The Role of Carbon Dioxide During the Onset of Antarctic Glaciation

  title={The Role of Carbon Dioxide During the Onset of Antarctic Glaciation},
  author={Mark Pagani and Matthew Huber and Zhonghui Liu and Steven M. Bohaty and Jorijntje Henderiks and Willem P. Sijp and Srinath Krishnan and Robert M. DeConto},
  pages={1261 - 1264}
Antarctica glaciation began soon after a large decrease in the concentration of atmospheric carbon dioxide around 35 million years ago. Earth’s modern climate, characterized by polar ice sheets and large equator-to-pole temperature gradients, is rooted in environmental changes that promoted Antarctic glaciation ~33.7 million years ago. Onset of Antarctic glaciation reflects a critical tipping point for Earth’s climate and provides a framework for investigating the role of atmospheric carbon… 
Deciphering the role of southern gateways and carbon dioxide on the onset of the Antarctic Circumpolar Current
[1] Growth of Antarctic ice sheet during the Cenozoic 34 million years ago appears as a potential tipping point in the long term cooling trend that began 50 Ma ago. For decades, the onset of the
Palaeoclimate science: Causes and effects of Antarctic ice
  • D. Lunt
  • Environmental Science, Geography
  • 2014
A climate model is used to show that the growth of the ice sheet — forced by changes in CO2 — drove the changes in ocean circulation, in contrast to the opening of the gateways, which had relatively little impact on ocean circulation.
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It is shown that the Antarctic glaciation at the Eocene−Oligocene boundary was preceded by a period of heat accumulation in the low latitudes, likely focused in a progressively contracting South Atlantic gyre, which contributed to cooling high-latitude austral regions.
Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate
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Antarctic glaciation caused ocean circulation changes at the Eocene–Oligocene transition
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Uncertainties in the Modelled CO2 Threshold for Antarctic Glaciation
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Atmospheric CO2 reconstructions ranged between 500 and 300ppm across intervals of significant climate and environmental change from the late Oligocene to the Pliocene, indicating that major climate
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Antarctic climate changes have been reconstructed from ice and sediment cores and numerical models (which also predict future changes). Major ice sheets first appeared 34 million years ago (Ma) and


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In this simulation, declining Cenozoic CO2 first leads to the formation of small, highly dynamic ice caps on high Antarctic plateaux, and at a later time, a CO2 threshold is crossed, initiating ice-sheet height/mass-balance feedbacks that cause the ice caps to expand rapidly with large orbital variations, eventually coalescing into a continental-scale East Antarctic Ice Sheet.
Atmospheric carbon dioxide through the Eocene–Oligocene climate transition
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Northern high-latitude terrestrial climate estimates for the Eocene to Oligocene interval, based on bioclimatic analysis of terrestrially derived spore and pollen assemblages preserved in marine sediments from the Norwegian–Greenland Sea indicate a cooling of ∼5 °C in cold-month (winter) mean temperatures to 0–2‬C, and a concomitant increased seasonality before the Oi-1 glaciation event.
Thresholds for Cenozoic bipolar glaciation
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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
Marked Decline in Atmospheric Carbon Dioxide Concentrations During the Paleogene
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.
Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean
The changes in oxygen-isotope composition across the Eocene/Oligocene boundary are too large to be explained by Antarctic ice-sheet growth alone and must therefore also indicate contemporaneous global cooling and/or Northern Hemisphere glaciation.
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[1] Near the Eocene's close (∼34 million years ago), the climate system underwent one of the largest shifts in Earth's history: Antarctic terrestrial ice sheets suddenly grew and ocean productivity
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Deep-sea drilling in the Antarctic region (Deep-Sea Drilling Project legs 28, 29, 35, and 36) has provided many new data about the development of circum-Antarctic circulation and the closely related
Transient Middle Eocene Atmospheric CO2 and Temperature Variations
It appears that vast amounts of CO2 were injected into the atmosphere, and a sea surface temperature increase of as much a 6°C accompanied the atmospheric CO2 rise, suggesting that elevated pCO2 played a major role in global warming during the MECO.