Proxy reconstructions from marine sediment cores indicate peak temperatures in the first half of the last and current interglacial periods (the thermal maxima of the Holocene epoch, 10,000 to 6,000 years ago, and the last interglacial period, 128,000 to 123,000 years ago) that arguably exceed modern warmth1,2,3. By contrast, climate models simulate monotonic warming throughout both periods4,5,6,7. This substantial model–data discrepancy undermines confidence in both proxy reconstructions and climate models, and inhibits a mechanistic understanding of recent climate change. Here we show that previous global reconstructions of temperature in the Holocene1,2,3 and the last interglacial period8 reflect the evolution of seasonal, rather than annual, temperatures and we develop a method of transforming them to mean annual temperatures. We further demonstrate that global mean annual sea surface temperatures have been steadily increasing since the start of the Holocene (about 12,000 years ago), first in response to retreating ice sheets (12 to 6.5 thousand years ago), and then as a result of rising greenhouse gas concentrations (0.25 ± 0.21 degrees Celsius over the past 6,500 years or so). However, mean annual temperatures during the last interglacial period were stable and warmer than estimates of temperatures during the Holocene, and we attribute this to the near-constant greenhouse gas levels and the reduced extent of ice sheets. We therefore argue that the climate of the Holocene differed from that of the last interglacial period in two ways: first, larger remnant glacial ice sheets acted to cool the early Holocene, and second, rising greenhouse gas levels in the late Holocene warmed the planet. Furthermore, our reconstructions demonstrate that the modern global temperature has exceeded annual levels over the past 12,000 years and probably approaches the warmth of the last interglacial period (128,000 to 115,000 years ago).
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The datasets generated and compiled for this study are available in the NOAA Database, World Data Service for Paleoclimatology at https://www.ncdc.noaa.gov/paleo/study/31752. International Comprehensive Ocean-Atmosphere Data Set data were provided by the National Oceanic and Atmospheric Administration/Oceanic and Atmospheric Research/Earth System Research Laboratories Physical Sciences Laboratory at https://psl.noaa.gov/. Source data are provided with this paper.
A MATLAB code that implements the SAT method is available on GitHub (https://github.com/sambova/SAT).
Kaufman, D. et al. Holocene global mean surface temperature, a multi-method reconstruction approach. Sci. Data 7, 201 (2020).
Kaufman, D. et al. A global database of Holocene paleotemperature records. Sci. Data 7, 183 (2020).
Marcott, S. A., Shakun, J. D., Clark, P. U. & Mix, A. C. A reconstruction of regional and global temperature for the past 11,300 years. Science 339, 1198–1201 (2013).
Liu, Z. et al. The Holocene temperature conundrum. Proc. Natl Acad. Sci. USA 111, E3501–E3505 (2014).
Brierley, C. M. et al. Large-scale features and evaluation of the PMIP4-CMIP6 mid-Holocene simulations. Clim. Past Discuss. 2020, 1–35 (2020).
Varma, V., Prange, M. & Schulz, M. Transient simulations of the present and the last interglacial climate using the Community Climate System Model version 3: effects of orbital acceleration. Geosci. Model Dev. 9, 3859–3873 (2016).
Lu, Z., Liu, Z., Chen, G. & Guan, J. Prominent precession band variance in ENSO intensity over the last 300,000 years. Geophys. Res. Lett. 46, 9786–9795 (2019).
Hoffman, J. S., Clark, P. U., Parnell, A. C. & He, F. Regional and global sea-surface temperatures during the last interglaciation. Science 355, 276–279 (2017).
Mann, M. E. et al. Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Proc. Natl Acad. Sci. USA 105, 13252–13257 (2008).
PAGES 2k Consortium. Consistent multidecadal variability in global temperature reconstructions and simulations over the Common Era. Nat. Geosci. 12, 643–649 (2019).
Marsicek, J., Shuman, B. N., Bartlein, P. J., Shafer, S. L. & Brewer, S. Reconciling divergent trends and millennial variations in Holocene temperatures. Nature 554, 92–96 (2018).
Rodriguez, L. G. et al. Mid-Holocene, coral-based sea surface temperatures in the western tropical Atlantic. Paleoceanogr. Paleoclimatol. 34, 1234–1245 (2019).
Timmermann, A., Sachs, J. & Timm, O. E. Assessing divergent SST behavior during the last 21 ka derived from alkenones and G. ruber-Mg/Ca in the equatorial Pacific. Paleoceanogr. Paleoclimatol. 29, 680–696 (2014).
Leduc, G., Schneider, R., Kim, J.-H. & Lohmann, G. Holocene and Eemian sea surface temperature trends as revealed by alkenone and Mg/Ca paleothermometry. Quat. Sci. Rev. 29, 989–1004 (2010).
Liu, Y. et al. A possible role of dust in resolving the Holocene temperature conundrum. Sci. Rep. 8, 4434 (2018).
Park, H.-S., Kim, S.-J., Stewart, A. L., Son, S.-W. & Seo, K.-H. Mid-Holocene Northern Hemisphere warming driven by Arctic amplification. Sci. Adv. 5, eaax8203 (2019).
Affolter, S. et al. Central Europe temperature constrained by speleothem fluid inclusion water isotopes over the past 14,000 years. Sci. Adv. 5, eaav3809 (2019).
Martin, C. et al. Early Holocene Thermal Maximum recorded by branched tetraethers and pollen in Western Europe (Massif Central, France). Quat. Sci. Rev. 228, (2020).
Longo, W. M. et al. Insolation and greenhouse gases drove Holocene winter and spring warming in Arctic Alaska. Quat. Sci. Rev. 242, 106438 (2020).
Köhler, P., Nehrbass-Ahles, C., Schmitt, J., Stocker, T. F. & Fischer, H. A. 156 kyr smoothed history of the atmospheric greenhouse gases CO2, CH4, and N2O and their radiative forcing. Earth Syst. Sci. Data 9, 363–387 (2017).
Huybers, P. & Eisenman, I. (eds) NOAA/NCDC Paleoclimatology Program, http://eisenman.ucsd.edu/code/daily_insolation.m (IGBP PAGES/World Data Center for Paleoclimatology, 2006).
Berger, A. Long-term variations of daily insolation and Quaternary climatic changes. J. Atmos. Sci. 35, 2362–2367 (1978).
Freeman, E. et al. ICOADS Release 3.0: a major update to the historical marine climate record. Int. J. Climatol. 37, 2211–2232 (2017).
Be, A. & Hamilton, W. H. Ecology of recent planktonic foraminifera. Micropaleontology 13, 87–106 (1967).
De Deckker, P. The Indo-Pacific warm pool: critical to world oceanography and world climate. Geosci. Lett. 3, 20 (2016).
Moffa-Sanchez, P., Rosenthal, Y., Babila, T. L., Mohtadi, M. & Zhang, X. Temperature evolution of the Indo-Pacific warm pool over the Holocene and the last deglaciation. Paleoceanogr. Paleoclimatol. 34, 1107–1123 (2019).
Ruddiman, W., He, F., Vavrus, S. & Kutzbach, J. The early anthropogenic hypothesis: a review. Quat. Sci. Rev. 240, 106386 (2020).
Studer, A. S. et al. Increased nutrient supply to the Southern Ocean during the Holocene and its implications for the pre-industrial atmospheric CO2 rise. Nat. Geosci. 11, 756–760 (2018).
Cowtan, K. & Way, R. G. Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends. Q. J. R. Meteorol. Soc. 140, 1935–1944 (2014).
Pausata, F. S. R. et al. The greening of the Sahara: past changes and future implications. One Earth 2, 235–250 (2020).
Ritchie, J. C., Cwynar, L. C. & Spear, R. W. Evidence from north-west Canada for an early Holocene Milankovitch thermal maximum. Nature 305, 126–128 (1983).
McKay, N. P., Kaufman, D. S., Routson, C. C., Erb, M. P. & Zander, P. D. The onset and rate of Holocene neoglacial cooling in the Arctic. Geophys. Res. Lett. 45, 12487–12496 (2018).
Hays, J. D., Imbrie, J. & Shackleton, N. J. Variations in the Earth’s orbit: pacemaker of the Ice Ages. Science 194, 1121–1132 (1976).
Milankovitch, M. Kanon Der Erdbestrahlung Und Seine Anwendung Auf Das Eiszeitenproblem (Mihaila Ćurčića, 1941).
Imbrie, J. et al. On the structure and origin of major glaciation cycles. 1. Linear responses to Milankovitch forcing. Paleoceanogr. Paleoclimatol. 7, 701–738 (1992).
Wang, P. X. et al. The global monsoon across time scales: mechanisms and outstanding issues. Earth Sci. Rev. 174, 84–121 (2017).
Clark, P. U. et al. Oceanic forcing of penultimate deglacial and last interglacial sea-level rise. Nature 577, 660–664 (2020).
Lambeck, K., Rouby, H., Purcell, A., Sun, Y. & Sambridge, M. Sea level and global ice volumes from the Last Glacial Maximum to the Holocene. Proc. Natl Acad. Sci. USA 111, 15296–15303 (2014).
Grant, K. M. et al. Rapid coupling between ice volume and polar temperature over the past 150,000 years. Nature 491, 744–747 (2012).
Reimer, P. J. et al. Intcal13 and Marine13 radiocarbon age calibration curves 0-50,000 years cal BP. Radiocarbon 55, 1869–1887 (2013).
Rafter, P. A., Herguera, J.-C. & Southon, J. R. Extreme lowering of deglacial seawater radiocarbon recorded by both epifaunal and infaunal benthic foraminifera in a wood-dated sediment core. Clim. Past 14, 1977–1989 (2018).
Galbraith, E. D., Kwon, E. Y., Bianchi, D., Hain, M. P. & Sarmiento, J. L. The impact of atmospheric pCO2 on carbon isotope ratios of the atmosphere and ocean. Glob. Biogeochem. Cycles 29, 307–324 (2015).
Haslett, J. & Parnell, A. A simple monotone process with application to radiocarbon-dated depth chronologies. J. R. Stat. Soc. C 57, 399–418 (2008).
Lisiecki, L. E. & Raymo, M. E. A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanogr. Paleoclimatol. 20, https://doi.org/10.1029/2004PA001071 (2005).
Shackleton, N. J., Hall, M. A. & Vincent, E. Phase relationships between millennial‐scale events 64,000–24,000 years ago. Paleoceanogr. Paleoclimatol. 15, 565–569 (2000).
Rosenthal, Y., Boyle, E. A. & Slowey, N. Temperature control on the incorporation of magnesium, strontium, fluorine, and cadmium into benthic foraminiferal shells from Little Bahama Bank: prospects for thermocline paleoceanography. Geochim. Cosmochim. Acta 61, (1997).
Rosenthal, Y., Field, M. P. & Sherrell, R. M. Precise determination of element/calcium ratios in calcareous samples using sector field inductively coupled plasma mass spectrometry. Anal. Chem. 71, 3248–3253 (1999).
Rosenthal, Y., Holbourn, A. E., Kulhanek, D. K. & Expedition 363 Scientists. Western Pacific Warm Pool. In Proc. IODP Vol. 363, https://doi.org/10.14379/iodp.proc.363.2018 (International Ocean Discovery Program, 2018).
Minoshima, K., Kawahata, H. & Ikehara, K. Changes in biological production in the mixed water region (MWR) of the northwestern North Pacific during the last 27 kyr. Palaeogeogr. Palaeoclimatol. Palaeoecol. 254, 430–447 (2007).
Bard, E. et al. Retreat velocity of the North Atlantic polar front during the last deglaciation determined by 14C accelerator mass spectrometry. Nature 328, 791–794 (1987).
Bard, E., Rostek, F., Turon, J.-L. & Gendreau, S. Hydrological impact of Heinrich events in the subtropical northeast Atlantic. Science 289, 1321–1324 (2000).
Martrat, B. et al. Four climate cycles of recurring deep and surface water destabilizations on the Iberian margin. Science 317, 502–507 (2007).
Rodrigo-Gámiz, M., Martínez-Ruiz, F., Rampen, S. W., Schouten, S. & Sinninghe Damsté, J. S. Sea surface temperature variations in the western Mediterranean Sea over the last 20 kyr: a dual-organic proxy (UK′37 and LDI) approach. Paleoceanogr. Paleoclimatol. 29, 87–98 (2014).
Cacho, I. et al. Dansgaard-Oeschger and Heinrich event imprints in Alboran Sea paleotemperatures. Paleoceanogr. Paleoclimatol. 14, 698–705 (1999).
Isono, D. et al. The 1500-year climate oscillation in the midlatitude North Pacific during the Holocene. Geology 37, 591–594 (2009).
Yamamoto, M., Yamamuro, M. & Tanaka, Y. The California current system during the last 136,000 years: response of the North Pacific High to precessional forcing. Quat. Sci. Rev. 26, 405–414 (2007).
Herbert, T. D. et al. Collapse of the California Current during glacial maxima linked to climate change on land. Science 293, 71–76 (2001).
Ziegler, M., Nürnberg, D., Karas, C., Tiedemann, R. & Lourens, L. J. Persistent summer expansion of the Atlantic Warm Pool during glacial abrupt cold events. Nat. Geosci. 1, 601–605 (2008).
Schmidt, M. W., Weinlein, W. A., Marcantonio, F. & Lynch-Stieglitz, J. Solar forcing of Florida Straits surface salinity during the early Holocene. Paleoceanogr. Paleoclimatol. 27, https://doi.org/10.1029/2012PA002284 (2012).
Zhao, M., Beveridge, N. A. S., Shackleton, N. J., Sarnthein, M. & Eglinton, G. Molecular stratigraphy of cores off northwest Africa: sea surface temperature history over the last 80 Ka. Paleoceanogr. Paleoclimatol. 10, 661–675 (1995).
Schmidt, M. W., Spero, H. J. & Lea, D. W. Links between salinity variation in the Caribbean and North Atlantic thermohaline circulation. Nature 428, 160–163 (2004).
Schmidt, M. W. et al. Impact of abrupt deglacial climate change on tropical Atlantic subsurface temperatures. Proc. Natl Acad. Sci. USA 109, 14348–14352 (2012).
Lea, D. W., Pak, D. K., Peterson, L. C. & Hughen, K. A. Synchroneity of tropical and high-latitude Atlantic tmperatures over the Last Glacial Termination. Science 301, 1361–1364 (2003).
de Garidel-Thoron, T., Beaufort, L., Linsley, B. K. & Dannenmann, S. Millennial-scale dynamics of the east Asian winter monsoon during the last 200,000 years. Paleoceanogr. Paleoclimatol. 16, 491–502 (2001).
Rosenthal, Y., Oppo, D. W. & Linsley, B. K. The amplitude and phasing of climate change during the last deglaciation in the Sulu Sea, western equatorial Pacific. Geophys. Res. Lett. 30, https://doi.org/10.1029/2002GL016612 (2003).
Zhao, M., Huang, C.-Y., Wang, C.-C. & Wei, G. A millennial-scale U37K′ sea-surface temperature record from the South China Sea (8°N) over the last 150 kyr: monsoon and sea-level influence. Palaeogeogr. Palaeoclimatol. Palaeoecol. 236, 39–55 (2006).
Pelejero, C., Grimalt, J. O., Heilig, S., Kienast, M. & Wang, L. High-resolution UK37 temperature reconstructions in the South China Sea over the past 220 kyr. Paleoceanogr. Paleoclimatol. 14, 224–231 (1999).
Benway, H. M., Mix, A. C., Haley, B. A. & Klinkhammer, G. P. Eastern Pacific Warm Pool paleosalinity and climate variability: 0–30 kyr. Paleoceanogr. Paleoclimatol. 21, https://doi.org/10.1029/2005PA001208 (2006).
Dubois, N., Kienast, M., Normandeau, C. & Herbert, T. D. Eastern equatorial Pacific cold tongue during the Last Glacial Maximum as seen from alkenone paleothermometry. Paleoceanogr. Paleoclimatol. 24, https://doi.org/10.1029/2009PA001781 (2009).
Bolliet, T. et al. Mindanao Dome variability over the last 160 kyr: episodic glacial cooling of the West Pacific Warm Pool. Paleoceanogr. Paleoclimatol. 26, https://doi.org/10.1029/2010PA001966 (2011).
Kienast, M., Steinke, S., Stattegger, K. & Calvert, S. E. Synchronous tropical South China Sea SST change and Greenland warming during deglaciation. Science 291, 2132–2134 (2001).
Fan, W. et al. Variability of the Indonesian throughflow in the Makassar Strait over the last 30 ka. Sci. Rep. 8, 5678 (2018).
Weldeab, S., Lea, D. W., Schneider, R. R. & Andersen, N. 155,000 years of west African monsoon and ocean thermal evolution. Science 316, 1303–1307 (2007).
Weldeab, S., Schneider, R. R., Kölling, M. & Wefer, G. Holocene African droughts relate to eastern equatorial Atlantic cooling. Geology 33, 981–984 (2005).
Lea, D. W., Pak, D. K. & Spero, H. J. Climate impact of Late Quaternary equatorial Pacific sea surface temperature variations. Science 289, 1719–1724 (2000).
Lea, D. W. et al. Paleoclimate history of Galápagos surface waters over the last 135,000yr. Quat. Sci. Rev. 25, 1152–1167 (2006).
Pena, L. D., Cacho, I., Ferretti, P. & Hall, M. A. El Niño–Southern Oscillation–like variability during glacial terminations and interlatitudinal teleconnections. Paleoceanogr. Paleoclimatol. 23, https://doi.org/10.1029/2008PA001620 (2008).
Schröder, J. F., Holbourn, A., Kuhnt, W. & Küssner, K. Variations in sea surface hydrology in the southern Makassar Strait over the past 26 kyr. Quat. Sci. Rev. 154, 143–156 (2016).
Linsley, B. K., Rosenthal, Y. & Oppo, D. W. Holocene evolution of the Indonesian throughflow and the western Pacific Warm Pool. Nat. Geosci. 3, 578–583 (2010).
Bova, S. C. et al. Links between eastern equatorial Pacific stratification and atmospheric CO2 rise during the last deglaciation. Paleoceanogr. Paleoclimatol. 30, 1407–1424 (2015).
Arz, H. W., Pätzold, J. & Wefer, G. Correlated millennial-scale changes in surface hydrography and terrigenous sediment yield inferred from last-glacial marine deposits off northeastern Brazil. Quat. Res. 50, 157–166 (1998).
Weldeab, S., Schneider, R. R. & Kölling, M. Deglacial sea surface temperature and salinity increase in the western tropical Atlantic in synchrony with high latitude climate instabilities. Earth Planet. Sci. Lett. 241, 699–706 (2006).
Visser, K., Thunell, R. & Stott, L. Magnitude and timing of temperature change in the Indo-Pacific warm pool during deglaciation. Nature 421, 152–155 (2003).
Lückge, A. et al. Monsoon versus ocean circulation controls on paleoenvironmental conditions off southern Sumatra during the past 300,000 years. Paleoceanogr. Paleoclimatol. 24, https://doi.org/10.1029/2008PA001627 (2009).
Gibbons, F. T. et al. Deglacial δ18O and hydrologic variability in the tropical Pacific and Indian oceans. Earth Planet. Sci. Lett. 387, 240–251 (2014).
Xu, J., Holbourn, A., Kuhnt, W., Jian, Z. & Kawamura, H. Changes in the thermocline structure of the Indonesian outflow during Terminations I and II. Earth Planet. Sci. Lett. 273, 152–162 (2008).
Lawrence, K. T. & Herbert, T. D. Late Quaternary sea-surface temperatures in the western Coral Sea: implications for the growth of the Australian Great Barrier Reef. Geology 33, 677–680 (2005).
Lopes dos Santos, R. A. et al. Abrupt vegetation change after the Late Quaternary megafaunal extinction in southeastern Australia. Nat. Geosci. 6, 627–631 (2013).
Lopes dos Santos, R. A. et al. Comparison of organic (UK´37, TEXH86, LDI) and faunal proxies (foraminiferal assemblages) for reconstruction of late Quaternary sea surface temperature variability from offshore southeastern Australia. Paleoceanogr. Paleoclimatol. 28, 377–387 (2013).
Pahnke, K. & Sachs, J. P. Sea surface temperatures of southern midlatitudes 0–160 kyr B.P. Paleoceanogr. Paleoclimatol. 21, https://doi.org/10.1029/2005PA001191 (2006).
Anand, P., Elderfield, H. & Conte, M. H. Calibration of Mg/Ca thermometry in planktonic foraminifera from a sediment trap time series. Paleoceanogr. Paleoclimatol. 18, https://doi.org/10.1029/2002PA000846 (2003).
Tierney, J. E., Malevich, S. B., Gray, W., Vetter, L. & Thirumalai, K. Bayesian calibration of the Mg/Ca paleothermometer in planktic foraminifera. Paleoceanogr. Paleoclimatol. 34, 2005–2030 (2019).
Gray, W. R. & Evans, D. Nonthermal influences on Mg/Ca in planktonic foraminifera: a review of culture studies and application to the Last Glacial Maximum. Paleoceanogr. Paleoclimatol. 34, 306–315 (2019).
Prahl, F. G., Muehlhausen, L. A. & Zahnle, D. L. Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions. Geochim. Cosmochim. Acta 52, 2303–2310 (1988).
Tierney, J. E. & Tingley, M. P. BAYSPLINE: a new calibration for the alkenone paleothermometer. Paleoceanogr. Paleoclimatol. 33, 281–301 (2018).
Schneider, T. Analysis of incomplete climate data: estimation of mean values and covariance matrices and imputation of missing values. J. Clim. 14, 853–871 (2001).
Yeager, S. G., Shields, C. A., Large, W. G. & Hack, J. J. The low-resolution CCSM3. J. Clim. 19, 2545–2566 (2006).
Timmermann, A., Lorenz, S. J., An, S.-I., Clement, A. & Xie, S.-P. The effect of orbital forcing on the mean climate and variability of the tropical Pacific. J. Clim. 20, 4147–4159 (2007).
Delcroix, T. et al. Sea surface temperature and salinity seasonal changes in the western Solomon and Bismarck seas. J. Geophys. Res. Oceans 119, 2642–2657 (2014).
Palmer, M. R. & Pearson, P. N. A. 23,000-year record of surface water pH and pCO2 in the western equatorial Pacific Ocean. Science 300, 480–482 (2003).
Sikes, E. L., O’Leary, T., Nodder, S. D. & Volkman, J. K. Alkenone temperature records and biomarker flux at the subtropical front on the Chatham Rise, SW Pacific Ocean. Deep Sea Res. Part I 52, 721–748 (2005).
King, A. L. & Howard, W. Planktonic foraminiferal δ13C records from Southern Ocean sediment traps: new estimates of the oceanic Suess Effect. Glob. Biogeochem. Cycles 18, GB2007 (2004).
Park, E. M. Variations In GDGT Flux And TEX Thermometry In Three Distinct Oceanic Regimes Of The Atlantic Ocean: A Sediment Trap Study. https://epic.awi.de/id/eprint/51148/1/EPark_PhDThesis_2019.pdf PhD thesis, University of Bremen (2019).
Amante, C. & Eakins, B. W. ETOPO1 Global Relief Model Converted To PanMap Layer Format. https://doi.org/10.1594/PANGAEA.769615 (NOAA-National Geophysical Data Center, PANGAEA, 2009).
Emile-Geay, J., McKay, N. P., Wang, J. & Anchukaitis, K. J. CommonClimate/PAGES2k_phase2 code: first public release https://doi.org/10.5281/zenodo.545815 (2017).
This research used samples and data provided by the International Ocean Discovery Program (IODP). We thank the science party, technical staff and crew of IODP Expedition 363, who together ensured the successful recovery of IODP Site U1485. Funding for this research was provided by NSF grants OCE-1834208 and OCE-1810681, the NSF-sponsored US Science Support Program for IODP, the Institute of Earth, Ocean, and Atmospheric Sciences at Rutgers University, the Chinese NSF (grant NSFC41630527), Chinese MOST (grant 2017YFA0603801), the School of Geography, Nanjing Normal University and the USIEF-Fulbright Program.
The authors declare no competing interests.
Peer review information Nature thanks Jeroen Groeneveld, Jennifer Hertzberg, Feng Zhu, and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Extended data figures and tables
a, Reservoir age estimates calculated by measuring co-occurring wood and G. ruber 14C ages and subtracting the wood 14C age from planktic foraminifer 14C age. Twelve reservoir age estimates were deemed outliers (see Methods) and are not shown. Shading represents 2σ error estimate. b, Final age model for the upper 27.5 m CCSF-A of Site U1485 constructed using the Bchron age modelling software package for R43. Sedimentation across the Holocene is approximately constant at a rate of 62 cm kyr−1. Shading represents the 3σ error estimate. The red square indicates an outlying 14C date that is not included in the final age model.
Benthic foraminiferal δ18O record from Site U1485 (blue) measured on Cibicidoides pachyderma (>212 μm) plotted with the LR04 benthic stack (black)44 and the benthic foraminifer δ18O record from Site MD95-2042 from the Iberian Margin (purple)45. Dashed lines show tie points used to define age control for the LIG and Termination II section of Site U1485. Depth scale for Site U1485 is CCSF-A. Foraminiferal δ18O for Site U1485 and MD95-2042 are reported relative to the Pee Dee belemnite (PDB) standard.
Application of the SAT method to Mg/Ca SSTSN from Site U1485 (a–d) and October SSTs from the CCSM3 accelerated model simulation (e–h)7. MASST is estimated by regressing seasonal SSTs with insolation averaged over a range of window lengths, from 30 to 270 days, with the same central 30-day interval. Widening the window length changes the slope of the regression between insolation and seasonal SST (d, h) but has a negligible impact on the SAT calculated MASST anomalies. Shaded region in b reflects the 2 s.e. uncertainty.
a, Map of SST records used in this study showing proxy type and whether the site has a LIG section. See Extended Data Table 1 for a list of records and their citations. b, c, Temporal availability of records over the Holocene and LIG intervals, respectively. Figure constructed using MATLAB and code from Emile-Geay et al.105.
Extended Data Fig. 8 Application of SAT method to model seasonal SSTs from core locations in the Eastern Equatorial Pacific (EEP), Southern Hemisphere extratropics, Northern Hemisphere extratropics, and tropical Atlantic.
a–d, Proxy SSTSN anomalies plotted with SSTSN output from the nearest grid cell in the CCSM3 accelerated model simulation. e–h, SAT method MASST (blue) calculated from model SSTSN data shown in a–d plotted with the actual model MASST data (black) for each location. All SST anomalies in this figure are calculated relative to values averaged between 115 ka and 116 ka.
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Bova, S., Rosenthal, Y., Liu, Z. et al. Seasonal origin of the thermal maxima at the Holocene and the last interglacial. Nature 589, 548–553 (2021). https://doi.org/10.1038/s41586-020-03155-x
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