PhD Studentship - Engineering the Ocean-atmosphere Interface: Accelerating Atmospheric CO2 Removal into Seawater

Engineering the ocean-atmosphere interface: accelerating atmospheric CO2 removal into seawater – PhD Ref: 6084

About the award

Supervisors

Professor Paul Halloran, University of Exeter, Department of Physical Geography

Professor Rod Wilson, University of Exeter, Department of Biosciences

Professor Nicholas Harmer, University of Exeter, Department of Biosciences

How do you engineer seawater to pull carbon dioxide out of the atmosphere and help to mitigate climate change?

Removing carbon dioxide from the atmosphere at enormous scale is likely to be an important part of tackling climate change. The ocean naturally exchanges CO2 with the air, but because the alkalinity of that seawater buffers CO2, the amount of carbon dissolved in the ocean is vastly greater than in the atmosphere. For context, if you took all the CO2 that humanity has every emitted and stirred it into the ocean, the seawater carbon concentration would only increase by about 2%.

An extremely promising technique, known as Ocean Alkalinity Enhancement, aims to increase the buffering of CO2 by seawater. This would allow seawater to take up even more atmospheric CO2, helping us to balance the emissions from activities - such as flying and farming - that we don’t know how to decarbonise, and potentially even begin to reverse climate change.

But there is a fundamental problem.

If we increase the capacity of seawater to store carbon, atmospheric CO₂ does not instantaneously move into the water. The rate at which CO₂ crosses the air-water interface is the major bottleneck, with implications around marine ecosystem impacts, scalability, verification and cost. Overcoming that bottleneck could transform the way marine carbon dioxide removal is designed and deployed. This PhD, part of the CASE4CDR project - aligned with ARIA’s Resilient Climate and Ecosystems Opportunity Space - will investigate how to make that happen.

You will work at the interface of environmental engineering, marine chemistry, enzymology, fluid mechanics, and climate science to understand, quantify and ultimately engineer the transfer of CO2 from air into seawater.

A major focus will be the development and optimisation of systems designed to maximise gas exchange while minimising the energy, material and environmental costs of carbon removal.

You will design experiments to quantify CO2 exchange between air and seawater and investigate how performance changes with a wide range of factors. You will establish rigorous carbon budgets to quantify carbon removal. Working closely with a second PhD researcher and the project supervisors, you will explore a potentially transformative way of accelerating this process.

From laboratory experiments to the sea

A particularly exciting feature of this PhD is that, with the right safeguards in place, the work is intended to move beyond laboratory proof-of-concept.

Upon meeting key acceptance criteria, you will help translate fundamental measurements and engineering designs into trials using real seawater at the SeaCURE pilot facility situated on the coast in Weymouth.

This will create a unique opportunity to follow an emerging climate technology through multiple stages of development: from calculations and controlled laboratory experiments, through engineering and instrumentation, to operation in a real marine environment.

Carbon dioxide removal cannot succeed on engineering performance alone.

You will join a wider interdisciplinary project examining what would actually be required to deploy a new marine carbon removal technology responsibly. Alongside your core research, you will have opportunities to contribute to work around environmental permitting, regulation, environmental impacts, public and stakeholder engagement, and trials at the Weymouth plant.

That wider perspective is important. The central question is not just can we build it, but can we develop a carbon-removal system that is measurable, environmentally responsible, socially acceptable and capable of eventually operating at meaningful scale.

What are we looking for?

The project would particularly suit someone who enjoys working at pace, building things and solving quantitative problems, but also zooming out from the lab scale to understand the real word social, political and practical deployment opportunities and constraints around Carbon Dioxide Removal. You might come from engineering, chemistry, physics, biosciences, environmental science, oceanography or another quantitative discipline.

What matters most is enthusiasm for rigorous experimental science and problem solving, and being powerfully motivated by working on one of the defining problems of our time.

The University of Exeter is inviting applications for a PhD studentship aligned with ARIA’s Resilient Climate and Ecosystems Opportunity Space, to commence on 4 January 2027 or as soon as possible thereafter. For eligible candidates the studentship will cover Home tuition fees plus an annual tax-free stipend of at least £21,805 for 3.5 years full-time, or pro rata for part-time study. The student would be based in the Institute for Climate and Nature in the Environment, Science and Economy at the Streatham Campus in Exeter.

International students who wish to apply for this opportunity will need to be in the UK ahead of the programme start date on 4 January 2027, so will need to ensure they have any student visas (if applicable) and ATAS clearance in place ahead of this date. Students who pay international tuition fees are eligible to apply, but the award will only cover part of the international fees (approximately £27,000). The international fee in 2026/27 is £28,700 and will increase in 27/28.

International applicants will need to cover additional costs, including:

• Student visa fees
• Immigration Health Surcharge
• Relocation expenses associated with moving to the UK to undertake the PhD.

International fee-paying applicants should ensure they have sufficient funds to meet these costs before applying.

The conditions for eligibility of home fees status are complex and you will need to seek advice if you have moved to or from the UK (or Republic of Ireland) within the past 3 years or have applied for settled status under the EU Settlement Scheme.

The collaboration involves a project partner who is providing funding and other material support to the project, this means there may be special terms that apply to the project, these will be discussed with candidates at interview and fully set out in the offer letter. The collaboration with the named project partner is subject to contract. Please note full details of the project partner’s contribution and involvement with the project is still to be confirmed and may change during the course of contract negotiations. Full details will be confirmed at offer stage.

For general information about this studentship and the application process, please contact PGRApplicants@exeter.ac.uk. Project specific queries should be directed to Paul Halloran (p.halloran@exeter.ac.uk).

Entry requirements

Applicants for this studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of quantitative sciences such as chemistry, physics, biosciences, environmental science, oceanography.

If English is not your first language you will need to meet the English language requirements and provide proof of proficiency. Click here for more information.

How to apply

To apply, please click the ‘Apply Now’ button above. In the application process you will be asked to upload several documents:

• 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)
• Two references from referees familiar with your academic work. If your referees prefer, they can email the reference direct to PGRApplicants@exeter.ac.uk quoting the studentship reference number.
• If you are not a national of a majority English-speaking country you will need to submit evidence of your proficiency in English.

The closing date for applications is midnight on 26th November 2026. Interviews will be held virtually or on the University of Exeter Streatham Campus in the week commencing 30th November 2026.

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

Please quote reference 6084 on your application and in any correspondence about this studentship.

Summary