Carbon sequestration during the Palaeocene-Eocene Thermal Maximum by an efficient biological pump

Zhongwu Ma, Ellen Gray, Ellen Thomas, Brandon Murphy, James Zachos, Adina Paytan

Research output: Contribution to journalArticlepeer-review

98 Scopus citations

Abstract

A perturbation of the carbon cycle and biosphere, linked to globally increased temperatures about 55.9 million years ago, characterized the Palaeocene-Eocene Thermal Maximum. Its effect on global oceanic productivity is controversial. Here we present records of marine barite accumulation rates that show distinct peaks during this time interval, suggesting a general increase in export productivity. We propose that changes in marine ecosystems, resulting from high atmospheric partial pressure of CO2 and ocean acidification, led to enhanced carbon export from the photic zone to depth, thereby increasing the efficiency of the biological pump. Higher seawater temperatures at that time increased bacterial activity and organic matter regeneration. Through this process much of the sinking particulate organic matter was probably converted to dissolved inorganic and organic carbon. We estimate that an annual carbon export flux out of the euphotic zone and into the deep ocean waters could have amounted to about 15 Gt during the Palaeocene-Eocene Thermal Maximum. About 0.4% of this carbon is expected to have entered the refractory dissolved organic pool, where it could be sequestered from the atmosphere for tens of thousands of years. Our estimates are consistent with the amount of carbon redistribution expected for the recovery from the Palaeocene-Eocene Thermal Maximum.

Original languageEnglish
Pages (from-to)382-388
Number of pages7
JournalNature Geoscience
Volume7
Issue number5
DOIs
StatePublished - 1 Jan 2014
Externally publishedYes

ASJC Scopus subject areas

  • General Earth and Planetary Sciences

Fingerprint

Dive into the research topics of 'Carbon sequestration during the Palaeocene-Eocene Thermal Maximum by an efficient biological pump'. Together they form a unique fingerprint.

Cite this