Articles | Volume 18, issue 6
https://doi.org/10.5194/cp-18-1385-2022
© Author(s) 2022. 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-18-1385-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The warm winter paradox in the Pliocene northern high latitudes
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
Alan M. Haywood
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
Ulrich Salzmann
Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK
Aisling M. Dolan
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
Tamara Fletcher
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
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Alan M. Haywood, Julia C. Tindall, Harry J. Dowsett, Aisling M. Dolan, Kevin M. Foley, Stephen J. Hunter, Daniel J. Hill, Wing-Le Chan, Ayako Abe-Ouchi, Christian Stepanek, Gerrit Lohmann, Deepak Chandan, W. Richard Peltier, Ning Tan, Camille Contoux, Gilles Ramstein, Xiangyu Li, Zhongshi Zhang, Chuncheng Guo, Kerim H. Nisancioglu, Qiong Zhang, Qiang Li, Youichi Kamae, Mark A. Chandler, Linda E. Sohl, Bette L. Otto-Bliesner, Ran Feng, Esther C. Brady, Anna S. von der Heydt, Michiel L. J. Baatsen, and Daniel J. Lunt
Clim. Past, 16, 2095–2123, https://doi.org/10.5194/cp-16-2095-2020, https://doi.org/10.5194/cp-16-2095-2020, 2020
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The large-scale features of middle Pliocene climate from the 16 models of PlioMIP Phase 2 are presented. The PlioMIP2 ensemble average was ~ 3.2 °C warmer and experienced ~ 7 % more precipitation than the pre-industrial era, although there are large regional variations. PlioMIP2 broadly agrees with a new proxy dataset of Pliocene sea surface temperatures. Combining PlioMIP2 and proxy data suggests that a doubling of atmospheric CO2 would increase globally averaged temperature by 2.6–4.8 °C.
Lauren E. Burton, Alan M. Haywood, Julia C. Tindall, Aisling M. Dolan, Daniel J. Hill, Erin L. McClymont, Sze Ling Ho, and Heather L. Ford
Clim. Past, 20, 1177–1194, https://doi.org/10.5194/cp-20-1177-2024, https://doi.org/10.5194/cp-20-1177-2024, 2024
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The Pliocene (~ 3 million years ago) is of interest because its warm climate is similar to projections of the future. We explore the role of atmospheric carbon dioxide in forcing sea surface temperature during the Pliocene by combining climate model outputs with palaeoclimate proxy data. We investigate whether this role changes seasonally and also use our data to suggest a new estimate of Pliocene climate sensitivity. More data are needed to further explore the results presented.
Julia E. Weiffenbach, Henk A. Dijkstra, Anna S. von der Heydt, Ayako Abe-Ouchi, Wing-Le Chan, Deepak Chandan, Ran Feng, Alan M. Haywood, Stephen J. Hunter, Xiangyu Li, Bette L. Otto-Bliesner, W. Richard Peltier, Christian Stepanek, Ning Tan, Julia C. Tindall, and Zhongshi Zhang
Clim. Past, 20, 1067–1086, https://doi.org/10.5194/cp-20-1067-2024, https://doi.org/10.5194/cp-20-1067-2024, 2024
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Elevated atmospheric CO2 concentrations and a smaller Antarctic Ice Sheet during the mid-Pliocene (~ 3 million years ago) cause the Southern Ocean surface to become fresher and warmer, which affects the global ocean circulation. The CO2 concentration and the smaller Antarctic Ice Sheet both have a similar and approximately equal impact on the Southern Ocean. The conditions of the Southern Ocean in the mid-Pliocene could therefore be analogous to those in a future climate with smaller ice sheets.
Guy J. G. Paxman, Stewart S. R. Jamieson, Aisling M. Dolan, and Michael J. Bentley
The Cryosphere, 18, 1467–1493, https://doi.org/10.5194/tc-18-1467-2024, https://doi.org/10.5194/tc-18-1467-2024, 2024
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This study uses airborne radar data and satellite imagery to map mountainous topography hidden beneath the Greenland Ice Sheet. We find that the landscape records the former extent and configuration of ice masses that were restricted to areas of high topography. Computer models of ice flow indicate that valley glaciers eroded this landscape millions of years ago when local air temperatures were at least 4 °C higher than today and Greenland’s ice volume was < 10 % of that of the modern ice sheet.
Xin Ren, Daniel J. Lunt, Erica Hendy, Anna von der Heydt, Ayako Abe-Ouchi, Bette Otto-Bliesner, Charles J. R. Williams, Christian Stepanek, Chuncheng Guo, Deepak Chandan, Gerrit Lohmann, Julia C. Tindall, Linda E. Sohl, Mark A. Chandler, Masa Kageyama, Michiel L. J. Baatsen, Ning Tan, Qiong Zhang, Ran Feng, Stephen Hunter, Wing-Le Chan, W. Richard Peltier, Xiangyu Li, Youichi Kamae, Zhongshi Zhang, and Alan M. Haywood
Clim. Past, 19, 2053–2077, https://doi.org/10.5194/cp-19-2053-2023, https://doi.org/10.5194/cp-19-2053-2023, 2023
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We investigate the Maritime Continent climate in the mid-Piacenzian warm period and find it is warmer and wetter and the sea surface salinity is lower compared with preindustrial period. Besides, the fresh and warm water transfer through the Maritime Continent was stronger. In order to avoid undue influence from closely related models in the multimodel results, we introduce a new metric, the multi-cluster mean, which could reveal spatial signals that are not captured by the multimodel mean.
Georgia R. Grant, Jonny H. T. Williams, Sebastian Naeher, Osamu Seki, Erin L. McClymont, Molly O. Patterson, Alan M. Haywood, Erik Behrens, Masanobu Yamamoto, and Katelyn Johnson
Clim. Past, 19, 1359–1381, https://doi.org/10.5194/cp-19-1359-2023, https://doi.org/10.5194/cp-19-1359-2023, 2023
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Regional warming will differ from global warming, and climate models perform poorly in the Southern Ocean. We reconstruct sea surface temperatures in the south-west Pacific during the mid-Pliocene, a time 3 million years ago that represents the long-term outcomes of 3 °C warming, which is expected for the future. Comparing these results to climate model simulations, we show that the south-west Pacific region will warm by 1 °C above the global average if atmospheric CO2 remains above 350 ppm.
Bjørg Risebrobakken, Mari F. Jensen, Helene R. Langehaug, Tor Eldevik, Anne Britt Sandø, Camille Li, Andreas Born, Erin Louise McClymont, Ulrich Salzmann, and Stijn De Schepper
Clim. Past, 19, 1101–1123, https://doi.org/10.5194/cp-19-1101-2023, https://doi.org/10.5194/cp-19-1101-2023, 2023
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In the observational period, spatially coherent sea surface temperatures characterize the northern North Atlantic at multidecadal timescales. We show that spatially non-coherent temperature patterns are seen both in further projections and a past warm climate period with a CO2 level comparable to the future low-emission scenario. Buoyancy forcing is shown to be important for northern North Atlantic temperature patterns.
Xiaofang Huang, Shiling Yang, Alan Haywood, Julia Tindall, Dabang Jiang, Yongda Wang, Minmin Sun, and Shihao Zhang
Clim. Past, 19, 731–745, https://doi.org/10.5194/cp-19-731-2023, https://doi.org/10.5194/cp-19-731-2023, 2023
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The sensitivity of climate to the height changes of the East Antarctic ice sheet (EAIS) during the mid-Pliocene has been assessed using the HadCM3 model. The results show that the height reduction of the EAIS leads to a warmer and wetter East Antarctica. However, unintuitively, both the surface air temperature and the sea surface temperature decrease over the rest of the globe. These findings could provide insights into future changes caused by warming-induced decay of the Antarctic ice sheet.
Lauren E. Burton, Alan M. Haywood, Julia C. Tindall, Aisling M. Dolan, Daniel J. Hill, Ayako Abe-Ouchi, Wing-Le Chan, Deepak Chandan, Ran Feng, Stephen J. Hunter, Xiangyu Li, W. Richard Peltier, Ning Tan, Christian Stepanek, and Zhongshi Zhang
Clim. Past, 19, 747–764, https://doi.org/10.5194/cp-19-747-2023, https://doi.org/10.5194/cp-19-747-2023, 2023
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Warm climates of the Pliocene (~ 3 million years ago) are similar to projections of the near future. We find elevated concentrations of atmospheric carbon dioxide to be the most important forcing for driving changes in Pliocene surface air temperature, sea surface temperature, and precipitation. However, changes caused by the nature of Pliocene ice sheets and orography are also important, affecting the extent to which we can use the Pliocene as an analogue for our warmer future.
Julia E. Weiffenbach, Michiel L. J. Baatsen, Henk A. Dijkstra, Anna S. von der Heydt, Ayako Abe-Ouchi, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Mark A. Chandler, Camille Contoux, Ran Feng, Chuncheng Guo, Zixuan Han, Alan M. Haywood, Qiang Li, Xiangyu Li, Gerrit Lohmann, Daniel J. Lunt, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Gilles Ramstein, Linda E. Sohl, Christian Stepanek, Ning Tan, Julia C. Tindall, Charles J. R. Williams, Qiong Zhang, and Zhongshi Zhang
Clim. Past, 19, 61–85, https://doi.org/10.5194/cp-19-61-2023, https://doi.org/10.5194/cp-19-61-2023, 2023
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We study the behavior of the Atlantic Meridional Overturning Circulation (AMOC) in the mid-Pliocene. The mid-Pliocene was about 3 million years ago and had a similar CO2 concentration to today. We show that the stronger AMOC during this period relates to changes in geography and that this has a significant influence on ocean temperatures and heat transported northwards by the Atlantic Ocean. Understanding the behavior of the mid-Pliocene AMOC can help us to learn more about our future climate.
Michael Amoo, Ulrich Salzmann, Matthew J. Pound, Nick Thompson, and Peter K. Bijl
Clim. Past, 18, 525–546, https://doi.org/10.5194/cp-18-525-2022, https://doi.org/10.5194/cp-18-525-2022, 2022
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Late Eocene to earliest Oligocene (37.97–33.06 Ma) climate and vegetation dynamics around the Tasmanian Gateway region reveal that changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation; a series of regional and global events, including a change in stratification of water masses and changes in pCO2, may have played significant roles.
Nick Thompson, Ulrich Salzmann, Adrián López-Quirós, Peter K. Bijl, Frida S. Hoem, Johan Etourneau, Marie-Alexandrine Sicre, Sabine Roignant, Emma Hocking, Michael Amoo, and Carlota Escutia
Clim. Past, 18, 209–232, https://doi.org/10.5194/cp-18-209-2022, https://doi.org/10.5194/cp-18-209-2022, 2022
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New pollen and spore data from the Antarctic Peninsula region reveal temperate rainforests that changed and adapted in response to Eocene climatic cooling, roughly 35.5 Myr ago, and glacially related disturbance in the early Oligocene, approximately 33.5 Myr ago. The timing of these events indicates that the opening of ocean gateways alone did not trigger Antarctic glaciation, although ocean gateways may have played a role in climate cooling.
Zixuan Han, Qiong Zhang, Qiang Li, Ran Feng, Alan M. Haywood, Julia C. Tindall, Stephen J. Hunter, Bette L. Otto-Bliesner, Esther C. Brady, Nan Rosenbloom, Zhongshi Zhang, Xiangyu Li, Chuncheng Guo, Kerim H. Nisancioglu, Christian Stepanek, Gerrit Lohmann, Linda E. Sohl, Mark A. Chandler, Ning Tan, Gilles Ramstein, Michiel L. J. Baatsen, Anna S. von der Heydt, Deepak Chandan, W. Richard Peltier, Charles J. R. Williams, Daniel J. Lunt, Jianbo Cheng, Qin Wen, and Natalie J. Burls
Clim. Past, 17, 2537–2558, https://doi.org/10.5194/cp-17-2537-2021, https://doi.org/10.5194/cp-17-2537-2021, 2021
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Understanding the potential processes responsible for large-scale hydrological cycle changes in a warmer climate is of great importance. Our study implies that an imbalance in interhemispheric atmospheric energy during the mid-Pliocene could have led to changes in the dynamic effect, offsetting the thermodynamic effect and, hence, altering mid-Pliocene hydroclimate cycling. Moreover, a robust westward shift in the Pacific Walker circulation can moisten the northern Indian Ocean.
Arthur M. Oldeman, Michiel L. J. Baatsen, Anna S. von der Heydt, Henk A. Dijkstra, Julia C. Tindall, Ayako Abe-Ouchi, Alice R. Booth, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Mark A. Chandler, Camille Contoux, Ran Feng, Chuncheng Guo, Alan M. Haywood, Stephen J. Hunter, Youichi Kamae, Qiang Li, Xiangyu Li, Gerrit Lohmann, Daniel J. Lunt, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Gabriel M. Pontes, Gilles Ramstein, Linda E. Sohl, Christian Stepanek, Ning Tan, Qiong Zhang, Zhongshi Zhang, Ilana Wainer, and Charles J. R. Williams
Clim. Past, 17, 2427–2450, https://doi.org/10.5194/cp-17-2427-2021, https://doi.org/10.5194/cp-17-2427-2021, 2021
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In this work, we have studied the behaviour of El Niño events in the mid-Pliocene, a period of around 3 million years ago, using a collection of 17 climate models. It is an interesting period to study, as it saw similar atmospheric carbon dioxide levels to the present day. We find that the El Niño events were less strong in the mid-Pliocene simulations, when compared to pre-industrial climate. Our results could help to interpret El Niño behaviour in future climate projections.
Charles J. R. Williams, Alistair A. Sellar, Xin Ren, Alan M. Haywood, Peter Hopcroft, Stephen J. Hunter, William H. G. Roberts, Robin S. Smith, Emma J. Stone, Julia C. Tindall, and Daniel J. Lunt
Clim. Past, 17, 2139–2163, https://doi.org/10.5194/cp-17-2139-2021, https://doi.org/10.5194/cp-17-2139-2021, 2021
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Computer simulations of the geological past are an important tool to improve our understanding of climate change. We present results from a simulation of the mid-Pliocene (approximately 3 million years ago) using the latest version of the UK’s climate model. The simulation reproduces temperatures as expected and shows some improvement relative to previous versions of the same model. The simulation is, however, arguably too warm when compared to other models and available observations.
Ellen Berntell, Qiong Zhang, Qiang Li, Alan M. Haywood, Julia C. Tindall, Stephen J. Hunter, Zhongshi Zhang, Xiangyu Li, Chuncheng Guo, Kerim H. Nisancioglu, Christian Stepanek, Gerrit Lohmann, Linda E. Sohl, Mark A. Chandler, Ning Tan, Camille Contoux, Gilles Ramstein, Michiel L. J. Baatsen, Anna S. von der Heydt, Deepak Chandan, William Richard Peltier, Ayako Abe-Ouchi, Wing-Le Chan, Youichi Kamae, Charles J. R. Williams, Daniel J. Lunt, Ran Feng, Bette L. Otto-Bliesner, and Esther C. Brady
Clim. Past, 17, 1777–1794, https://doi.org/10.5194/cp-17-1777-2021, https://doi.org/10.5194/cp-17-1777-2021, 2021
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The mid-Pliocene Warm Period (~ 3.2 Ma) is often considered an analogue for near-future climate projections, and model results from the PlioMIP2 ensemble show an increase of rainfall over West Africa and the Sahara region compared to pre-industrial conditions. Though previous studies of future projections show a west–east drying–wetting contrast over the Sahel, these results indicate a uniform rainfall increase over the Sahel in warm climates characterized by increased greenhouse gas forcing.
Daniel J. Lunt, Deepak Chandan, Alan M. Haywood, George M. Lunt, Jonathan C. Rougier, Ulrich Salzmann, Gavin A. Schmidt, and Paul J. Valdes
Geosci. Model Dev., 14, 4307–4317, https://doi.org/10.5194/gmd-14-4307-2021, https://doi.org/10.5194/gmd-14-4307-2021, 2021
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Often in science we carry out experiments with computers in which several factors are explored, for example, in the field of climate science, how the factors of greenhouse gases, ice, and vegetation affect temperature. We can explore the relative importance of these factors by
swapping in and outdifferent values of these factors, and can also carry out experiments with many different combinations of these factors. This paper discusses how best to analyse the results from such experiments.
Zhongshi Zhang, Xiangyu Li, Chuncheng Guo, Odd Helge Otterå, Kerim H. Nisancioglu, Ning Tan, Camille Contoux, Gilles Ramstein, Ran Feng, Bette L. Otto-Bliesner, Esther Brady, Deepak Chandan, W. Richard Peltier, Michiel L. J. Baatsen, Anna S. von der Heydt, Julia E. Weiffenbach, Christian Stepanek, Gerrit Lohmann, Qiong Zhang, Qiang Li, Mark A. Chandler, Linda E. Sohl, Alan M. Haywood, Stephen J. Hunter, Julia C. Tindall, Charles Williams, Daniel J. Lunt, Wing-Le Chan, and Ayako Abe-Ouchi
Clim. Past, 17, 529–543, https://doi.org/10.5194/cp-17-529-2021, https://doi.org/10.5194/cp-17-529-2021, 2021
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The Atlantic Meridional Overturning Circulation (AMOC) is an important topic in the Pliocene Model Intercomparison Project. Previous studies have suggested a much stronger AMOC during the Pliocene than today. However, our current multi-model intercomparison shows large model spreads and model–data discrepancies, which can not support the previous hypothesis. Our study shows good consistency with future projections of the AMOC.
David K. Hutchinson, Helen K. Coxall, Daniel J. Lunt, Margret Steinthorsdottir, Agatha M. de Boer, Michiel Baatsen, Anna von der Heydt, Matthew Huber, Alan T. Kennedy-Asser, Lutz Kunzmann, Jean-Baptiste Ladant, Caroline H. Lear, Karolin Moraweck, Paul N. Pearson, Emanuela Piga, Matthew J. Pound, Ulrich Salzmann, Howie D. Scher, Willem P. Sijp, Kasia K. Śliwińska, Paul A. Wilson, and Zhongshi Zhang
Clim. Past, 17, 269–315, https://doi.org/10.5194/cp-17-269-2021, https://doi.org/10.5194/cp-17-269-2021, 2021
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The Eocene–Oligocene transition was a major climate cooling event from a largely ice-free world to the first major glaciation of Antarctica, approximately 34 million years ago. This paper reviews observed changes in temperature, CO2 and ice sheets from marine and land-based records at this time. We present a new model–data comparison of this transition and find that CO2-forced cooling provides the best explanation of the observed global temperature changes.
Wesley de Nooijer, Qiong Zhang, Qiang Li, Qiang Zhang, Xiangyu Li, Zhongshi Zhang, Chuncheng Guo, Kerim H. Nisancioglu, Alan M. Haywood, Julia C. Tindall, Stephen J. Hunter, Harry J. Dowsett, Christian Stepanek, Gerrit Lohmann, Bette L. Otto-Bliesner, Ran Feng, Linda E. Sohl, Mark A. Chandler, Ning Tan, Camille Contoux, Gilles Ramstein, Michiel L. J. Baatsen, Anna S. von der Heydt, Deepak Chandan, W. Richard Peltier, Ayako Abe-Ouchi, Wing-Le Chan, Youichi Kamae, and Chris M. Brierley
Clim. Past, 16, 2325–2341, https://doi.org/10.5194/cp-16-2325-2020, https://doi.org/10.5194/cp-16-2325-2020, 2020
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The simulations for the past climate can inform us about the performance of climate models in different climate scenarios. Here, we analyse Arctic warming in an ensemble of 16 simulations of the mid-Pliocene Warm Period (mPWP), when the CO2 level was comparable to today. The results highlight the importance of slow feedbacks in the model simulations and imply that we must be careful when using simulations of the mPWP as an analogue for future climate change.
Alan M. Haywood, Julia C. Tindall, Harry J. Dowsett, Aisling M. Dolan, Kevin M. Foley, Stephen J. Hunter, Daniel J. Hill, Wing-Le Chan, Ayako Abe-Ouchi, Christian Stepanek, Gerrit Lohmann, Deepak Chandan, W. Richard Peltier, Ning Tan, Camille Contoux, Gilles Ramstein, Xiangyu Li, Zhongshi Zhang, Chuncheng Guo, Kerim H. Nisancioglu, Qiong Zhang, Qiang Li, Youichi Kamae, Mark A. Chandler, Linda E. Sohl, Bette L. Otto-Bliesner, Ran Feng, Esther C. Brady, Anna S. von der Heydt, Michiel L. J. Baatsen, and Daniel J. Lunt
Clim. Past, 16, 2095–2123, https://doi.org/10.5194/cp-16-2095-2020, https://doi.org/10.5194/cp-16-2095-2020, 2020
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The large-scale features of middle Pliocene climate from the 16 models of PlioMIP Phase 2 are presented. The PlioMIP2 ensemble average was ~ 3.2 °C warmer and experienced ~ 7 % more precipitation than the pre-industrial era, although there are large regional variations. PlioMIP2 broadly agrees with a new proxy dataset of Pliocene sea surface temperatures. Combining PlioMIP2 and proxy data suggests that a doubling of atmospheric CO2 would increase globally averaged temperature by 2.6–4.8 °C.
Cited articles
Abbot, D. S. and Tziperman, E.: Sea ice, high-latitude convection, and equable climates, Geophys. Res. Lett., 35, L03702, https://doi.org/10.1029/2007GL032286, 2008. a, b
Ager, T. A., Matthews, J. V., and Yeend, W.: Pliocene terrace gravels of the ancestral Yukon River near Circle, Alaska: Palynology, paleobotany, paleoenvironmental reconstruction and regional correlation, Quatern. Int., 22–23, 185–206, https://doi.org/10.1016/1040-6182(94)90012-4, 1994. a
Arnold, N. P., Branson, M., Burt, M. A., Abbot, D. S., Kuang, Z., Randall, D. A., and Tziperman, E.: Effects of explicit atmospheric convection at high CO2, P. Natl. Acad. Sci. USA, 111, 10943–10948, https://doi.org/10.1073/pnas.1407175111, 2014. a
Baatsen, M. L. J., von der Heydt, A. S., Kliphuis, M. A., Oldeman, A. M., and Weiffenbach, J. E.: Warm mid-Pliocene conditions without high climate sensitivity: the CCSM4-Utrecht (CESM 1.0.5) contribution to the PlioMIP2, Clim. Past, 18, 657–679, https://doi.org/10.5194/cp-18-657-2022, 2022. a
Ballantyne, A. P., Greenwood, D. R., Damste, J. S. S., Csank, A. Z., Eberle, J. J., and Rybczynski, N.: Significantly warmer Arctic surface temperatures during the Pliocene indicated by multiple independent proxies, Geology, 38, 603–606, https://doi.org/10.1130/G30815.1, 2010. a
Barendregt, R. W., Matthews Jr, J. V., Behan-Pelletier, V., Brigham-Grette, J., Fyles, J. G., Ovenden, L. E., McNeil, D. H., Brouwers, E., Marincovich, L., Rybczynski, N., and Fletcher, T. L. (Eds.): Biostratigraphy, Age, and Paleoenvironment of the Pliocene Beaufort Formation on Meighen Island, Canadian Arctic Archipelago, Geological Society of America, https://doi.org/10.1130/2021.2551(01), 2021. a, b
Brigham-Grette, J., Melles, M., Minyuk, P., Andreev, A., Tarasov, P., DeConto, R., Koenig, S., Nowaczyk, N., Wennrich, V., Rosen, P., Haltia, E., Cook, T., Gebhardt, C., Meyer-Jacob, C., Snyder, J., and Herzschuh, U.: Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia, Science, 340, 1421–1427, https://doi.org/10.1126/science.1233137, 2013. a
Burke, K. D., Williams, J. W., Chandler, M. A., Haywood, A. M., Lunt, D. J., and Otto-Bliesner, B. L.: Pliocene and Eocene provide best analogs for near-future climates, P. Natl. Acad. Sci. USA, 115, 13288–13293, https://doi.org/10.1073/pnas.1809600115, 2018. a
Chan, W.-L. and Abe-Ouchi, A.: Pliocene Model Intercomparison Project (PlioMIP2) simulations using the Model for Interdisciplinary Research on Climate (MIROC4m), Clim. Past, 16, 1523–1545, https://doi.org/10.5194/cp-16-1523-2020, 2020. a
Chandan, D. and Peltier, W. R.: Regional and global climate for the mid-Pliocene using the University of Toronto version of CCSM4 and PlioMIP2 boundary conditions, Clim. Past, 13, 919–942, https://doi.org/10.5194/cp-13-919-2017, 2017. a
Csank, A. Z., Tripati, A. K., Patterson, W. P., Eagle, R. A., Rybczynski, N., Ballantyne, A. P., and Eiler, J. M.: Estimates of Arctic land surface temperatures during the early Pliocene from two novel proxies, Earth Planet. Sc. Lett., 304, 291–299, https://doi.org/10.1016/j.epsl.2011.02.030, 2011. a
de la Vega, E., Chalk, T. B., Wilson, P. A., Bysani, R. P., and Foster, G. L.: Atmospheric CO2 during the Mid-Piacenzian Warm Period and the M2 glaciation, Scientific Reports, 10, 11002, https://doi.org/10.1038/s41598-020-67154-8, 2020. a
Demske, D., Mohr, B., and Oberhansli, H.: Late Pliocene vegetation and climate of the Lake Baikal region, southern East Siberia, reconstructed from palynological data, Palaeogeogr. Palaeocl., 184, 107–129, https://doi.org/10.1016/S0031-0182(02)00251-1, 2002. a, b
de Nooijer, W., Zhang, Q., Li, Q., Zhang, Q., Li, X., Zhang, Z., Guo, C., Nisancioglu, K. H., Haywood, A. M., Tindall, J. C., Hunter, S. J., Dowsett, H. J., Stepanek, C., Lohmann, G., Otto-Bliesner, B. L., Feng, R., Sohl, L. E., Chandler, M. A., Tan, N., Contoux, C., Ramstein, G., Baatsen, M. L. J., von der Heydt, A. S., Chandan, D., Peltier, W. R., Abe-Ouchi, A., Chan, W.-L., Kamae, Y., and Brierley, C. M.: Evaluation of Arctic warming in mid-Pliocene climate simulations, Clim. Past, 16, 2325–2341, https://doi.org/10.5194/cp-16-2325-2020, 2020. a, b
Dowsett, H., Dolan, A., Rowley, D., Moucha, R., Forte, A. M., Mitrovica, J. X., Pound, M., Salzmann, U., Robinson, M., Chandler, M., Foley, K., and Haywood, A.: The PRISM4 (mid-Piacenzian) paleoenvironmental reconstruction, Clim. Past, 12, 1519–1538, https://doi.org/10.5194/cp-12-1519-2016, 2016. a, b, c
Dowsett, H. J., Robinson, M. M., Haywood, A. M., Hill, D. J., Dolan, A. M., Stoll, D. K., Chan, W. L., Abe-Ouchi, A., Chandler, M. A., Rosenbloom, N. A., Otto-Bliesner, B. L., Bragg, F. J., Lunt, D. J., Foley, K. M., and Riesselman, C. R.: Assessing confidence in Pliocene sea surface temperatures to evaluate predictive models, Nat. Clim. Change, 2, 365–371, 2012. a
Dowsett, H. J., Foley, K. M., Stoll, D. K., Chandler, M. A., Sohl, L. E., Bentsen, M., Otto-Bliesner, B. L., Bragg, F. J., Chan, W.-L., Contoux, C., Dolan, A. M., Haywood, A. M., Jonas, J. A., Jost, A., Kamae, Y., Lohmann, G., Lunt, D. J., Nisancioglu, K. H., Abe-Ouchi, A., Ramstein, G., Riesselman, C. R., Robinson, M. M., Rosenbloom, N. A., Salzmann, U., Stepanek, C., Strother, S. L., Ueda, H., Yan, Q., and Zhang, Z.: Sea Surface Temperature of the mid-Piacenzian Ocean: A Data-Model Comparison, Scientific Reports, 3, 2013, https://doi.org/10.1038/srep02013, 2013. a, b
Elias, S. and Matthews, J.: Arctic North American seasonal temperatures from the latest Miocene to the Early Pleistocene, based on mutual climatic range analysis of fossil beetle assemblages, Can. J. Earth Sci., 39, 911–920, https://doi.org/10.1139/E01-096, 2002. a, b
Elias, S., Anderson, K., and Andrews, J.: Late Wisconsin climate in northeastern USA and southeastern Canada, reconstructed from fossil beetle assemblages, J. Quaternary Sci., 11, 417–421, 1996. a
Feng, R., Otto-Bliesner, B. L., Fletcher, T. L., Tabor, C. R., Ballantyne, A. P., and Brady, E. C.: Amplified Late Pliocene terrestrial warmth in northern high latitudes from greater radiative forcing and closed Arctic Ocean gateways, Earth. Planet. Sc. Lett., 466, 129–138, https://doi.org/10.1016/j.epsl.2017.03.006, 2017. a, b
Feng, R., Otto-Bliesner, B. L., Brady, E. C., and Rosenbloom, N.: Increased Climate Response and Earth System Sensitivity From CCSM4 to CESM2 in Mid-Pliocene Simulations, J. Adv. Model. Earth Sy., 12, e2019MS002033, https://doi.org/10.1029/2019MS002033, 2020. a, b, c
Fletcher, T., Feng, R., Telka, A. M., Matthews Jr., J. V., and Ballantyne, A.: Floral Dissimilarity and the Influence of Climate in the Pliocene High Arctic: Biotic and Abiotic Influences on Five Sites on the Canadian Arctic Archipelago, Frontiers in Ecology and Evolution, 5, 19, https://doi.org/10.3389/fevo.2017.00019, 2017. a, b, c, d
Fletcher, T. L., Warden, L., Sinninghe Damsté, J. S., Brown, K. J., Rybczynski, N., Gosse, J. C., and Ballantyne, A. P.: Evidence for fire in the Pliocene Arctic in response to amplified temperature, Clim. Past, 15, 1063–1081, https://doi.org/10.5194/cp-15-1063-2019, 2019b. a, b, c
Fyles, J., Hills, L., Matthews Jr., J. V., Barendregt, R., Baker, J., Irving, E., and Jette, H.: Ballast Brook and Beaufort Formations (late Tertiary) on North Banks Island, Arctic Canada, Quatern. Int., 22–23, 141–171, https://doi.org/10.1016/1040-6182(94)90010-8, 1997. a
Gordon, C., Cooper, C., Senior, C., Banks, H., Gregory, J., Johns, T., Mitchell, J., and Wood, R.: The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments, Clim. Dynam., 16, 147–168, 2000. a
Greenwood, D. and Wing, S.: Eocene Continental Climates and Latitudinal Temperature-Gradients, Geology, 23, 1044–1048, https://doi.org/10.1130/0091-7613(1995)023<1044:ECCALT>2.3.CO;2, 1995. a
Harbert, R. S. and Baryiames, A. A.: cRacle: R tools for estimating climate from vegetation, Appl. Plant Sci., 8, e11322, https://doi.org/10.1002/aps3.11322, 2020. a
Harbert, R. S. and Nixon, K. C.: Climate reconstruction analysis using coexistence likelihood estimation (CRACLE): A method for the estimation of climate using vegetation, Am. J. Bot., 102, 1277–1289, https://doi.org/10.3732/ajb.1400500, 2015. a, b, c
Harris, I., Osborn, T. J., Jones, P., and Lister, D.: Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset, Scientific Data, 7, 109, https://doi.org/10.1038/s41597-020-0453-3, 2020. a
Haywood, A. M., Dowsett, H. J., Otto-Bliesner, B., Chandler, M. A., Dolan, A. M., Hill, D. J., Lunt, D. J., Robinson, M. M., Rosenbloom, N., Salzmann, U., and Sohl, L. E.: Pliocene Model Intercomparison Project (PlioMIP): experimental design and boundary conditions (Experiment 1), Geosci. Model Dev., 3, 227–242, https://doi.org/10.5194/gmd-3-227-2010, 2010. a
Haywood, A. M., Dolan, A. M., Pickering, S. J., Dowsett, H. J., McClymont, E. L., Prescott, C. L., Salzmann, U., Hill, D. J., Hunter, S. J., Lunt, D. J., Pope, J. O., and Valdes, P. J.: On the identification of a Pliocene time slice for data-model comparison, Philos. T. Roy. Soc. A, 371, 20120515, https://doi.org/10.1098/rsta.2012.0515, 2013. a, b, c
Haywood, A. M., Dowsett, H. J., and Dolan, A. M.: Integrating geological archives and climate models for the mid-Pliocene warm period, Nat. Commun., 7, 10646, https://doi.org/10.1038/ncomms10646, 2016a. a
Haywood, A. M., Dowsett, H. J., Dolan, A. M., Rowley, D., Abe-Ouchi, A., Otto-Bliesner, B., Chandler, M. A., Hunter, S. J., Lunt, D. J., Pound, M., and Salzmann, U.: The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: scientific objectives and experimental design, Clim. Past, 12, 663–675, https://doi.org/10.5194/cp-12-663-2016, 2016b. a
Haywood, A. M., Tindall, J. C., Dowsett, H. J., Dolan, A. M., Foley, K. M., Hunter, S. J., Hill, D. J., Chan, W.-L., Abe-Ouchi, A., Stepanek, C., Lohmann, G., Chandan, D., Peltier, W. R., Tan, N., Contoux, C., Ramstein, G., Li, X., Zhang, Z., Guo, C., Nisancioglu, K. H., Zhang, Q., Li, Q., Kamae, Y., Chandler, M. A., Sohl, L. E., Otto-Bliesner, B. L., Feng, R., Brady, E. C., von der Heydt, A. S., Baatsen, M. L. J., and Lunt, D. J.: The Pliocene Model Intercomparison Project Phase 2: large-scale climate features and climate sensitivity, Clim. Past, 16, 2095–2123, https://doi.org/10.5194/cp-16-2095-2020, 2020. a, b, c, d, e, f, g
Hill, D. J.: The non-analogue nature of Pliocene temperature gradients, Earth. Planet. Sc. Lett., 425, 232–241, https://doi.org/10.1016/j.epsl.2015.05.044, 2015. a, b, c
Hopcroft, P. O., Ramstein, G., Pugh, T. A. M., Hunter, S. J., Murguia-Flores, F., Quiquet, A., Sun, Y., Tan, N., and Valdes, P. J.: Polar amplification of Pliocene climate by elevated trace gas radiative forcing, P. Natl. Acad. Sci. USA, 117, 23401–23407, https://doi.org/10.1073/pnas.2002320117, 2020. a
Howell, F. W., Haywood, A. M., Dowsett, H. J., and Pickering, S. J.: Sensitivity of Pliocene Arctic climate to orbital forcing, atmospheric CO2 and sea ice albedo parameterisation, Earth. Planet. Sc. Lett., 441, 133–142, https://doi.org/10.1016/j.epsl.2016.02.036, 2016. a, b, c
Huang, B., Thorne, P. W., Banzon, V. F., Boyer, T., Chepurin, G., Lawrimore, J. H., Menne, M. J., Smith, T. M., Vose, R. S., and Zhang, H.-M.: Extended Reconstructed Sea Surface Temperature, Version 5 (ERSSTv5): Upgrades, Validations, and Intercomparisons, J. Climate, 30, 8179–8205, https://doi.org/10.1175/JCLI-D-16-0836.1, 2017. a
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. a
Huber, M. and Sloan, L.: Heat transport, deep waters, and thermal gradients: Coupled simulation of an Eocene Greenhouse Climate, Geophys. Res. Lett., 28, 3481–3484, https://doi.org/10.1029/2001GL012943, 2001. a
Hunter, S. J., Haywood, A. M., Dolan, A. M., and Tindall, J. C.: The HadCM3 contribution to PlioMIP phase 2, Clim. Past, 15, 1691–1713, https://doi.org/10.5194/cp-15-1691-2019, 2019. a
Huppert, A. and Solow, A.: A method for reconstructing climate from fossil beetle assemblages, P. Roy. Soc. B-Biol. Sci., 271, 1125–1128, https://doi.org/10.1098/rspb.2004.2706, 2004. a
Hyland, E. G., Huntington, K. W., Sheldon, N. D., and Reichgelt, T.: Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum, Clim. Past, 14, 1391–1404, https://doi.org/10.5194/cp-14-1391-2018, 2018. a
Kageyama, M., Harrison, S. P., Kapsch, M.-L., Lofverstrom, M., Lora, J. M., Mikolajewicz, U., Sherriff-Tadano, S., Vadsaria, T., Abe-Ouchi, A., Bouttes, N., Chandan, D., Gregoire, L. J., Ivanovic, R. F., Izumi, K., LeGrande, A. N., Lhardy, F., Lohmann, G., Morozova, P. A., Ohgaito, R., Paul, A., Peltier, W. R., Poulsen, C. J., Quiquet, A., Roche, D. M., Shi, X., Tierney, J. E., Valdes, P. J., Volodin, E., and Zhu, J.: The PMIP4 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3 simulations, Clim. Past, 17, 1065–1089, https://doi.org/10.5194/cp-17-1065-2021, 2021. a
Kamae, Y., Yoshida, K., and Ueda, H.: Sensitivity of Pliocene climate simulations in MRI-CGCM2.3 to respective boundary conditions, Clim. Past, 12, 1619–1634, https://doi.org/10.5194/cp-12-1619-2016, 2016. a
Kaplan, J. O.: Geophysical Applications of Vegetation Modeling, PhD thesis, Lund University, Lund, ISBN 91-7874-089-4, 2001. a
Kaplan, J. O., Bigelow, N., Prentice, I., Harrison, S., Bartlein, P., Christensen, T., Cramer, W., Matveyeva, N., McGuire, A., Murray, D., Razzhivin, V., Smith, B., Walker, D., Anderson, P., Andreev, A., Brubaker, L., Edwards, M., and Lozhkin, A.: Climate change and Arctic ecosystems: 2. Modeling, paleodata-model comparisons, and future projections, J. Geophys. Res, 108, 8171, https://doi.org/10.1029/2002JD002559, 2003. a
Klages, J. P., Salzmann, U., Bickert, T., Hillenbrand, C.-D., Gohl, K., Kuhn, G., Bohaty, S. M., Titschack, J., Mueller, J., Frederichs, T., Bauersachs, T., Ehrmann, W., van de Flierdt, T., Pereira, P. S., Larter, R. D., Lohmann, G., Niezgodzki, I., Uenzelmann-Neben, G., Zundel, M., Spiegel, C., Mark, C., Chew, D., Francis, J. E., Nehrke, G., Schwarz, F., Smith, J. A., Freudenthal, T., Esper, O., Paelike, H., Ronge, T. A., Dziadek, R., and the Science Team of Expedition PS104: Temperate rainforests near the South Pole during peak Cretaceous warmth, Nature, 580, 81–86, https://doi.org/10.1038/s41586-020-2148-5, 2020. a, b
Korner, C., Basler, D., Hoch, G., Kollas, C., Lenz, A., Randin, C. F., Vitasse, Y., and Zimmermann, N. E.: Where, why and how? Explaining the low-temperature range limits of temperate tree species, J. Ecol., 104, 1076–1088, https://doi.org/10.1111/1365-2745.12574, 2016. a, b
Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A., and Levrard, B.: A long-term numerical solution for the insolation quantities of the Earth, Astron. Astrophys., 428, 261–285, https://doi.org/10.1051/0004-6361:20041335, 2004. a
Li, X., Guo, C., Zhang, Z., Otterå, O. H., and Zhang, R.: PlioMIP2 simulations with NorESM-L and NorESM1-F, Clim. Past, 16, 183–197, https://doi.org/10.5194/cp-16-183-2020, 2020. a, b
Lunt, D. J., Bragg, F., Chan, W.-L., Hutchinson, D. K., Ladant, J.-B., Morozova, P., Niezgodzki, I., Steinig, S., Zhang, Z., Zhu, J., Abe-Ouchi, A., Anagnostou, E., de Boer, A. M., Coxall, H. K., Donnadieu, Y., Foster, G., Inglis, G. N., Knorr, G., Langebroek, P. M., Lear, C. H., Lohmann, G., Poulsen, C. J., Sepulchre, P., Tierney, J. E., Valdes, P. J., Volodin, E. M., Dunkley Jones, T., Hollis, C. J., Huber, M., and Otto-Bliesner, B. L.: DeepMIP: model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data, Clim. Past, 17, 203–227, https://doi.org/10.5194/cp-17-203-2021, 2021. a
Matthews Jr., J. V. and Fyles, J. G.: Late Tertiary plant and arthropod fossils from the high-terrace sediments on the Fosheim Peninsula, Ellesmere Island, Nunavut, in: Environmental Response to Climate Change in the Canadian High Arctic, Geological Survey of Canada, Bulletin 529, 295–317, https://doi.org/10.4095/211969, 2000. a
Mauri, A., Davis, B. A. S., Collins, P. M., and Kaplan, J. O.: The climate of Europe during the Holocene: a gridded pollen-based reconstruction and its multi-proxy evaluation, Quaternary Sci. Rev., 112, 109–127, https://doi.org/10.1016/j.quascirev.2015.01.013, 2015. a
McClymont, E. L., Ford, H. L., Ho, S. L., Tindall, J. C., Haywood, A. M., Alonso-Garcia, M., Bailey, I., Berke, M. A., Littler, K., Patterson, M. O., Petrick, B., Peterse, F., Ravelo, A. C., Risebrobakken, B., De Schepper, S., Swann, G. E. A., Thirumalai, K., Tierney, J. E., van der Weijst, C., White, S., Abe-Ouchi, A., Baatsen, M. L. J., Brady, E. C., Chan, W.-L., Chandan, D., Feng, R., Guo, C., von der Heydt, A. S., Hunter, S., Li, X., Lohmann, G., Nisancioglu, K. H., Otto-Bliesner, B. L., Peltier, W. R., Stepanek, C., and Zhang, Z.: Lessons from a high-CO2 world: an ocean view from ∼3 million years ago, Clim. Past, 16, 1599–1615, https://doi.org/10.5194/cp-16-1599-2020, 2020. a, b, c, d, e, f
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, https://doi.org/10.1016/S0031-0182(96)00154-X, 1997. a, b
Overpeck, J. T., Webb III, T., and Prentice, I. C.: Quantitative Interpretation of Fossil Pollen Spectra – Dissimilarity Coefficients and the Method of Modern Analogs, Quaternary Res., 23, 87–108, https://doi.org/10.1016/0033-5894(85)90074-2, 1985. a
Pope, J. O., Collins, M., Haywood, A. M., Dowsett, H. J., Hunter, S. J., Lunt, D. J., Pickering, S. J., and Pound, M. J.: Quantifying Uncertainty in Model Predictions for the Pliocene (Plio-QUMP): Initial results, Palaeogeogr. Palaeocl., 309, 128–140, https://doi.org/10.1016/j.palaeo.2011.05.004, 2011. a
Popova, S., Utescher, T., Gromyko, D., Bruch, A. A., and Mosbrugger, V.: Palaeoclimate Evolution in Siberia and the Russian Far East from the Oligocene to Pliocene – Evidence from Fruit and Seed Floras, Turk. J. Earth Sci., 21, 315–334, https://doi.org/10.3906/yer-1005-6, 2012. a, b, c, d, e, f, g, h, i, j
Pound, M. J., Tindall, J., Pickering, S. J., Haywood, A. M., Dowsett, H. J., and Salzmann, U.: Late Pliocene lakes and soils: a global data set for the analysis of climate feedbacks in a warmer world, Clim. Past, 10, 167–180, https://doi.org/10.5194/cp-10-167-2014, 2014. a
Prescott, C. L., Dolan, A. M., Haywood, A. M., Hunter, S. J., and Tindall, J. C.: Regional climate and vegetation response to orbital forcing within the mid-Pliocene Warm Period: A study using HadCM3, Global Planet. Change, 161, 231–243, https://doi.org/10.1016/j.gloplacha.2017.12.015, 2018. a, b
Salzmann, U., Dolan, A. M., Haywood, A. M., Chan, W. L., Voss, J., Hill, D. J., Abe-Ouchi, A., Otto-Bliesner, B., Bragg, F. J., Chandler, M. A., Contoux, C., Dowsett, H. J., Jost, A., Kamae, Y., Lohmann, G., Lunt, D. J., Pickering, S. J., Pound, M. J., Ramstein, G., Rosenbloom, N. A., Sohl, L., Stepanek, C., Ueda, H., and Zhang, Z. S.: Challenges in quantifying Pliocene terrestrial warming revealed by data-model discord, Nat. Clim. Change, 3, 969–974, 2013. a, b, c, d
Stepanek, C., Samakinwa, E., Knorr, G., and Lohmann, G.: Contribution of the coupled atmosphere–ocean–sea ice–vegetation model COSMOS to the PlioMIP2, Clim. Past, 16, 2275–2323, https://doi.org/10.5194/cp-16-2275-2020, 2020. a
Tan, N., Contoux, C., Ramstein, G., Sun, Y., Dumas, C., Sepulchre, P., and Guo, Z.: Modeling a modern-like pCO2 warm period (Marine Isotope Stage KM5c) with two versions of an Institut Pierre Simon Laplace atmosphere–ocean coupled general circulation model, Clim. Past, 16, 1–16, https://doi.org/10.5194/cp-16-1-2020, 2020.
a, b
Unger, N. and Yue, X.: Strong chemistry-climate feedbacks in the Pliocene, Geophys. Res. Lett., 41, 527–533, https://doi.org/10.1002/2013GL058773, 2014. a
Williams, C. J. R., Sellar, A. A., Ren, X., Haywood, A. M., Hopcroft, P., Hunter, S. J., Roberts, W. H. G., Smith, R. S., Stone, E. J., Tindall, J. C., and Lunt, D. J.: Simulation of the mid-Pliocene Warm Period using HadGEM3: experimental design and results from model–model and model–data comparison, Clim. Past, 17, 2139–2163, https://doi.org/10.5194/cp-17-2139-2021, 2021. a
Zheng, J., Zhang, Q., Li, Q., Zhang, Q., and Cai, M.: Contribution of sea ice albedo and insulation effects to Arctic amplification in the EC-Earth Pliocene simulation, Clim. Past, 15, 291–305, https://doi.org/10.5194/cp-15-291-2019, 2019. a
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Short summary
The mid-Pliocene (MP; ∼3.0 Ma) had CO2 levels similar to today and average temperatures ∼3°C warmer. At terrestrial high latitudes, MP temperatures from climate models are much lower than those reconstructed from data. This mismatch occurs in the winter but not the summer. The winter model–data mismatch likely has multiple causes. One novel cause is that the MP climate may be outside the modern sample, and errors could occur when using information from the modern era to reconstruct climate.
The mid-Pliocene (MP; ∼3.0 Ma) had CO2 levels similar to today and average temperatures ∼3°C...