Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events
Multiple short-lived global warming events, known as hyperthermals, occurred during the early Eocene (56–52 Ma). Five of these events – the Paleocene–Eocene Thermal Maximum (PETM or ETM1), H1 (or ETM2), H2, I1, and I2 – are marked by a carbon isotope excursion (CIE) within both marine and terrestria...
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ftmontclairstuni:oai:digitalcommons.montclair.edu:earth-environ-studies-facpubs-1169 2023-07-23T04:20:17+02:00 Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events Cui, Ying Schubert, Brian A. 2017-11-15T08:00:00Z application/pdf https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/170 https://doi.org/10.1016/j.epsl.2017.08.038 https://digitalcommons.montclair.edu/context/earth-environ-studies-facpubs/article/1169/viewcontent/Atmospheric.pdf unknown Montclair State University Digital Commons https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/170 doi:10.1016/j.epsl.2017.08.038 https://digitalcommons.montclair.edu/context/earth-environ-studies-facpubs/article/1169/viewcontent/Atmospheric.pdf Department of Earth and Environmental Studies Faculty Scholarship and Creative Works C land plant proxy early Eocene hyperthermals pCO Earth Sciences Environmental Sciences text 2017 ftmontclairstuni https://doi.org/10.1016/j.epsl.2017.08.038 2023-07-03T21:53:28Z Multiple short-lived global warming events, known as hyperthermals, occurred during the early Eocene (56–52 Ma). Five of these events – the Paleocene–Eocene Thermal Maximum (PETM or ETM1), H1 (or ETM2), H2, I1, and I2 – are marked by a carbon isotope excursion (CIE) within both marine and terrestrial sediments. The magnitude of CIE, which is a function of the amount and isotopic composition of carbon added to the ocean–atmosphere system, varies significantly between marine versus terrestrial substrates. Here we use the increase in carbon isotope fractionation by C3 land plants in response to increased pCO2 to reconcile this difference and reconstruct a range of background pCO2 and peak pCO2 for each CIE, provided two potential carbon sources: methane hydrate destabilization and permafrost-thawing/organic matter oxidation. Although the uncertainty on each pCO2 estimate using this approach is low (e.g., median uncertainty = +23%/−18%), this work highlights the potential for significant systematic bias in the pCO2 estimate resulting from sampling resolution, substrate type, diagenesis, and environmental change. Careful consideration of each of these factors is required especially when applying this approach to a single marine–terrestrial CIE pair. Given these limitations, we provide an upper estimate for background early Eocene pCO2 of 463 +248/−131 ppmv (methane hydrate scenario) to 806 +127/−104 ppmv (permafrost-thawing/organic matter oxidation scenario). These results, which represent the first pCO2 proxy estimates directly tied to the Eocene hyperthermals, demonstrate that early Eocene warmth was supported by background pCO2 less than ∼3.5× preindustrial levels and that pCO2>1000 ppmv may have occurred only briefly, during hyperthermal events. Text Methane hydrate permafrost Montclair State University Digital Commons Earth and Planetary Science Letters 478 225 233 |
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Montclair State University Digital Commons |
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C land plant proxy early Eocene hyperthermals pCO Earth Sciences Environmental Sciences |
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C land plant proxy early Eocene hyperthermals pCO Earth Sciences Environmental Sciences Cui, Ying Schubert, Brian A. Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
topic_facet |
C land plant proxy early Eocene hyperthermals pCO Earth Sciences Environmental Sciences |
description |
Multiple short-lived global warming events, known as hyperthermals, occurred during the early Eocene (56–52 Ma). Five of these events – the Paleocene–Eocene Thermal Maximum (PETM or ETM1), H1 (or ETM2), H2, I1, and I2 – are marked by a carbon isotope excursion (CIE) within both marine and terrestrial sediments. The magnitude of CIE, which is a function of the amount and isotopic composition of carbon added to the ocean–atmosphere system, varies significantly between marine versus terrestrial substrates. Here we use the increase in carbon isotope fractionation by C3 land plants in response to increased pCO2 to reconcile this difference and reconstruct a range of background pCO2 and peak pCO2 for each CIE, provided two potential carbon sources: methane hydrate destabilization and permafrost-thawing/organic matter oxidation. Although the uncertainty on each pCO2 estimate using this approach is low (e.g., median uncertainty = +23%/−18%), this work highlights the potential for significant systematic bias in the pCO2 estimate resulting from sampling resolution, substrate type, diagenesis, and environmental change. Careful consideration of each of these factors is required especially when applying this approach to a single marine–terrestrial CIE pair. Given these limitations, we provide an upper estimate for background early Eocene pCO2 of 463 +248/−131 ppmv (methane hydrate scenario) to 806 +127/−104 ppmv (permafrost-thawing/organic matter oxidation scenario). These results, which represent the first pCO2 proxy estimates directly tied to the Eocene hyperthermals, demonstrate that early Eocene warmth was supported by background pCO2 less than ∼3.5× preindustrial levels and that pCO2>1000 ppmv may have occurred only briefly, during hyperthermal events. |
format |
Text |
author |
Cui, Ying Schubert, Brian A. |
author_facet |
Cui, Ying Schubert, Brian A. |
author_sort |
Cui, Ying |
title |
Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
title_short |
Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
title_full |
Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
title_fullStr |
Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
title_full_unstemmed |
Atmospheric pCO2 Reconstructed Across Five Early Eocene Global Warming Events |
title_sort |
atmospheric pco2 reconstructed across five early eocene global warming events |
publisher |
Montclair State University Digital Commons |
publishDate |
2017 |
url |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/170 https://doi.org/10.1016/j.epsl.2017.08.038 https://digitalcommons.montclair.edu/context/earth-environ-studies-facpubs/article/1169/viewcontent/Atmospheric.pdf |
genre |
Methane hydrate permafrost |
genre_facet |
Methane hydrate permafrost |
op_source |
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works |
op_relation |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/170 doi:10.1016/j.epsl.2017.08.038 https://digitalcommons.montclair.edu/context/earth-environ-studies-facpubs/article/1169/viewcontent/Atmospheric.pdf |
op_doi |
https://doi.org/10.1016/j.epsl.2017.08.038 |
container_title |
Earth and Planetary Science Letters |
container_volume |
478 |
container_start_page |
225 |
op_container_end_page |
233 |
_version_ |
1772184200997240832 |