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Durham University

Institute of Medieval and Early Modern Studies (IMEMS)

Staff and Governance

Core Staff

The day-to-day running of IMEMS is the responsibility of the Core Executive Committee, comprising the Director and Associate Directors and the Administrator. 

Publication details for Prof. James Baldini

Baldini, James U.L., Bertram, Rachel A. & Ridley, Harriet E. (2018). Ground air: A first approximation of the Earth's second largest reservoir of carbon dioxide gas. Science of the Total Environment 616-617: 1007-1013.

Author(s) from Durham


It is becoming increasingly clear that a substantial reservoir of carbon exists in the unsaturated zone of aquifers, though the total size of this reservoir on a global scale remains unquantified. Here we provide the first broad estimate of the amount of carbon dioxide gas found in this terrestrial reservoir. We calculate that between 2 and 53 PgC exists as gaseous CO2 in aquifers worldwide, generated by the slow microbial oxidation of organic particles transported into aquifers by percolating groundwater. Importantly, this carbon reservoir is in the form of CO2 gas, and is therefore transferable to the Earth's atmosphere without any phase change. On a coarse scale, water table depths are partially controlled by local sea level; sea level lowering therefore allows slow carbon sequestration into the reservoir and sea level increases force rapid CO2 outgassing from this reservoir. High-resolution cave air pCO2 data demonstrate that sea level variability does affect CO2 outgassing rates from the unsaturated zone, and that the CO2 outgassing due to sea level rise currently occurs on daily (tidal) timescales. We suggest that global mean water table depth must modulate the global unsaturated zone volume and the size of this carbon reservoir, potentially affecting atmospheric CO2 on geological timescales.

Full Executive Committee

Our Full Executive Committee is made up of the Core Executive Committee, listed above, plus a number of executive members including:

International Advisory Board

We are extremely fortunate to have be able to call on the help and guidance of colleagues from around the world who help to shape and guide our direction, strategy and international reach. Our current Advisory Board members are: