Articles | Volume 14, issue 10
https://doi.org/10.5194/cp-14-1391-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-14-1391-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum
Department of Earth & Space Sciences, University of Washington,
Seattle, WA 98195, USA
Department of Marine, Earth & Atmospheric Sciences, North
Carolina State University, Raleigh, NC 27695, USA
Katharine W. Huntington
Department of Earth & Space Sciences, University of Washington,
Seattle, WA 98195, USA
Nathan D. Sheldon
Department of Earth & Environmental Sciences, University of
Michigan, Ann Arbor, MI 48104, USA
Tammo Reichgelt
Lamont Doherty Earth Observatory, Columbia University, Palisades,
NY 10964, USA
Related authors
No articles found.
Dominique K. L. L. Jenny, Tammo Reichgelt, Charlotte L. O'Brien, Xiaoqing Liu, Peter K. Bijl, Matthew Huber, and Appy Sluijs
Clim. Past, 20, 1627–1657, https://doi.org/10.5194/cp-20-1627-2024, https://doi.org/10.5194/cp-20-1627-2024, 2024
Short summary
Short summary
This study reviews the current state of knowledge regarding the Oligocene
icehouseclimate. We extend an existing marine climate proxy data compilation and present a new compilation and analysis of terrestrial plant assemblages to assess long-term climate trends and variability. Our data–climate model comparison reinforces the notion that models underestimate polar amplification of Oligocene climates, and we identify potential future research directions.
Rebekah A. Stein, Nathan D. Sheldon, Sarah E. Allen, Michael E. Smith, Rebecca M. Dzombak, and Brian R. Jicha
Clim. Past, 17, 2515–2536, https://doi.org/10.5194/cp-17-2515-2021, https://doi.org/10.5194/cp-17-2515-2021, 2021
Short summary
Short summary
Modern climate change drives us to look to the past to understand how well prior life adapted to warm periods. In the early Eocene, a warm period approximately 50 million years ago, southwestern Wyoming was covered by a giant lake. This lake and surrounding environments made for excellent preservation of ancient soils, plant fossils, and more. Using geochemical tools and plant fossils, we determine the region was a warm, wet forest and that elevated temperatures were maintained by volcanoes.
Tammo Reichgelt, William J. D'Andrea, Ailín del C. Valdivia-McCarthy, Bethany R. S. Fox, Jennifer M. Bannister, John G. Conran, William G. Lee, and Daphne E. Lee
Clim. Past, 16, 1509–1521, https://doi.org/10.5194/cp-16-1509-2020, https://doi.org/10.5194/cp-16-1509-2020, 2020
Short summary
Short summary
Carbon dioxide (CO2) levels are increasing in the atmosphere. CO2 has a direct fertilization effect on plants, meaning that plants can photosynthesize more and create more biomass under higher atmospheric CO2. This paper outlines the first direct evidence of a carbon fertilization effect on plants in Earth's past from 23 × 106 yr old fossil leaves, when CO2 was higher. This allowed the biosphere to extend into areas that are currently too dry or too cold for forests.
Christopher K. West, David R. Greenwood, Tammo Reichgelt, Alexander J. Lowe, Janelle M. Vachon, and James F. Basinger
Clim. Past, 16, 1387–1410, https://doi.org/10.5194/cp-16-1387-2020, https://doi.org/10.5194/cp-16-1387-2020, 2020
Short summary
Short summary
During the globally warm early Eocene 56 million years ago, lush forests extended up to the high Arctic. Fossil plants from the Canadian High Arctic and Pacific Northwest of North America are a window into this past
greenhouse world. We used an improved method for plant fossil climate reconstruction that provides a consensus reconstruction from all available proxies. Results show that the early Eocene climate in northern North America was similar across a broad range of latitudes.
Related subject area
Subject: Atmospheric Dynamics | Archive: Terrestrial Archives | Timescale: Cenozoic
Stable isotope evidence for long-term stability of large-scale hydroclimate in the Neogene North American Great Plains
Post-Pliocene establishment of the present monsoonal climate in SW China: evidence from the late Pliocene Longmen megaflora
Stable isotopic evidence of El Niño-like atmospheric circulation in the Pliocene western United States
Livia Manser, Tyler Kukla, and Jeremy K. C. Rugenstein
Clim. Past, 20, 1039–1065, https://doi.org/10.5194/cp-20-1039-2024, https://doi.org/10.5194/cp-20-1039-2024, 2024
Short summary
Short summary
The Great Plains host the single most important climatic boundary in North America, separating the humid east from the semi-arid west. How this boundary will move as the world warms holds implications for the societies and ecosystems of the Plains. We study how this boundary changed in the past during a period of globally warmer temperatures. We find that this climatic boundary appears to be in the same location as today, suggesting that the Great Plains climate is resilient to global changes.
T. Su, F. M. B. Jacques, R. A. Spicer, Y.-S. Liu, Y.-J. Huang, Y.-W. Xing, and Z.-K. Zhou
Clim. Past, 9, 1911–1920, https://doi.org/10.5194/cp-9-1911-2013, https://doi.org/10.5194/cp-9-1911-2013, 2013
M. J. Winnick, J. M. Welker, and C. P. Chamberlain
Clim. Past, 9, 903–912, https://doi.org/10.5194/cp-9-903-2013, https://doi.org/10.5194/cp-9-903-2013, 2013
Cited articles
Bader, N. E., Nicolaysen, K. P., Maldonado, R. L., Murray, K. E., and Mudd, A. C.: Extensive middle Miocene weathering interpreted from a well-preserved paleosol, Cricket Flat, Oregon, USA, Geoderma, 239, 195–205, 2015.
Barron, E.: Eocene equator-to-pole surface ocean temperatures: A significant climate problem?, Paleoceanography, 2, 729–739, 1987.
Brand, W. A., Assonov, S. S., and Coplen, T. B.: Correction for the 17O interference in δ13C measurements when analyzing CO2 with stable isotope mass spectrometry, Pure Appl. Chem., 82, 1719–1733, 2010.
Breecker, D. O., Sharp, Z. D., and McFadden, L. D.: Seasonal bias in the formation and stable isotopic composition of pedogenic carbonate in modern soils from central New Mexico, USA, Geol. Soc. Am. Bull., 121, 630–640, 2009.
Burgener, L., Huntington, K., Hoke, G., Schauer, A., Ringham, M., Latorre, C., and Diaz, F.: Variations in soil carbonate formation and seasonal bias over > 4 km of relief in the western Andes (30° S) revealed by clumped isotope thermometry, Earth Planet. Sc. Lett., 441, 188–199, 2016.
Cerling, T. E.: The stable isotopic composition of modern soil carbonate and its relationship to climate, Earth Planet. Sc. Lett., 71, 229–240, 1984.
Cerling, T. E. and Quade, J.: Stable carbon and oxygen isotopes in soil carbonates, Geophys. Mono., 78, 217–231, 1993.
Clyde, W. C., Sheldon, N. D., Koch, P. L., Gunnell, G. F., and Bartels, W. S.: Linking the Wasatchian/Bridgerian boundary to the Cenozoic Global Climate Optimum: new magnetostratigraphic and isotopic results from South Pass, Wyoming, Palaeogeogr. Palaeocl., 167, 175–199, 2001.
Daëron, M., Blamart, D., Peral, M., and Affek, H.: Absolute isotopic abundance ratios and the accuracy of Δ47 measurements, Chem. Geol., 442, 83–96, 2016.
Dennis, K. J., Affek, H. P., Passey, B. H., Schrag, D. P., and Eiler, J. M.: Defining and absolute reference frame for clumped isotope studies of CO2, Geochim. Cosmochim. Ac., 75, 7117–7131, 2011.
Diffenbaugh, N. S. and Field, C. B.: Changes in ecologically critical terrestrial climate conditions, Science, 341, 486–492, 2013.
Diffenbaugh, N. S., Singh, D., Mankin, J. S., Horton, D. E., Swain, D. L., Touma, D., Charland, A., Liu, Y., Haugen, M., Tsiang, M., and Rajaratnam, B.: Quantifying the influence of global warming on unprecedented extreme climate events, P. Natl. Acad. Sci. USA, 114, 4881–4886, 2017.
Driese, S. G., Peppe, D. J., Beverly, E. J., DiPietro, L. M., Arellano, L. N., and Lehmann, T.: Paleosols and paleoenvironments of the early Miocene deposits near Karunga, Lake Victoria, Kenya, Palaeogeogr. Palaeocl., 443, 167–182, 2016.
Eiler, J. M.: Clumped-isotope geochemistry – The study of naturally-occurring, multiply-substituted isotopologues, Earth Planet. Sc. Lett., 262, 309–327, 2007.
Eiler, J. M.: Paleoclimate reconstruction using carbonate clumped isotope thermometry: Quaternary Sci. Rev., 30, 3575–3588, 2011.
Eldrett, J. S., Greenwood, D. R., Polling, M., Brinkhuis, H., and Sluijs, A.: A seasonality trigger for carbon injection at the Paleocene–Eocene Thermal Maximum, Clim. Past, 10, 759–769, https://doi.org/10.5194/cp-10-759-2014, 2014.
Evans, D., Sagoo, N., Renema, W., Cotton, L. J., Muller, W., Todd, J. A., Saraswati, P. K., Stassen, P., Ziegler, M., Pearson, P. N., Valdes, P. J., and Affek, H. P.: Eocene greenhouse climate revealed by coupled clumped isotope-Mg/Ca thermometry, P. Natl. Acad. Sci. USA, 115, 1174–1179, 2018.
Fang, J., Wang, Z., and Tang, Z.: Atlas of woody plants in China: Distribution and climate, Springer-Verlag (Beijing, CH), 1909 pp., 2011.
Frantz, C. M., Petryshyn, V. A., Marenco, P. J., Tripatic, A., Berelson, W. M., and Corsetti, F. A.: Dramatic local environmental change during the Early Eocene Climatic Optimum detected using high-resolution chemical analyses of Green River stromatolites, Palaeogeogr. Palaeocl., 405, 1–15, 2014.
Gallagher, T. M. and Sheldon, N. D.: A new paleothermometer for forest paleosols and its implications for Cenozoic climate, Geology, 41, 647–650, 2013.
Gallagher, T. M. and Sheldon, N. D.: Combining soil water balance and clumped isotopes to understand the nature and timing of pedogenic carbonate formation, Chem. Geol., 435, 79–91, 2016.
Garzione, C. A., Auerbach, D. J., Smith, J. J., Rosario, J. J., Passey, B. H., Jordan, T. E., and Eiler, J. M.: Clumped isotope evidence for diachronous surface cooling of the Altiplano and pulsed surface uplift of the Central Andes, Earth Planet. Sc. Lett., 393, 173–181, 2014.
GBIF (Global Biodiversity Information Facility): Open Access Biodiversity Data, available at: http://gbif.org, last access: July 2016.
Ghosh, P., Adkins, J., Affek, H., Balta, B., Guo, W., Schauble, E., Schrag, D., and Eiler, J.: 13C-18O bonds in carbonate minerals: a new kind of paleothermometer, Geochim. Cosmochim. Ac., 70, 1439–1456, 2006.
Greenwood, D. R. and Wing, S. L.: Eocene continental climates and latitudinal temperature gradients, Geology, 23, 1044–1048, 1995.
Greenwood, D. R., Archibald, S. B., Mathewes, R. W., and Moss, P. T.: Fossil biotas from the Okanagan Highlands, southern British Columbia and northeastern Washington State: Climates and ecosystems across an Eocene landscape, Can. J. Earth Sci., 42, 167–185, 2005.
Greenwood, D. R., Keefe, R. L., Reichgelt, T., and Webb, J. A.: Eocene paleobotanical altimetry of Victoria's Eastern Uplands, Aust. J. Earth Sci., 64, 625–637, 2017.
Grimm, G. W. and Denk, T.: Reliability and resolution of the coexistence approach- A revalidation using modern day data, Rev. Palaeobot. Palyno., 172, 33–47, 2012.
Grimm, G. W. and Potts, A. J.: Fallacies and fantasies: the theoretical underpinnings of the Coexistence Approach for palaeoclimate reconstruction, Clim. Past, 12, 611–622, https://doi.org/10.5194/cp-12-611-2016, 2016.
Guo, W. and Eiler, J. M.: Temperatures of aqueous alteration and evidence for methane generation on the parent bodies of the CM chondrites, Geochim. Cosmochim. Ac., 71, 5565–5575, 2007.
Harbert, R. and Nixon, K.: Climate reconstruction analysis using coexistence likelihood estimation (CRACLE): A method for the estimation of climate using vegetation, Am. J. Bot., 102, 1277–1289, 2015.
He, B., Olack, G., and Colman, A.: Pressure baseline correction and high-precision CO2 clumped isotope (Δ47) analysis by gas-source isotope ratio mass spectrometry, J. Mass Spectrom., 44, 1318–1329, 2012.
Hickey, L.: Stratigraphy and paleobotany of the Golden Valley Formation (early Tertiary) of western North Dakota, Geol. Soc. Am. Mem., 150, 183 pp., 1977.
Hijmans, R. J., Cameron, S. E., Parra, J. L., Jones, P. G., and Jarvis, A.: Very high resolution interpolated climate surfaces for global land areas, Int. J. Climatol., 25, 1965–1978, 2005.
Hough, B. G., Fan, M., and Passey, B. H.: Calibration of the clumped isotope geothermometer in soil carbonate in Wyoming and Nebraska, USA: Implications for paleoelevation and paleoclimate reconstruction, Earth Planet. Sc. Lett., 391, 110–120, 2014.
Huber, M. and Caballero, R.: The early Eocene equable climate problem revisited, Clim. Past, 7, 603–633, https://doi.org/10.5194/cp-7-603-2011, 2011.
Huntington, K. W., Eiler, J. M., Affek, H. P., Guo, W., Bonifacie, M., Yeung, L. Y., Thiagarajan, N., Passey, B., Tripati, A., Daeron, M., and Came, R.: Methods and limitations of clumped CO2 isotope (Δ47) analysis by gas-source isotope ratio mass spectrometry, J. Mass Spectrom., 44, 1318–1329, 2009.
Hyland, E. G. and Sheldon, N. D.: Coupled CO2-climate response during the Early Eocene Climatic Optimum, Palaeogeogr. Palaeoclim., 369, 125–135, 2013.
Hyland, E. G. and Sheldon, N. D.: Examining the spatial consistency of palaeosol proxies: Implications for palaeoclimatic and palaeoenvironmental reconstructions in terrestrial sedimentary basins, Sedimentology, 63, 959–971, 2016.
Hyland, E. G., Sheldon, N. D., and Cotton, J. M.: Constraining the early Eocene climatic optimum: A terrestrial interhemispheric comparison, Geol. Soc. Am. Bull., 129, 244–252, 2017.
IPCC (Intergovernmental Panel on Climate Change): Fourth Assessment Report: Climate Change (AR4), in: IPCC (Geneva, SWI), edited by: Pachuari, R. K. and Reisinger, A., 104 pp., 2007.
IPCC (Intergovernmental Panel on Climate Change): Fifth Assessment Report: Climate Change (AR5), in: IPCC (Geneva, SWI), edited by: Pachuari, R. K. and Meyer, L.A., 151 pp., 2014.
Jagniecki, E. A., Lowenstein, T. K., Jenkins, D. M., and Demicco, R. V.: Eocene atmospheric CO2 from the nahcolite proxy, Geology, 43, 1075–1078, 2015.
Jordan, G. J.: Uncertainty in paleoclimatic reconstructions based on leaf physiognomy, Aust. J. Bot., 45, 527–547, 1997.
Kelson, J., Huntington, K. W., Schauer, A., Saenger, C., and Lechler, A.: Toward a universal carbonate clumped isotope calibration: Diverse synthesis and preparatory methods suggest a single temperature relationship, Geochim. Cosmochim. Ac., 197, 104–131, 2017.
Kluge, T., John, C., Jourdan, A., Davis, S., and Crawshaw, J.: Laboratory calibration of the calcium carbonate clumped isotope thermometer in the 25–250 °C temperature range, Geochim. Cosmochim. Ac., 157, 213–227, 2015.
Koch, P. L.: Isotopic reconstruction of past continental environments, Annu. Rev. Earth Pl. Sc., 26, 573–623, 1998.
Lunt, D. J., Dunkley Jones, T., Heinemann, M., Huber, M., LeGrande, A., Winguth, A., Loptson, C., Marotzke, J., Roberts, C. D., Tindall, J., Valdes, P., and Winguth, C.: A model-data comparison for a multi-model ensemble of early Eocene atmosphere–ocean simulations: EoMIP, Clim. Past, 8, 1717–1736, https://doi.org/10.5194/cp-8-1717-2012, 2012.
MacGinitie, H. D.: The Eocene Green River Flora of northwestern Colorado and northeastern Utah, University of California Press (Berkeley, CA), 201 pp., 1969.
Manchester, S. and Dilcher, D.: Pterocaryoid fruits in the Paleogene of North America and their evolutionary and biogeographic significance, Am. J. Bot., 69, 275–286, 1982.
Manchester, S. R.: Revisions to Roland Brown's North American Paleocene flora, Ac. Mus. Natl. Prag., 70, 153–210, 2014.
McInerney, F. A. and Wing, S. L.: The Paleocene-Eocene Thermal Maximum: A perturbation of carbon cycle, climate and biosphere with implications for the future, Annu. Rev. Earth Pl. Sc., 39, 489–516, 2011.
Michel, L. A., Peppe, D. J., Lutz, J. A., Driese, S. G., Dunsworth, H. M., Harcourt-Smith, W., Horner, W. H., Lehmann, T., Nightingale, S., and McNulty, K. P.: Remnants of an ancient forest provide ecological context for Early Miocene fossil apes, Nat. Commun., 5, 3236, https://doi.org/10.1038/ncomms4236, 2014.
Mosbrugger, V. and Utescher, T.: The coexistence approach – a method for quantitative reconstructions of tertiary terrestrial palaeoclimate data using plant fossils, Palaeogeogr. Palaeocl., 134, 61–86, 1997.
NCDC (National Climatic Data Center): United States Climate Normals, 1981–2010: Climatography of the US, National Oceanic and Atmospheric Administration, available at: https://www.ncdc.noaa.gov/data-access/land-based-station-data/land-based-datasets/climate-normals/1981-2010-normals-data (last access: April 2015), 2010.
Pal, J. S., Giorgi, F., Bi, X., Elguindi, N., Solmon, F., Gao, X., Rauscher, S. A., Francisco, R., Zakey, A., Winter, J., Ashfaq, M., Syed, F. S., Bell, J. L., Diffenbaugh, N. S., Karmacharya, J., Konare, A., Martinez, D., da Rocha, R. P., Sloan, L. C., and Steiner, A. L.: The ICTP RegCM3 and RegCNET: Regional climate modeling for the developing world, B. Am. Meteorol. Soc., 88, 1395–1409, 2007.
Passey, B. H., Levin, N., Cerling, T. E., Brown, F., and Eiler, J.: High-temperature environments of human evolution in East Africa based on bond ordering in paleosol carbonates, P. Natl. Acad. Sci. USA, 107, 11245–11249, 2010.
PCDMI (Program for Climate Model Diagnosis and Intercomparison): Bias corrected and downscaled World Climate Research Programme's Coupled Model Intercomparison Project phase 5 (CMIP5) climate projections, available at: http://gdo-dcp.ucllnl.org/downscaled_cmip_projections/ (last access: January 2016), 2014.
Peppe, D. J.: Hot summers in continental interiors: The case against equability during the early Paleogene, Geology, 41, 95–96, 2013.
Peppe, D. J., Royer, D. L., Wilf, P., and Kowalski, E.: Quantification of large uncertainties in fossil leaf paleoaltimetry, Tectonics, 29, TC3015, https://doi.org/10.1029/2009TC002549, 2010.
Peters, N., Huntington, K. W., and Hoke, G.: Hot or not? Impact of seasonally variable soil carbonate formation on paleotemperature and O-isotope records from clumped isotope thermometry, Earth Planet. Sc. Lett., 361, 208–218, 2013.
Quade, J., Eiler, J., Daeron, M., and Achyuthan, H.: The clumped isotope geothermometer in soil and paleosol carbonate, Geochim. Cosmochim. Ac., 105, 92–100, 2013.
R Core Team: R: A language and environment for statistical computing: Foundation for Statistical Computing (Vienna, AT), available at: https:/www.r-project.org (last access: December 2017), 2013.
Reichgelt, T., Kennedy, E. M., Conran, J. G., Mildenhall, D. C., and Lee, D. E.: The early Miocene paleolake Manuherikia: vegetation heterogeneity and warm-temperate to subtropical climate in southern New Zealand, J. Paleolimnol., 53, 349–365, 2015.
Retallack, G. J.: Cenozoic paleoclimate on land in North America, J. Geol., 115, 271–294, 2007.
Ringham, M. C., Hoke, G. D., Huntington, K. W., and Aranibar, J. N.: Influence of vegetation type and site-to-site variability on soil carbonate clumped isotope records, Andean piedmont of Central Argentina (32–34° S), Earth Planet. Sc. Lett., 440, 1–11, 2016.
Roe, G. H. and Baker, M. B.: Why is climate sensitivity so unpredictable?, Science, 318, 629–632, 2007.
Sarg, J. F., Suriamin, H., Tanavsuu-Milkeviciene, K., and Humphrey, J. D.: Lithofacies, stable isotopic composition, and stratigraphic evolution of microbial and associated carbonates, Green River Formation (Eocene), Am. Assoc. Petr. Geol. B., 97, 1937–1966, 2013.
Schauble, E. A., Ghosh, P., and Eiler, J. M.: Preferential formation of 13C-18O bonds in carbonate materials estimated using first-principle lattice dynamics, Geochim. Cosmochim. Ac., 70, 2510–2529, 2006.
Schauer, A. J., Kelson, J., Saenger, C., and Huntington, K. W.: Choice of 17O correction affects clumped isotope (Δ47) values of CO2 measured with mass spectrometry, Rapid Comm. Mass Sp., 30, 2607–2616, 2016.
Sewall, J. and Sloan, L.: Come a little bit closer: A high-resolution climate study of the early Paleogene Laramide foreland, Geology, 34, 81–84, 2006.
Sheldon, N. D. and Tabor, N. J.: Quantitative paleoenvironmental and paleoclimatic reconstruction using paleosols, Earth Sci. Rev., 95, 1–52, 2009.
Sheldon, N. D., Retallack, G. J., and Tanaka, S.: Geochemical climofunctions from North American soils and application to paleosols across the Eocene-Oligocene boundary in Oregon, J. Geol., 110, 687–696, 2002.
SIMNHP (Smithsonian Institution Museum of Natural History Paleobiology): Paleobiology Database, Smithsonian Institution (Washington, DC), available at: http://www.nmnh.si.edu/ (last access: July 2016), 2015.
Sloan, L. C.: Equable climates during the early Eocene: Significance of regional paleogeography for North American climate, Geology, 22, 881–884, 1994.
Sloan, L. C. and Barron, E.: “Equable” climates during Earth history, Geology, 18, 489–492, 1990.
Smith, M. E., Carroll, A. R., and Singer, B. S.: Synoptic reconstruction of a major ancient lake system: Eocene Green River, western United States, Geol. Soc. Am. Bull., 120, 54–84, 2008.
Smith, M. E., Chamberlain, K. R., Singer, B. S., and Carroll, A. R.: Eocene clocks agree: coeval 40Ar∕39Ar, U-Pb, and astronomical ages from the Green River Formation, Geology, 38, 527–530, 2010.
Smith, M. E., Carroll, A. R., Scott, J. J., and Singer, B. S.: Early Eocene carbon isotope excursions and landscape destabilization at eccentricity minima: Green River Formation of Wyoming, Earth Planet. Sc. Lett., 403, 393–406, 2014.
Smith, M. E., Carroll, A. R., and Scott, J. J.: Stratigraphic expression of climate tectonism, and geomorphic forcing in an underfilled lake basin: Wilkins Peak Member of the Green River Formation, in: Stratigraphy and Paleolimnology of the Green River Formation, edited by: Smith, M. E. and Carroll, A. R., Springer (Dordrecht, NE), 61–102, 2015.
Snell, K. E., Thrasher, B. L., Eiler, J. M., Koch, P. L., Sloan, L. C., and Tabor, N. J.: Hot summers in the Bighorn Basin during the early Paleogene, Geology, 41, 55–58, 2013.
Suarez, M. B., Passey, B. H., and Kaakinen, A.: Paleosol carbonate multiple isotopologue signature of active East Asian summer monsoons during the late Miocene and Pliocene, Geology, 39, 1151–1154, 2011.
Spicer, R. A. and Parrish, J. T.: Late Cretaceous–early Tertiary paleoclimates of northern high latitude: a quantitative view, J. Geol. Soc., 147, 329–341, 1990.
Spicer, R. A., Herman, A. B., Liao, W., Spicer, T. E. V., Kodrul, T. M., Yang, J., and Jin, J.: Cool tropics in the Middle Eocene: Evidence from the Changchang Flora, Hainan Island, China, Palaeogeogr. Palaeocl., 412, 1–16, 2014.
Stinchcomb, G. E., Nordt, L. C., Driese, S. G., Lukens, W. E., Williamson, F. C., and Tubbs, J. D.: A data-driven spline model designed to predict paleoclimate using paleosol geochemistry, Am. J. Sci., 316, 746–777, 2016.
Takeuchi, A., Larson, P. B., and Suzuki, K.: Influence of paleorelief on the Mid-Miocene climate variation in southeastern Washington, northeastern Oregon, and western Idaho, USA, Palaeogeogr. Palaeocl., 254, 462–476, 2007.
Thompson, R. S., Anderson, K. H., Pelltier, R. T., Strickland, L. E., Bartlein, P. J., and Shafer, S. L.: Quantitative estimation of climatic parameters from vegetation data in North America by the mutual climatic range technique, Quaternary Sci. Rev., 51, 18–39, 2012.
Thrasher, B. L. and Sloan, L. C.: Carbon dioxide and the early Eocene climate of western North America, Geology, 37, 807–810, 2009.
Thrasher, B. L. and Sloan, L. C.: Land cover influences on the regional climate of western North America during the early Eocene, Global Planet. Change, 72, 25–31, 2010.
TROPICOS: Global Plant Database: Missouri Botanical Garden (St. Louis, MO), available at: http://www.tropicos.org/ (last access: July 2016), 2015.
USDA (United States Department of Agriculture): The PLANTS Database: NRCS National Plant Data Team (Greensboro, NC), available at: http://plants.usda.gov (last access: July 2016), 2015.
Utescher, T., Bruch, A., Erdei, B., Francois, L., Ivanov, D., Jacques, F., Kern, A., Liu, Y., Mossbrugger, V., and Spicer, R.: The Coexistence Approach- Theoretical background and practical considerations of using plant fossils for climate quantification, Palaeogeogr. Palaeocl., 10, 58–73, 2014.
Wang, Q., Ferguson, D. K., Feng, G., Ablaev, A. G., Wang, Y., Yang, J., Li, Y., and Li, C.: Climatic change during the Palaeocene to Eocene based on fossil plants from Fushun China, Palaeogeogr. Palaeocl., 295, 323–331, 2010.
West, C. K., Greenwood, D. R., and Basinger, J. F.: Was the Arctic Eocene “rainforest” monsoonal? Estimates of seasonal precipitation from early Eocene megafloras from Ellesmere Island, Nunavut, Earth Planet. Sc. Lett., 427, 18–30, 2015.
Wilf, P.: Using fossil plants to understand global change: Evidence for Paleocene-Eocene warming in the greater Green River Basin of southwestern Wyoming, University of Pennsylvania (Philadelphia, PA), 384 pp., 1998.
Wilf, P.: Late Paleocene-early Eocene climate changes in southwestern Wyoming: Paleobotanical analysis, Geol. Soc. Am. Bull., 112, 292–307, 2000.
Wing, S. L.: Late Paleocene-early Eocene floral and climatic change in the Bighorn Basin, Wyoming, edited by: Aubrey, M., Lucas, S., and Berggren, W., Columbia University Press (New York, NY), 380–400, 1998.
Wolfe, J. A.: A paleobotanical interpretation of Tertiary climates in the Northern Hemisphere, Am. J. Sci., 66, 691–703, 1978.
Wolfe, J. A.: Paleoclimatic estimates from Tertiary leaf assemblages, Annu. Rev. Earth Pl. Sc., 23, 119–142, 1995.
Wolfe, J. A. and Wehr, W.: Middle Eocene dicotyledonous plants from Republic, northeastern Washington, USGS Bull., 1597, 67 pp., 1987.
Wolfe, J. A., Forest, C. E., and Molnar, P.: Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America, Geol. Soc. Am. Bull., 110, 664–678, 1998.
World Climate Research Programme: Climate Model Intercomparison Project (Phase 5), available at: https://cmip.llnl.gov/ (last access: January 2016), 2011.
Zaarur, S., Affek, H. P., and Brandon, M.: A revised calibration of the clumped isotope thermometer, Earth Planet. Sc. Lett., 382, 47–57, 2013.
Zachos, J., Pagani, M., Sloan, L., Thomas, E., and Billups, K.: Trends, rhythms, and aberrations in global climate 65 Ma to Present, Science, 292, 686–693, 2001.
Zachos, J. C., Dickens, G. R., and Zeebe, R. E.: An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics, Nature, 451, 279–283, 2008.
Zamanian, K., Pustovoytov, K., and Kuzyakov, Y.: Pedogenic carbonates: Forms and formation processes, Earth Sci. Rev., 157, 1–17, 2016.
Short summary
Climate equability is a paradox in paleoclimate research, but modeling suggests that strong seasonality should be a feature of greenhouse Earth periods too. Records of temperature from floral assemblages, paleosol geochemistry, clumped isotope thermometry, and downscaled models during the early Eocene show that the mean annual range of temperature was high, and may have increased during warming events. This has implications for predicting future seasonal climate impacts in continental regions.
Climate equability is a paradox in paleoclimate research, but modeling suggests that strong...