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Early Eocene Climatic Optimum

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The Early Eocene Climatic Optimum (EECO), also referred to as the Early Eocene Thermal Maximum (EETM),[1] was a period of extremely warm greenhouse climatic conditions during the Eocene epoch. The EECO represented the hottest sustained interval of the Cenozoic era and one of the hottest periods in all of Earth's history.[2]

Duration

The EECO lasted from about 54 to 49 Ma.[1] The EECO's onset is signified by a major geochemical enrichment in isotopically light carbon, commonly known as a negative δ13C excursion, that demarcates the hyperthermal Eocene Thermal Maximum 3 (ETM3).[3]

Climate

Following some climate models, the EECO was marked by an extremely high global mean surface temperature,[1] which has been estimated to be anywhere between 23.2 and 29.7 °C, with the mean estimate being around 27.0 °C.[4] In North America, the mean annual temperature was 23.0 °C, while the continent's overall mean annual precipitation (MAP) was about 1500 mm.[2] The mean annual temperature range (MATR) of North America may have been as low as 47 °C or as high as 61 °C, while the MATR of Asia was anywhere from 51 to 60 °C.[5] The Okanagan Highlands had a moist mesothermal climate, with bioclimatic analysis of the region yielding estimates of a mean annual temperature (MAT) of 12.7-16.6 °C, a cold month mean temperature (CMMT) of 3.5-7.9 °C, and a MAP of 103-157 cm.[6] Clumped isotope measurements from the Green River Basin confirm a high seasonality of temperature, contradicting climatological predictions of an equable climate under greenhouse conditions.[7] Sediments from San Diego County, California record a MAP of 1100 ± 299 mm, notably drier than the region was during the Palaeocene-Eocene Thermal Maximum.[8] Sea surface temperatures (SSTs) off of Seymour Island were ~15 °C.[9] The high elevation areas of Asia, Africa, and Antarctica saw elevation dependent warming (EDW), while those in North America and India saw elevation dependent cooling (EDC).[10]

The latitudinal climate gradient is generally believed to have been smaller, which was mainly the result of a decrease in albedo differences across Earth's surface.[11] Although SSTs are often believed to have had a shallow latitudinal temperature gradient, this is likely to be an artefact of burial-induced oxygen isotope reequilibration in fossilised benthic foraminifera.[12]

Climate modelling simulations point to a carbon dioxide concentration in the atmosphere of about 1,680 ppm to reproduce the observed hothouse conditions of the EECO,[13] although geochemical proxies suggest only 700-900 ppm.[14] Stomatal density in Gingko leaves suggests pCO2 was over twice that of preindustrial levels.[15] Additionally, methane concentrations in the Early Eocene may have been significantly higher than in the present day.[16]

The nature of the hydrological cycle during the EECO is controversial. Evidence from German peat bogs suggests that it was highly variable, with alternations between aridity and humidity.[17] Evidence from North America, in contrast, suggests that the hydrological cycle was enhanced during the EECO, although it remained relatively stable, unlike during the earlier hyperthermals, and that the stable hydroclimate may ultimately have ended the EECO by enabling high rates of organic carbon burial in lacustrine settings.[18]

Causes

The EECO was preceded by a major long-term warming trend in the Late Palaeocene and Early Eocene.[19] It was initiated by a series of intense hyperthermal events in the Early Eocene, including Eocene Thermal Maximum 2 (ETM2) and ETM3.[20]

The emplacement of the Pana Formation, a volcanic rock formation in southern Tibet that may represent the product of a supereruption, has also been proposed as a source of excess carbon flux into the atmosphere that drove the EECO.[21] Other research attributes the elevated greenhouse gas levels to increased generation of petroleum in sedimentary basins and enhanced ventilation of marine carbon.[22]

Biotic effects

The final phase of the Angiosperm Terrestrial Revolution occurred during the EECO.[23] The supergreenhouse climate of the EECO fostered extensive floral diversification and increased habitat complexity in North American terrestrial biomes.[2] The hot, humid conditions of the EECO may have facilitated the evolution of epiphytic bryophytes, with the oldest member of Lejeuneaceae being described from fossils from the Cambay amber dating back to the EECO.[24] The Okanagan Highlands in British Columbia became a biodiversity hotspot from which newly evolved lineages of temperate-adapted plants radiated from following the end of the EECO.[25]

The climate was warm enough to allow palms and palm beetles to inhabit upland regions of British Columbia and Washington.[26] Ellesmere Island became inhabited by basal primatomorphs.[27]

Northern Yakutia was covered in mangroves.[28] Mongolia witnessed a humidification event that transformed it from a shrubland into a forest and significantly reducing local wildfire incidence.[29]

In South America, the EECO coincided with the Itaboraian South American Land Mammal Age.[30] Cingulates diversified over the course of the EECO.[31]

The northern margins of the Australo-Antarctic Gulf, then located at 60-65 °S, were covered in wet-tropical lowland vegetation.[32]

The euryhaline dinoflagellate Homotryblium became superabundant at the site of Waipara in New Zealand during the early and middle EECO, reflecting the occurrence of significant stratification of surficial waters as well as increased salinity.[33]

Geologic effects

The EECO caused an increase in chert deposition by way of basin–basin fractionation by deep-sea circulation, causing increased silica concentrations in the North Atlantic which in turn resulted in direct precipitation of silica as well as its absorption by clay minerals.[34]

Comparison to present global warming

Because the pCO2 values of the EECO could potentially be reached if anthropogenic greenhouse gas emissions continue unabated for three centuries, the EECO has been used as an analogue for high-end projections of the Earth's future climate that would result from humanity's burning of fossil fuels.[35] Based on the Representative Concentration Pathway 8.5 (RCP8.5) emission scenario, by 2150 CE, the climates across much of the world would resemble conditions during the EECO.[36]

See also

References

  1. ^ a b c Scotese, Christopher R.; Song, Haijun; Mills, Benjamin J.W.; van der Meer, Douwe G. (1 April 2021). "Phanerozoic paleotemperatures: The earth's changing climate during the last 540 million years". Earth-Science Reviews. 215: 103503. Bibcode:2021ESRv..21503503S. doi:10.1016/j.earscirev.2021.103503. S2CID 233579194. Retrieved 24 December 2023 – via Elsevier Science Direct.
  2. ^ a b c Woodburne, Michael O.; Gunnell, Gregg F.; Stucky, Richard K. (11 August 2009). "Climate directly influences Eocene mammal faunal dynamics in North America". Proceedings of the National Academy of Sciences of the United States of America. 106 (32): 13399–13403. Bibcode:2009PNAS..10613399W. doi:10.1073/pnas.0906802106. ISSN 0027-8424. PMC 2726358. PMID 19666605.
  3. ^ Slotnick, B. S.; Dickens, G. R.; Hollis, C. J.; Crampton, J. S.; Strong, C. Percy; Phillips, A. (17 September 2015). "The onset of the Early Eocene Climatic Optimum at Branch Stream, Clarence River valley, New Zealand". New Zealand Journal of Geology and Geophysics. 58 (3): 262–280. Bibcode:2015NZJGG..58..262S. doi:10.1080/00288306.2015.1063514. S2CID 130982094.
  4. ^ Inglis, Gordon N.; Bragg, Fran; Burls, Natalie J.; Cramwinckel, Margot J.; Evans, David; Foster, Gavin L.; Huber, Matthew; Lunt, Daniel J.; Siler, Nicholas; Steinig, Sebastian; Tierney, Jessica E.; Wilkinson, Richard; Anagnostou, Eleni; de Boer, Agatha M.; Dunkley Jones, Tom; Edgar, Kirsty M.; Hollis, Christopher J.; Hutchinson, David K.; Pancost, Richard D. (26 October 2020). "Global mean surface temperature and climate sensitivity of the early Eocene Climatic Optimum (EECO), Paleocene–Eocene Thermal Maximum (PETM), and latest Paleocene". Climate of the Past. 16 (5): 1953–1968. Bibcode:2020CliPa..16.1953I. doi:10.5194/cp-16-1953-2020. hdl:1983/24a30f12-51a6-4544-9db8-b2009e33c02a. ISSN 1814-9332. Retrieved 24 December 2023.
  5. ^ Sloan, L.Cirbus; Morrill, C (15 November 1998). "Orbital forcing and Eocene continental temperatures". Palaeogeography, Palaeoclimatology, Palaeoecology. 144 (1–2): 21–35. Bibcode:1998PPP...144...21S. doi:10.1016/S0031-0182(98)00091-1. Retrieved 24 December 2023 – via Elsevier Science Direct.
  6. ^ Mathewes, Rolf W.; Greenwood, David R.; Archibald, S. Bruce (14 April 2016). Pigg, Kathleen B. (ed.). "Paleoenvironment of the Quilchena flora, British Columbia, during the Early Eocene Climatic Optimum". Canadian Journal of Earth Sciences. 53 (6): 574–590. Bibcode:2016CaJES..53..574M. doi:10.1139/cjes-2015-0163. hdl:1807/71979. ISSN 0008-4077. Retrieved 5 July 2024 – via Canadian Science Publishing.
  7. ^ Hyland, Ethan G.; Huntington, Katharine W.; Sheldon, Nathan D.; Reichgelt, Tammo (4 October 2018). "Temperature seasonality in the North American continental interior during the Early Eocene Climatic Optimum". Climate of the Past. 14 (10): 1391–1404. Bibcode:2018CliPa..14.1391H. doi:10.5194/cp-14-1391-2018. hdl:2027.42/148644. ISSN 1814-9332. Retrieved 3 February 2024.
  8. ^ Broz, Adrian P.; Pritchard-Peterson, Devin; Spinola, Diogo; Schneider, Sarah; Retallack, Gregory; Silva, Lucas C. R. (31 January 2024). "Eocene (50–55 Ma) greenhouse climate recorded in nonmarine rocks of San Diego, CA, USA". Scientific Reports. 14 (1): 2613. Bibcode:2024NatSR..14.2613B. doi:10.1038/s41598-024-53210-0. ISSN 2045-2322. PMC 10830502. PMID 38297060.
  9. ^ Ivany, L. C.; Lohmann, K. C.; Hasiuk, F.; Blake, D. B.; Glass, A.; Aronson, R. B.; Moody, R. M. (1 May 2008). "Eocene climate record of a high southern latitude continental shelf: Seymour Island, Antarctica". Geological Society of America Bulletin. 120 (5–6): 659–678. Bibcode:2008GSAB..120..659I. doi:10.1130/B26269.1. ISSN 0016-7606 – via GeoScienceWorld.
  10. ^ Kad, Pratik; Blau, Manuel Tobias; Ha, Kyung-Ja; Zhu, Jiang (1 November 2022). "Elevation-dependent temperature response in early Eocene using paleoclimate model experiment". Environmental Research Letters. 17 (11): 114038. Bibcode:2022ERL....17k4038K. doi:10.1088/1748-9326/ac9c74. ISSN 1748-9326.
  11. ^ Lunt, Daniel J.; Bragg, Fran; Chan, Wing-Le; Hutchinson, David K.; Ladant, Jean-Baptiste; Morozova, Polina; Niezgodzki, Igor; Steinig, Sebastian; Zhang, Zhongshi; Zhu, Jiang; Abe-Ouchi, Ayako; Anagnostou, Eleni; de Boer, Agatha M.; Coxall, Helen K.; Donnadieu, Yannick; Foster, Gavin; Inglis, Gordon N.; Knorr, Gregor; Langebroek, Petra M.; Lear, Caroline H.; Lohmann, Gerrit; Poulsen, Christopher J.; Sepulchre, Pierre; Tierney, Jessica E.; Valdes, Paul J.; Volodin, Evgeny M.; Jones, Tom Dunkley; Hollis, Christopher J.; Huber, Matthew; Otto-Bliesner, Bette L. (15 January 2021). "DeepMIP: model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data". Climate of the Past. 17 (1): 203–227. Bibcode:2021CliPa..17..203L. doi:10.5194/cp-17-203-2021. ISSN 1814-9332. Retrieved 25 June 2024.
  12. ^ Bernard, S.; Daval, D.; Ackerer, P.; Pont, S.; Meibom, A. (26 October 2017). "Burial-induced oxygen-isotope re-equilibration of fossil foraminifera explains ocean paleotemperature paradoxes". Nature Communications. 8 (1): 1134. Bibcode:2017NatCo...8.1134B. doi:10.1038/s41467-017-01225-9. ISSN 2041-1723. PMC 5656689. PMID 29070888.
  13. ^ Goudsmit-Harzevoort, Barbara; Lansu, Angelique; Baatsen, Michiel L. J.; von der Heydt, Anna S.; de Winter, Niels J.; Zhang, Yurui; Abe-Ouchi, Ayako; de Boer, Agatha; Chan, Wing-Le; Donnadieu, Yannick; Hutchinson, David K.; Knorr, Gregor; Ladant, Jean-Baptiste; Morozova, Polina; Niezgodzki, Igor; Steinig, Sebastian; Tripati, Aradhna; Zhang, Zhongshi; Zhu, Jiang; Ziegler, Martin (17 February 2023). "The Relationship Between the Global Mean Deep-Sea and Surface Temperature During the Early Eocene". Paleoceanography and Paleoclimatology. 38 (3): 1–18. Bibcode:2023PaPa...38.4532G. doi:10.1029/2022PA004532. ISSN 2572-4517.
  14. ^ Pearson, Paul N.; Palmer, Martin R. (17 August 2000). "Atmospheric carbon dioxide concentrations over the past 60 million years". Nature. 406 (6797): 695–699. Bibcode:2000Natur.406..695P. doi:10.1038/35021000. ISSN 1476-4687. PMID 10963587. S2CID 205008176. Retrieved 24 December 2023.
  15. ^ Smith, Robin Y.; Greenwood, David R.; Basinger, James F. (1 July 2010). "Estimating paleoatmospheric pCO2 during the Early Eocene Climatic Optimum from stomatal frequency of Ginkgo, Okanagan Highlands, British Columbia, Canada". Palaeogeography, Palaeoclimatology, Palaeoecology. 293 (1–2): 120–131. Bibcode:2010PPP...293..120S. doi:10.1016/j.palaeo.2010.05.006. Retrieved 25 June 2024 – via Elsevier Science Direct.
  16. ^ Sloan, L. Cirbus; Walker, James C. G.; Moore, T. C.; Rea, David K.; Zachos, James C. (28 May 1992). "Possible methane-induced polar warming in the early Eocene". Nature. 357 (6376): 320–322. Bibcode:1992Natur.357..320S. doi:10.1038/357320a0. hdl:2027.42/62963. ISSN 0028-0836. PMID 11536496. S2CID 4348331. Retrieved 24 December 2023.
  17. ^ Riegel, Walter; Wilde, Volker (1 April 2016). "An early Eocene Sphagnum bog at Schöningen, northern Germany". International Journal of Coal Geology. 159: 57–70. Bibcode:2016IJCG..159...57R. doi:10.1016/j.coal.2016.03.021. Retrieved 25 June 2024 – via Elsevier Science Direct.
  18. ^ Elson, Amy L.; Rohrssen, Megan; Marshall, John; Inglis, Gordon N.; Whiteside, Jessica H. (1 June 2022). "Hydroclimate variability in the United States continental interior during the early Eocene Climatic Optimum". Palaeogeography, Palaeoclimatology, Palaeoecology. 595: 110959. Bibcode:2022PPP...59510959E. doi:10.1016/j.palaeo.2022.110959. Retrieved 25 June 2024 – via Elsevier Science Direct.
  19. ^ Zachos, James; Pagani, Mark; Sloan, Lisa; Thomas, Ellen; Billups, Katharina (27 April 2001). "Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present". Science. 292 (5517): 686–693. Bibcode:2001Sci...292..686Z. doi:10.1126/science.1059412. ISSN 0036-8075. PMID 11326091. S2CID 2365991. Retrieved 24 December 2023.
  20. ^ Lauretano, V.; Littler, K.; Polling, M.; Zachos, J. C.; Lourens, L. J. (7 October 2015). "Frequency, magnitude and character of hyperthermal events at the onset of the Early Eocene Climatic Optimum". Climate of the Past. 11 (10): 1313–1324. Bibcode:2015CliPa..11.1313L. doi:10.5194/cp-11-1313-2015. ISSN 1814-9332. Retrieved 24 December 2023.
  21. ^ Zhang, Shao-Hua; Ji, Wei-Qiang; Chen, Hou-Bin; Kirstein, Linda A.; Wu, Fu-Yuan (June 2023). "Linking rapid eruption of the Linzizong volcanic rocks and Early Eocene Climatic Optimum (EECO): Constraints from the Pana Formation in the Linzhou and Pangduo basins, southern Tibet". Lithos. 446–447: 107159. Bibcode:2023Litho.44607159Z. doi:10.1016/j.lithos.2023.107159. hdl:20.500.11820/5605da8a-33fd-42ee-8d54-68590a4e12f8. S2CID 257848801. Retrieved 24 December 2023 – via Elsevier Science Direct.
  22. ^ Hyland, E.; Sheldon, N. D.; Fan, M. (1 July 2013). "Terrestrial paleoenvironmental reconstructions indicate transient peak warming during the early Eocene climatic optimum". Geological Society of America Bulletin. 125 (7–8): 1338–1348. Bibcode:2013GSAB..125.1338H. doi:10.1130/B30761.1. ISSN 0016-7606. Retrieved 5 July 2024 – via GeoScienceWorld.
  23. ^ Benton, Michael James; Wilf, Peter; Sauquet, Hervé (26 October 2021). "The Angiosperm Terrestrial Revolution and the origins of modern biodiversity". New Phytologist. 233 (5): 2017–2035. doi:10.1111/nph.17822. hdl:1983/82a09075-31f4-423e-98b9-3bb2c215e04b. PMID 34699613. S2CID 240000207. Retrieved 24 November 2022.
  24. ^ Heinrichs, Jochen; Scheben, Armin; Bechteler, Julia; Lee, Gaik Ee; Schäfer-Verwimp, Alfons; Hedenäs, Lars; Singh, Hukam; Pócs, Tamás; Nascimbene, Paul C.; Peralta, Denilson F.; Renner, Matt; Schmidt, Alexander R. (31 May 2016). Wong, William Oki (ed.). "Crown Group Lejeuneaceae and Pleurocarpous Mosses in Early Eocene (Ypresian) Indian Amber". PLOS ONE. 11 (5): e0156301. Bibcode:2016PLoSO..1156301H. doi:10.1371/journal.pone.0156301. ISSN 1932-6203. PMC 4887038. PMID 27244582.
  25. ^ Smith, Robin Y.; Basinger, James F.; Greenwood, David R. (21 October 2011). "Early Eocene plant diversity and dynamics in the Falkland flora, Okanagan Highlands, British Columbia, Canada". Palaeobiodiversity and Palaeoenvironments. 92 (3): 309–328. doi:10.1007/s12549-011-0061-5. ISSN 1867-1594. Retrieved 25 June 2024 – via Springer Link.
  26. ^ Archibald, S. Bruce; Morse, Geoffrey E.; Greenwood, David R.; Mathewes, Rolf W. (12 May 2014). "Fossil palm beetles refine upland winter temperatures in the Early Eocene Climatic Optimum". Proceedings of the National Academy of Sciences of the United States of America. 111 (22): 8095–8100. Bibcode:2014PNAS..111.8095A. doi:10.1073/pnas.1323269111. ISSN 0027-8424. PMC 4050627. PMID 24821798.
  27. ^ Miller, Kristen; Tietjen, Kristen; Beard, K. Christopher (25 January 2023). Meloro, Carlo (ed.). "Basal Primatomorpha colonized Ellesmere Island (Arctic Canada) during the hyperthermal conditions of the early Eocene climatic optimum". PLOS ONE. 18 (1): e0280114. Bibcode:2023PLoSO..1880114M. doi:10.1371/journal.pone.0280114. ISSN 1932-6203. PMC 9876366. PMID 36696373.
  28. ^ Bondarenko, Olesya V.; Utescher, Torsten (19 May 2022). "Late early to early middle Eocene climate and vegetation change at Tastakh Lake (northern Yakutia, eastern Siberia)". Palaeobiodiversity and Palaeoenvironments. 103 (2): 277–301. doi:10.1007/s12549-022-00530-6. ISSN 1867-1594. Retrieved 5 July 2024 – via Springer Link.
  29. ^ Zhou, Xinying; Wang, Jian; Li, Qian; Bai, Bin; Mao, Fangyuan; Li, Xiaoqiang; Wang, Yuan-Qing (29 June 2023). "Late Paleocene to early Oligocene fire ecology of the south Mongolian highland". Frontiers in Earth Science. 11. Bibcode:2023FrEaS..1171452Z. doi:10.3389/feart.2023.1171452. ISSN 2296-6463.
  30. ^ Woodburne, Michael O.; Goin, Francisco J.; Raigemborn, Maria Sol; Heizler, Matt; Gelfo, Javier N.; Oliveira, Edison V. (October 2014). "Revised timing of the South American early Paleogene land mammal ages". Journal of South American Earth Sciences. 54: 109–119. Bibcode:2014JSAES..54..109W. doi:10.1016/j.jsames.2014.05.003. hdl:11336/79162. Retrieved 3 February 2024 – via Elsevier Science Direct.
  31. ^ Fernicola, Juan Carlos; Zimicz, Ana N.; Chornogubsky, Laura; Ducea, Mihai; Cruz, Laura E.; Bond, Mariano; Arnal, Michelle; Cárdenas, Magalí; Fernández, Mercedes (10 May 2021). "The Early Eocene Climatic Optimum at the Lower Section of the Lumbrera Formation (Ypresian, Salta Province, Northwestern Argentina): Origin and Early Diversification of the Cingulata". Journal of Mammalian Evolution. 28 (3): 621–633. doi:10.1007/s10914-021-09545-w. ISSN 1064-7554. S2CID 236602601. Retrieved 3 February 2024 – via Springer.
  32. ^ McGowran, Brian; Hill, Robert S. (9 June 2015). "Cenozoic climatic shifts in southern Australia". Transactions of the Royal Society of South Australia. 139 (1): 19–37. Bibcode:2015TRSAu.139...19M. doi:10.1080/03721426.2015.1035215. ISSN 0372-1426. Retrieved 5 July 2024 – via Taylor and Francis Online.
  33. ^ Crouch, E. M.; Shepherd, C. L.; Morgans, H. E. G.; Naafs, B. D. A.; Dallanave, E.; Phillips, A.; Hollis, C. J.; Pancost, R. D. (1 January 2020). "Climatic and environmental changes across the early Eocene climatic optimum at mid-Waipara River, Canterbury Basin, New Zealand". Earth-Science Reviews. 200: 102961. Bibcode:2020ESRv..20002961C. doi:10.1016/j.earscirev.2019.102961. hdl:1983/aedc04cc-bba8-44c6-8f9d-ba398bb24607. ISSN 0012-8252. S2CID 210618370. Retrieved 11 September 2023.
  34. ^ Muttoni, Giovanni; Kent, Dennis V. (27 September 2007). "Widespread formation of cherts during the early Eocene climate optimum". Palaeogeography, Palaeoclimatology, Palaeoecology. 253 (3–4): 348–362. Bibcode:2007PPP...253..348M. doi:10.1016/j.palaeo.2007.06.008. Retrieved 25 June 2024 – via Elsevier Science Direct.
  35. ^ Zachos, James C.; Dickens, Gerald R.; Zeebe, Richard E. (16 January 2008). "An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics". Nature. 451 (7176): 279–283. Bibcode:2008Natur.451..279Z. doi:10.1038/nature06588. ISSN 1476-4687. PMID 18202643.
  36. ^ Burke, K. D.; Williams, J. W.; Chandler, M. A.; Haywood, A. M.; Lunt, D. J.; Otto-Bliesner, B. L. (26 December 2018). "Pliocene and Eocene provide best analogs for near-future climates". Proceedings of the National Academy of Sciences of the United States of America. 115 (52): 13288–13293. Bibcode:2018PNAS..11513288B. doi:10.1073/pnas.1809600115. ISSN 0027-8424. PMC 6310841. PMID 30530685.
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