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Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present
This work focuses primarily on the periodic and anomalous components of variability over the early portion of this era, as constrained by the latest generation of deep-sea isotope records.
Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene
- M. Pagani, J. Zachos, K. Freeman, B. Tipple, S. Bohaty
- Environmental Science, GeographyScience
- 22 July 2005
Stable carbon isotopic values of di-unsaturated alkenones extracted from deep sea cores are used to reconstruct pCO2 from the middle Eocene to the late Oligocene and demonstrate that it ranged between 1000 to 1500 parts per million by volume in the middle to late Eocene, then decreased in several steps during theOligocene, and reached modern levels by the latest Oligaen.
Sea Level Change Through the Last Glacial Cycle
Changes: The Spatial and Evolutionary Responses of Terrestrial Biota, B. Huntley et al., Eds. (SpringerVerlag, Berlin, 1997), pp. 357–370. 46. B. Huntley, I. C. Prentice, in Global Climates Since the…
High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations
Earth-system climate sensitivity includes the effects of long-term feedbacks such as changes in continental ice-sheet extent and terrestrial ecosystems. A reconstruction of atmospheric carbon dioxide…
Global Cooling During the Eocene-Oligocene Climate Transition
About 34 million years ago, Earth's climate shifted from a relatively ice-free world to one with glacial conditions on Antarctica characterized by substantial ice sheets. How Earth's temperature…
Carbon isotope ratio of Cenozoic CO2: A comparative evaluation of available geochemical proxies
 The carbon isotope ratio (δ13C) of plant material is commonly used to reconstruct the relative distribution of C3 and C4 plants in ancient ecosystems. However, such estimates depend on the δ13C…
Miocene evolution of atmospheric carbon dioxide
Changes in pCO2 or ocean circulation are generally invoked to explain warm early Miocene climates and a rapid East Antarctic ice sheet (EAIS) expansion in the middle Miocene. This study reconstructs…
Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum
It is shown that sea surface temperatures near the North Pole increased from ∼18 °C to over 23°C during this event, which suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds or hurricane-induced ocean mixing—to amplify early Palaeogene polar temperatures.
Thresholds for Cenozoic bipolar glaciation
- R. DeConto, D. Pollard, P. Wilson, H. Pälike, C. Lear, M. Pagani
- Environmental Science, GeographyNature
- 2 October 2008
It is found that Oi-1 is best explained by Antarctic glaciation alone, combined with deep-sea cooling of up to 4 °C and Antarctic ice that is less isotopically depleted than previously suggested, which implies that episodic northern-hemispheric ice sheets have been possible some 20 million years earlier than currently assumed and could explain some of the variability in Miocene sea-level records.
A 40-million-year history of atmospheric CO2
- Yi Ge Zhang, M. Pagani, Zhonghui Liu, S. Bohaty, R. DeConto
- Environmental Science, GeographyPhilosophical Transactions of the Royal Society A…
- 28 October 2013
A pCO2 record spanning the past 40 million years from a single marine locality, Ocean Drilling Program Site 925 located in the western equatorial Atlantic Ocean, shows that in the Neogene with low CO2 levels, algal carbon concentrating mechanisms and spontaneous biocarbonate–CO2 conversions are likely to play a more important role inAlgal carbon fixation, which provides a potential bias to the alkenone–pCO2 method.