial pressure; Relative change in pH; Climate forcing from carbon dioxide; Comment; Drilling/drill rig; Inductively coupled plasma - mass spectrometry ICP-MS; Calculated according to Lear et al. 2015; Multi-collector inductively coupled plasma mass spectrometer MC-ICP-MS; Calculated, see references; Reconstructed; Fractionation from Klochko et al. 2006; Calculated with seacarb package in R; Calculated from δ¹¹B, see reference; Calculated according to Hain et al. 2018; Smoothed ΔFCO₂; Leg154; Carbonic acid; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.946154; https://doi.pangaea.de/10.1594/PANGAEA.946154

Earth's climate cooled markedly during the Late Miocene from 12 to 5 million years ago, with far-reaching consequences for global ecosystems. However, the driving forces of these changes remain controversial. A major obstacle to progress is the uncertainty over the role played by greenhouse gas radiative forcing. Here we present boron isotope compositions for planktonic foraminifera, which record carbon dioxide change for the interval of most rapid cooling, the Late Miocene Cooling event between 7 and 5 Ma. Our record suggests that CO₂ declined by some 100 ppm over this two-million year-long interval to a minimum at approximately 5.9 Ma. Having accounted non-CO₂ greenhouse gasses and slow climate feedbacks, we estimate global mean surface temperature change for a doubling of CO₂ - Equilibrium Climate Sensitivity - to be 3.9˚C (1.8–6.7 ˚C at 95% confidence) based on comparison of our record of radiative forcing from CO₂ with a record of global mean surface temperature change. We conclude that changes in CO₂ ...