Freezing Points: Ice Nucleation Experiments, Climate Intervention, and the Politics of the Sky
Background
Cirrus clouds have a significant impact on Earth’s climate, yet their formation—particularly the role of ice-nucleating particles (INPs)—remains poorly understood. The climate intervention strategy known as cirrus cloud thinning (CCT) aims to reduce warming by modifying these clouds, but it relies on uncertain science and raises complex political issues. This research area integrates laboratory studies of deposition-mode ice nucleation with critical analysis of how scientific knowledge is produced, interpreted, and used in policy and geopolitical contexts. By situating the researcher’s own scientific practice within these dynamics, the work will generate insights to inform decision-making around geoengineering proposals.
PhD Opportunity
This interdisciplinary PhD will explore both the physical science and socio-political dimensions of cirrus cloud interventions, while critically reflecting on the researcher’s role in shaping knowledge that may influence future decisions. On the scientific side, the student will conduct laboratory experiments on deposition-mode ice nucleation using a newly developed chamber, analysing samples collected via balloon-borne instruments from the upper troposphere. These experiments will advance understanding of cirrus formation and help assess the feasibility and potential impacts of interventions such as CCT.
In parallel, the student will examine how their findings—particularly uncertainties—are interpreted and mobilized in climate politics. This includes analysing how CCT fits within existing legal and institutional frameworks, identifying potential actors in its deployment, and tracing how scientific results are condensed and translated into policy discourse. The project will explicitly consider how the researcher’s own practices and interpretations contribute to these processes, offering a reflexive perspective on the co-production of science and politics.
The project is co-supervised by Dr. Thomas Whale (School of Earth and Environment), an expert in ice nucleation and atmospheric measurement, and Prof. Olaf Corry (POLIS), a leading scholar on the geopolitics of climate engineering. The student will engage with both scientific and policy communities, contributing to a more integrated understanding of climate risk and intervention. This unique combination of experimental science, social analysis, and reflexive practice will prepare the student to contribute meaningfully to future decision-making on climate interventions.
Applicant Profile
We welcome applicants from a wide range of disciplines across the physical and social sciences, as well as engineering. The ideal candidate will be curious about the intersection of climate science, politics, and ethics, and motivated to work across disciplinary boundaries.
Strong quantitative and practical skills are essential, as the project involves laboratory experimentation and data analysis. While prior experience in every area is not required—training will be provided—applicants should demonstrate confidence in handling data and problem-solving.
Equally important is a willingness to engage with political and institutional analysis, as the project examines how scientific knowledge co-produces societal (dis)orders. Strong communication skills, critical thinking, and openness to reflective and collaborative work will be highly valued.
Other information
Solar geoengineering research faces geopolitical deadlock (Science, 2025) https://www.science.org/doi/abs/10.1126/science.adr9237
Key Gaps in Models’ Physical Representation of Climate Intervention and Its Impacts (Journal of Advances in Modeling Earth Systems, 2025) https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024MS004872
