CR2025_43 Predicting the surprises: Extreme events in Northern Europe

Lead Supervisor: Laura Wilcox, National Centre for Atmospheric Science and Department of Meteorology, University of Reading

Email: l.j.wilcox@reading.ac.uk

Co-supervisors: Bjørn Samset, CICERO Center for International Climate Research; Ed Hawkins, National Centre for Atmospheric Science and Department of Meteorology, University of Reading; Erich Fischer, ETH Zürich

Extreme weather events are increasingly causing physical and economic damages, and casualties. This includes heatwaves, extreme amounts of rainfall, storms, and more, all of which are now routinely assessed to have been made more serious by anthropogenic climate change.¹ However, many of these events still come as surprises, in spite of solid knowledge of how climate change is increasing climate risk.

A main reason why weather extremes keep surprising us is that they are rare, and often caused by uncommon meteorological conditions. Hence, we may not have experienced the conditions that cause a given extreme event since before global warming gained speed around 1970. A big challenge for climate science is therefore to go beyond just stating that these events will get more frequent and intense, to being able also to say which as yet unseen conditions are likely to cause strong impacts, and therefore surprise us.

In this project, you will work with new climate model output and state of the art methods to help predict these deadly surprises – far enough in advance that society has time to adapt. You will begin by analysing large ensembles of future climate simulations, and identifying events that are far beyond what we have experienced to date. You will then assess whether they occurred via physically plausible mechanisms, and if so, how these processes change as the world warms. You will study a selected set of very damaging scenarios in Northern Europe, drawn both from actual events and modelled possibilities, quantify how likely they are to occur, and consider how they might be made more or less damaging by interacting with the natural variations of the weather. You will also develop an overview of potential compound events, extreme events that happen together or in quick succession, making their total impact even more damaging.¹

This project has high scientific relevance as it goes beyond the standard exploration of extreme events in a warmer world by focusing on the combined natural and human induced causes of very extreme weather events in a given region. It is a highly timely project, since many of the datasets and techniques that will be used have not been available until recently. This includes large ensembles of future simulations,² techniques for increasing (or “boosting”) the number of simulated events even though they are very rare,³ and novel AI-based techniques for scanning and digesting large and highly diverse datasets. As extreme weather events continue to increase in strength and number, there is high interest from governments and businesses in information that can aid early adaptation and reduce the impacts of future disasters. Hence, this is a project with high societal relevance.

Technically, the project will entail analysis of the same climate model scenarios used by the Intergovernmental Panel on Climate Change (IPCC).⁴ You will use high performance computing to run additional climate simulations with the UK Earth System Model (UKESM), perform ensemble boosting, and use machine learning to analyse large datasets. However, you will also need creativity in order to identify potentially damaging cases, in a sense anticipating the surprises before they occur. All this will be done as part of an international team of experts, including the CASE partner institution CICERO in Oslo, Norway, and ETH Zürich, Switzerland. As the results can be expected to be of relevance to the public, it is an advantage to also have an interest in communicating them beyond academic circles.

By the end of the project, the candidate can expect to be among the leading experts on future extreme events in Northern Europe, their causes and potential impacts, and to be a key player in helping society predict some of the worst surprises that climate change still has in store.

Training opportunities: 

The student will have the opportunity to work for at least 3 months at CICERO. There, they will experience a highly interdisciplinary, non-academic research environment, and interact with researchers at the forefront of broader aspects of the climate problem to explore extensions of their work beyond analysis of the physical climate.

The student will be offered NCAS courses in atmospheric science, scientific computing, python, and the use of the UK Earth System Model, alongside the opportunity to attend the Climate Modelling Summer School. During the project the student will develop strong programming, data management, and presentation skills. 

Student profile: 

This project would suit a student with a background in physical or mathematical sciences, perhaps specialising in atmospheric physics or similar. The student must have strong analytical skills. During the project the student will be expected to develop the necessary computer programming and climate data analysis skills. Previous experience in programming or the use of large datasets would be beneficial. 

Co-Sponsorship details: 

This project will receive a CASE award from the CICERO Center for International Climate Research.

References

1. AghaKouchak, A., Chiang, F., Huning, L. S., Love, C. A., Mallakpour, I., Mazdiyasni, O., Moftakhari, H., Papalexiou, S. M., Ragno, E., and Sadegh, M. (2020): Climate Extremes and Compound Hazards in a Warming World, Annual Review of Earth and Planetary Sciences, 48, 519-548, doi:10.1146/annurev-earth-071719-055228

2. Iles, C. E., Samset, B. H., Sandstad, M., Schuhen, N., Wilcox, L. J., and Lund, M. T. (2024): Strong regional trends in extreme weather over the next two decades under high- and low-emissions pathways, Nature Geoscience, 17, 845-850, doi:10.1038/s41561-024-01511-4

1. Fischer, E. M., Beyerle, U., Bloin-Wibe, L. et al. (2023): Storylines for unprecedented heatwaves based on ensemble boosting. Nature Communications, 14, 4643, doi: 10.1038/s41467-023-40112-4
2. IPCC, 2021: Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group 1 to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caus, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 3-32, doi:10.1017/9781009157896.001
3. Rüther, D.C., Lindsay, E. & Slåtten, M.S. (2024): Landslide inventory: ‘Hans’ storm southern Norway, August 7–9, 2023, Landslides, 21, 1155–1159, doi:10.1007/s10346-024-02222-y
4. Ssu, CC BY-SA 4.0, via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Flommen_i_Ringerike_2023_-_H%C3%B8nefossen_stor.jpg