气候变化领域集成服务门户(CCPortal): The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons

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DOI	10.5194/cp-17-269-2021
	The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons
	Hutchinson D.K.; Coxall H.K.; Lunt D.J.; Steinthorsdottir M.; De Boer A.M.; Baatsen M.; Von Der Heydt A.; Huber M.; Kennedy-Asser A.T.; Kunzmann L.; Ladant J.-B.; Lear C.H.; Moraweck K.; Pearson P.N.; Piga E.; Pound M.J.; Salzmann U.; Scher H.D.; Sijp W.P.; Å liwińska K.K.; Wilson P.A.; Zhang Z.
发表日期	2021
ISSN	1814-9324
起始页码	245
结束页码	263
卷号	17 期号:1
英文摘要	The Eocene-Oligocene transition (EOT) was a climate shift from a largely ice-free greenhouse world to an icehouse climate, involving the first major glaciation of Antarctica and global cooling occurring ∼ 34 million years ago (Ma) and lasting ∼ 790 kyr. The change is marked by a global shift in deep-sea δ18O representing a combination of deep-ocean cooling and growth in land ice volume. At the same time, multiple independent proxies for ocean temperature indicate sea surface cooling, and major changes in global fauna and flora record a shift toward more cold-climateadapted species. The two principal suggested explanations of this transition are a decline in atmospheric CO2 and changes to ocean gateways, while orbital forcing likely influenced the precise timing of the glaciation. Here we review and synthesise proxy evidence of palaeogeography, temperature, ice sheets, ocean circulation and CO2 change from the marine and terrestrial realms. Furthermore, we quantitatively compare proxy records of change to an ensemble of climate model simulations of temperature change across the EOT. The simulations compare three forcing mechanisms across the EOT: CO2 decrease, palaeogeographic changes and ice sheet growth. Our model ensemble results demonstrate the need for a global cooling mechanism beyond the imposition of an ice sheet or palaeogeographic changes. We find that CO2 forcing involving a large decrease in CO2 of ca. 40 % (∼ 325 ppm drop) provides the best fit to the available proxy evidence, with ice sheet and palaeogeographic changes playing a secondary role. While this large decrease is consistent with some CO2 proxy records (the extreme endmember of decrease), the positive feedback mechanisms on ice growth are so strong that a modest CO2 decrease beyond a critical threshold for ice sheet initiation is well capable of triggering rapid ice sheet growth. Thus, the amplitude of CO2 decrease signalled by our data-model comparison should be considered an upper estimate and perhaps artificially large, not least because the current generation of climate models do not include dynamic ice sheets and in some cases may be undersensitive to CO2 forcing. The model ensemble also cannot exclude the possibility that palaeogeographic changes could have triggered a reduction in CO2. © 2021 Author(s).
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183611
作者单位	Department of Geological Sciences, Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden; School of Geographical Sciences, University of Bristol, Bristol, United Kingdom; Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden; Institute for Marine and Atmospheric Research, Department of Physics, Utrecht University, Utrecht, Netherlands; Centre for Complex Systems Studies, Utrecht University, Utrecht, Netherlands; Department of Earth Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, United States; Senckenberg Natural History Collections, Dresden, Germany; Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, United States; School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom; Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom; School of the Earth Ocean and Environment, University of South Carolina, Columbia, SC, United Sta...
推荐引用方式 GB/T 7714	Hutchinson D.K.,Coxall H.K.,Lunt D.J.,et al. The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons[J],2021,17(1).
APA	Hutchinson D.K..,Coxall H.K..,Lunt D.J..,Steinthorsdottir M..,De Boer A.M..,...&Zhang Z..(2021).The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons.Climate of the Past,17(1).
MLA	Hutchinson D.K.,et al."The Eocene-Oligocene transition: A review of marine and terrestrial proxy data, models and model-data comparisons".Climate of the Past 17.1(2021).