biostudies-literatureUnknown16(1)Mejia LMAccurate predictions of the future climate response to CO₂ depend on the ability of climate models to simulate past analog warmer climates, like the Miocene. However, one key unresolved issue in paleoclimate modeling is reproducing the pronounced high-latitude warmth and relatively flat latitudinal temperature gradients inferred from proxy records. Here, we use clumped isotope thermometry-a method that sidesteps limitations of conventional proxies-on pure coccolith calcite from a high-latitude North Atlantic site, extending from the Mid Miocene to the Quaternary. Coccolith-derived clumped isotope temperatures are on average ~9°C lower than alkenone estimates, representing the first proxy dataset to align with Miocene model outputs and calling into question the prevailing paradigNature communications10981https://www.ebi.ac.uk/biostudies/studies/S-EPMC12689775biostudies-literatureCoccolith clumped isotopes reveal modest rather than extreme northern high latitude amplification during the Miocene.PMC12689775Jaggi MStoll HMejia LMPerez-Huerta AZhang HBernasconi SMTaylor VEFernandez AGuitian JfalseCoccolith clumped isotopes reveal modest rather than extreme northern high latitude amplification during the Miocene.Accurate predictions of the future climate response to CO₂ depend on the ability of climate models to simulate past analog warmer climates, like the Miocene. However, one key unresolved issue in paleoclimate modeling is reproducing the pronounced high-latitude warmth and relatively flat latitudinal temperature gradients inferred from proxy records. Here, we use clumped isotope thermometry-a method that sidesteps limitations of conventional proxies-on pure coccolith calcite from a high-latitude North Atlantic site, extending from the Mid Miocene to the Quaternary. Coccolith-derived clumped isotope temperatures are on average ~9°C lower than alkenone estimates, representing the first proxy dataset to align with Miocene model outputs and calling into question the prevailing paradig2025-01-01T00:00:00Z2025 Dec2026-06-05T23:47:28.029Z2026-05-23T03:13:52.661ZS-EPMC126897754136586710.1038/s41467-025-65954-y