Dynamics of the Earth System In REcovery (DESIRE)

• Applicant: Dr. Sandra Arndt
• Subject Area: Palaeontology
• Term: Funded in 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 195029283

The Earth system has two possible modes of ‘recovery’ through which it can permanently remove carbon dioxide from the atmosphere and hence cool the climate: burial of carbon in form of a) carbonates and/or b) organic matter. The very efficient, organic carbon burial mode of recovery, even though of central importance at times in the past, is still not well understood. A number of possible factors can act to increase the efficiency and rate of organic carbon burial. Recently, it has also been suggested that the presence of free hydrogen sulfide under euxinic conditions may be critical in enhancing organic matter preservation, as cross-linking organic molecules with sulfur (sulfurization or ‘vulcanization’) greatly increases the recalcitrance of the organic matter. Hence, sulfurization could be an important emergency recovery mechanism within the Earth System. We propose to assess and compare the significance of this mechanism in the recovery of the Earth System from the Paleocene- Eocene Thermal Maximum (‘PETM’, ca. 55 million years ago (Ma)) and the Toarcian Oceanic Anoxic Event (OAE, ca. 183 Ma). For this purpose, we will design a novel, fully coupled, but very efficient Earth system model that will integrate an efficient representation of organic carbon preservation and burial, applicable to oxic-through-euxinic conditions in the framework of a global carbon cycle and climate model. By doing so, we will for the first time quantitatively interpret the recovery of the Earth system from a perturbation of the global carbon cycle and the associated global warming.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Host: Professor Dr. Andy Ridgwell