University of Exeter funding: NERC GW4+ DTP PhD studentship

Quantifying the contribution of enhanced carbonate weathering to Earth system resilience. PhD in Geography (NERC GW4+ DTP) Ref: 3687

About the award


Lead Supervisor

Prof Tim Lenton, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Additional Supervisors

Dr Ute Schuster, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Dr Paul Halloran, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Location: University of Exeter, Streatham Campus, Exeter EX4 4QJ

This project is one of a number that are in competition for funding from the NERC GW4+ Doctoral Training Partnership (GW4+ DTP).  The GW4+ DTP consists of the GW4 Alliance of research-intensive universities: the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five unique and prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory.  The partnership aims to provide a broad training in the Earth, Environmental and Life sciences, designed to train tomorrow’s leaders in scientific research, business, technology and policy-making. For further details about the programme please see

For eligible successful applicants, the studentships comprises:

  • A stipend for 3.5 years (currently £15,009 p.a. for 2019/20) in line with UK Research and Innovation rates
  • Payment of university tuition fees;
  • A research budget of £11,000 for an international conference, lab, field and research expenses;
  • A training budget of £3,250 for specialist training courses and expenses.
  • Travel and accomodation is covered for all compulsory DTP cohort events
  • No course fees for courses run by the DTP

We are currently advertising projects for a total of 10 studentships at the University of Exeter


Students who are resident in EU countries are eligible for the full award on the same basis as UK residents.  Applicants resident outside of the EU (classed as International for tuition fee purposes) are not eligible for DTP funding. Residency rules are complex and if you have not been resident in the UK or EU for the 3 years prior to the start of the studentship, please apply and we will check eligibility upon shortlisting.

Project Background

Resilience describes how fast a system recovers from perturbations. The Earth's carbon cycle has been perturbed repeatedly in the past, and is being perturbed again now by human activities. Crucial questions are: How resilient is the Earth system to perturbation? Has its resilience changed over time? And if so, why?

Excess carbon dioxide added to the atmosphere-ocean system is buffered by the dissolution of carbonate sediments on land and on the seafloor and ultimately removed by the weathering of silicate rocks and re-deposition of carbonate sediments. An overlooked factor in this Earth system response is the relative exposure and erosion of carbonate sediments on land and their potential to enhance CO2 drawdown. 

For example, large beds of Cretaceous carbonates (including chalk) have subsequently been uplifted and stand as readily weathered cliff face coastlines, outcrops and Karst/cave systems. This project will examine the contribution of enhanced carbonate weathering to accelerating recovery from past and present carbon cycle perturbations.

Project Aims and Methods 

This project aims to quantify the contribution of enhanced carbonate weathering to Earth system resilience. Prospective students are encouraged to help design the project. 

A proposed focus is: Did the uplift of large beds of Cretaceous chalk enhance Earth system resilience in response to the Paleocene-Eocene Thermal Maximum (PETM) 55 million years ago? And will it accelerate Earth system recovery from anthropogenic perturbation?

Potential methods include: The use of remote sensing and GIS to establish the present day global extent of chalk (and other carbonate) coastlines. Lab experiments to obtain rate information on erosion and/or chemical weathering rates. Field measurements to establish the alkalinity contribution of chalk cliff erosion. Refining of models of carbonate weathering with this information. Earth system modelling with cGENIE to quantify the global impact of the weathering of uplifted carbonate (including chalk) platforms.

The project has a strong supervisory foundation: Lenton helped developed the GENIE model and its weathering module (Colbourn et al. 2015), which has been used to study carbon cycle perturbations, including the PETM (Gutjhar et al. 2017), and anthropogenic perturbation. Schuster is an expert in ocean carbon and carbonate chemistry (Schuster et al., 2013; Le Quere et al. 2018). Halloran has 3D modelling and paleo-proxy expertise (Rickaby and Halloran, 2005) and has worked extensively on the formation and dissolution of carbonate sediments (Iglesias-Rodriguez et al., 2008).


Uplifted Cretaceous chalk forming the White Cliffs of Dover (by Immanuel Giel - Own work, CC BY-SA 3.0,



Schematic of the cGENIE Earth system model

Candidate Requirements

We seek a creative student with the ability to generate and test hypotheses using mixed methods. They should be a systems thinker with good mathematical and software skills, and relevant knowledge of Earth history, the carbon cycle, and carbonate chemistry. Computer modelling experience would be advantageous.


In addition to the training offered through the NERC GW4+ DTP, and specific scientific training offered by the supervisors, the student will be provided with the ‘My Career Zone’ online tool to manage their training, careers servicing, and find graduate positions.  My Career Zone provides access to over 60 PhD specific courses, and an 11 module online research skills course. An example 3 yr syllabus leads through efficient reading in research, what/when/how to share data; writing CVs and cover letters, networking and team-building, and public engagement; then the importance of impact, public engagement, intellectual property and commercialisation.  As part of the Global Systems Institute, the student will work alongside world-leading academics, PDRAs and PhD students, all investigating questions of Earth system change.

References / Background reading list 

Colbourn, G., A. Ridgwell and T. M. Lenton (2015). "The time scale of the silicate weathering negative feedback on atmospheric CO2." Global Biogeochemical Cycles 29(5): 583-596.

Gutjahr, M., A. Ridgwell, P. F. Sexton, E. Anagnostou, P. N. Pearson, H. Pälike, R. D. Norris, E. Thomas and G. L. Foster (2017). "Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum." Nature 548: 573.

Iglesias-Rodriguez*, M.D., P.R. Halloran* (*Co-lead Authors), et al. (2008). “Phytoplankton calcification in a high CO2 world.” Science 320: 336-340.

Le Quere, C., et al. (2018). “The Global carbon budget 2018.” Earth System Science Data 10: 2141-2194.

Rickaby, R.E.M. and P. Halloran (2005). “Cool La Niña during the warmth of the Pliocene?” Science 307: 1948-1952.

Schuster, U., et al. (2013) “An assessment of the Atlantic and Arctic sea–air CO2 fluxes, 1990–2009.” Biogeosciences 10: 607-627, doi:10.5194/bg-10-607-2013.

Entry requirements

Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK.   Applicants with a Lower Second Class degree will be considered if they also have Master’s degree.  Applicants with a minimum of Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.

All applicants would need to meet our English language requirements by the start of the  project

How to apply

In the application process you will be asked to upload several documents.  Please note our preferred format is PDF, each file named with your surname and the name of the document, eg. “Smith – CV.pdf”, “Smith – Cover Letter.pdf”, “Smith – Transcript.pdf”.

  • CV
  • Letter of application outlining your academic interests, prior research experience and reasons for wishing to undertake the project.
  • Transcript(s) giving full details of subjects studied and grades/marks obtained.  This should be an interim transcript if you are still studying.
  • If you are not a national of a majority English-speaking country you will need to submit evidence of your current proficiency in English.

Reference information
You will be asked to name 2 referees as part of the application process, however we will not expect receipt of references until after the shortlisting stage. Your referees should not be from the prospective supervisory team.

If you are shortlisted for interview, please ensure that your two academic referees email their references to the, 7 days prior to the interview dates.  Please note that we will not be contacting referees to request references, you must arrange for them to be submitted to us by the deadline.

References should be submitted by your referees to us directly in the form of a letter. Referees must email their references to us from their institutional email accounts. We cannot accept references from personal/private email accounts, unless it is a scanned document on institutional headed paper and signed by the referee.

All application documents must be submitted in English. Certified translated copies of academic qualifications must also be provided.

The closing date for applications is 1600 hours GMT Monday 6 January 2020.  Interviews will be held between 10 and 21 February 2020.  For more information about the NERC GW4+ DPT please visit

If you have any general enquiries about the application process please email  Project-specific queries should be directed to the lead supervisor.

Data Sharing
During the application process, the University may need to make certain disclosures of your personal data to third parties to be able to administer your application, carry out interviews and select candidates.  These are not limited to, but may include disclosures to:

  • the selection panel and/or management board or equivalent of the relevant programme, which is likely to include staff from one or more other HEIs;
  • administrative staff at one or more other HEIs participating in the relevant programme.

Such disclosures will always be kept to the minimum amount of personal data required for the specific purpose. Your sensitive personal data (relating to disability and race/ethnicity) will not be disclosed without your explicit consent.


Application deadline:6th January 2020
Value:£15,009 per annum for 2019-20
Duration of award:per year
Contact: PGR Enquiries