Abstract
Most climate proxies of sea surface temperatures suffer from severe limitations when applied to cold temperatures that characterize Arctic environments. These limitations prevent us from constraining uncertainties for some of the most sensitive climate tipping points that can trigger rapid and dramatic global climate change such as Arctic/Polar Amplification, the disruption of the Atlantic Meridional Overturning Circulation, sea ice loss, and permafrost melting. Here, we present an approach to reconstructing sea surface temperatures globally using paired Mg/Ca - δ18Oc recorded in tests of the polar to subpolar planktonic foraminifera Neogloboquadrina pachyderma. We show that the fidelity of Mg/Ca-based paleoclimate reconstructions is compromised by variations in seawater carbonate chemistry which can be successfully quantified and isolated from paleotemperature reconstructions using a multiproxy approach. By applying the calibration to the last glacial maximum, we show that marine polar amplification has been underestimated by up to 3.0 ± 1.0 °C in model-based estimates.
| Original language | English |
|---|---|
| Article number | 9002 |
| Pages (from-to) | 1-12 |
| Number of pages | 12 |
| Journal | Nature Communications |
| Volume | 15 |
| Issue number | 1 |
| Early online date | 18 Oct 2024 |
| DOIs | |
| Publication status | Published (in print/issue) - 18 Oct 2024 |
Bibliographical note
© 2024. The Author(s).Data Access Statement
All new data and recalculated datasets shown here are available in the Supplementary Information/Source Data file. Source data are provided in this paper.Funding
This research was funded by MSCA-IF Project ARCTICO [838529], the Marine Institute of Ireland Research Programme 2014-2020 (PDOC/19/05/02), and Science Foundation Ireland Frontiers for the Future Project 21/FFP-P/10261, awarded to A.M. In addition, A.M. acknowledges Grant in Aid funding from the Marine Institute for research expedition CE20009 on the RV Celtic Explorer with special thanks to the crew sailing under Master Anthony Hobin and Research Assistant Aedin McAlear for the analysis of Ocean ALK and DIC samples from the CE20009 survey. M.R. acknowledges DFG (German Research Foundation) for funding through research grant no. RA 2068/4-1. R.C. acknowledges funding for Project CE2COAST, funded by ANR (FR), BELSPO (BE), FCT (PT), IZM (LV), MI (IE), MIUR (IT), Rannis (IS) and RCN (NO) through the 2019 “Joint Transnational Call on Next Generation Climate Science in Europe for Oceans” initiated by JPI Climate and JPI Oceans.
