4-9 September 2022, Bonn, Germany
Physical Climate Storylines to inform decision making.


Physical climate storylines (PCS) are physically self-consistent unfoldings of past events, or of plausible future events. The PCS approach is intended to inform stakeholders about the possible impact chains of climate hazards by either complementing or replacing probabilistic approaches to representing uncertainty about future climate. PCS are developed with the aim of incorporating stakeholder perspectives either by addressing questions identified by stakeholders or by co-producing storylines with stakeholders themselves. In many cases, developing PCS involves combining the analysis of model output and observations at varying spatiotemporal scales – and, in particular, the output of climate and weather prediction models. For this session, we encourage submissions that develop one of the following: (i) physical climate storylines to address information needs of stakeholders for climate risk assessment and management, (ii) critical/evaluative perspectives on existing storyline methods, (iii) critical perspectives on the PCS approach that evaluate their merits and shortcomings as tools for stakeholder engagement and/or tools for delivering information targeted to their intended users.

Co-organized by UP3
Convener: Marina Baldissera Pacchetti | Co-conveners: Bart van den Hurk, Theodore Shepherd, Suraje Dessai, Karin van der Wiel, Jana Sillmann
| Mon, 05 Sep, 16:00–17:30 (CEST)|Room HS 1
| Attendance Tue, 06 Sep, 09:00–10:30 (CEST) | Display Tue, 06 Sep, 08:00–18:00|b-IT poster area

Session assets

Session materials Session summary

Orals: Mon, 05 Sep | Room HS 1

Chairpersons: Marina Baldissera Pacchetti, Rohit Ghosh
Onsite presentation
Christopher Goddard and Fai Fung

Climate storylines, or narratives, are gaining traction in climate science and services as a means of producing and communicating application relevant information. We have performed case studies of co-produced storylines to assess their usefulness and usability as a process of producing information, as well as communicating it in a final stakeholder product. This aims to add to the limited pool of examples of the real-world application of these concepts. 

We present an example of working with the heritage sector in the UK to co-produce storylines of summer temperature and winter rainfall hazards. This is a sector with a variety of assets and operations spread over countries, clearly exposed to weather and climate hazards, and organisations are beginning to perform risk assessments and adaptation planning. The stakeholder, and a wider focus group of sector representatives from around Europe, provided feedback and suggestions which add to the limited body of evidence assessing storylines as both a process and product directly with users. A particular focus was to expose the uncertainty in climate projection products and uncover the application relevance of this. We showcase how a weather forecasting product, DECIDER weather patterns, can be used on climate timescales to help understand hazards and the role of different types of uncertainty.  

A major finding was that the value of the co-production process was highlighted, which may be even more important than the storylines themselves for building credibility and confidence in the climate projection information. Framing projection information using past events and explaining uncertainty and regional variations using the weather patterns were found to be key aspects of the information for the stakeholder. Working through the process of tailoring the information to an application relevant range also proved to be an effective mechanism for enabling discussion about the risk appetite and uncertainty budget of the related planning and decisions.  

How to cite: Goddard, C. and Fung, F.: Co-produced storylines of climate hazard uncertainty for the heritage sector, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-372, https://doi.org/10.5194/ems2022-372, 2022.

Onsite presentation
Alina Mastai, Kathrin Wehrli, Sven Kotlarski, and Erich Fischer

Storylines provide a way to communicate climate change and especially changes in extreme events in a tangible way for the public and decision makers by putting the focus on associated risks and impacts. In this work, storylines are created for the 2003 summer heatwave in Switzerland. For this purpose, an analogous event is searched for in the already existing Climate Scenarios for Switzerland (CH2018). This event shall be as extreme in the future climate as 2003 was in its time. Building storylines for this future extreme event, we demonstrate how a 2003-like summer might be like by the end of the Century assuming no climate change mitigation. Specific indicators are chosen to develop four individual heat-related storylines and enabling a direct comparison between 2003 and the future hot summer. For the future summer, the number of hiking weather days in the Alps is projected to increase on the one hand, while on the other hand also fire danger increases massively. More and longer heatwaves may aggravate heat-related health issues and additional generations of agricultural pests could threaten agricultural yields.

With these storylines of a similar future heatwave, we gain a better understanding of locally relevant processes, get insight into how extreme events quantitatively change with the warming climate, give examples of possible impacts, and finally try to stimulate public awareness for possible consequences of future climate change. We explore different ways of visualizing and communicating the results, which may find broader application to inform Swiss stakeholders about future climate change and its possible impacts.

How to cite: Mastai, A., Wehrli, K., Kotlarski, S., and Fischer, E.: Storylines of future climate extremes in Switzerland, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-469, https://doi.org/10.5194/ems2022-469, 2022.

Onsite presentation
Ana Lopez and Gil Lizcano

Offering climate services to the wind energy industry is not without its challenges. Users are curious about the potential impacts of climate change on their projects. While estimates of wind resources are based on historical assessments, many questions arise. What if 20 years of past data is not enough to sample the internal variability of the site? Will the long term average wind speed change beyond the margins already taken into account in the project design? Will extreme speeds change in such a way that design parameters will no longer be valid? Very often, however, these users are reluctant to use information, specifically time series, that cannot be “correlated” with their onsite measurements.

In this presentation we describe our journey as a climate services SME, in search of tools and approaches that we could use not only to provide robust information to these users, but also information that they could trust and eventually incorporate in their decision making. 

In particular, we focus on a use case building storylines for a concrete wind development target area. These storylines are built as  plausible future conditions that are consistent with the current climate projections, and at the same time maximally sample their uncertainty. Our storylines provide a rationale not just to estimate the potential impacts of climate change on wind resources, but also to understand the mechanisms driving these changes and the robustness of the climate model projections. Additionally, being conditioned on for instance, different levels of global warming, they provide the wind resource scenarios that can be fed into climate risks analysis now being required by new sustainability regulations, such as the ‘EU taxonomy for sustainable activities’.  

Faced with the challenge of providing uncertain climate change information to users strongly tied to observation-driven reconstructions of climate conditions, we believe that these storylines offer an opportunity to facilitate the adoption of climate change information by a range of users, from the technical experts doing the energy assessment, to the management in charge of strategic decisions.

How to cite: Lopez, A. and Lizcano, G.: Building storylines for wind resources: our experience with users, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-494, https://doi.org/10.5194/ems2022-494, 2022.

Onsite presentation
Ertug Ercin, Alexander Kaune, and Cagri Karaman

Europe is the major chocolate manufacturer in the world. With a market value of 40 billion euros, the sector not only serves the continent’s internal chocolate demand but supplies most of the world, accounting for more than 76% of global chocolate sales. Yet the sector is highly dependent on imports of chocolate’s main ingredient, cocoa, from beyond Europe, mainly from West Africa. This dependency means that the sector is vulnerable to climate extremes, and possible climate change impacts, that occur in cocoa exporting regions. This study uses the climate storyline approach to build links between extreme climatic events occurring in two major West African cocoa exporting countries and their potential consequences on European society and its economy. It aims to provide cross-border climate risk information to the chocolate industry in Europe.

The climate storyline approach is inspired by a drought event in West Africa in 1983, which resulted in cocoa production losses of up to 60% in the region. Consequently, cocoa prices spiked and there was a shortage of supply which affected prices for both chocolate producers and consumers in Europe. The storyline approach includes a modeling chain of these events, i.e., the impacts of the drought on cacao yields and cocoa production in the exporting region; consequent changes to the trade volume between the region and Europe, and to cocoa prices; and the cascading economic impacts of these changes on the wider chocolate industry. Furthermore, drought impacts on cacao yields and cocoa production under future climatic conditions are determined for the periods 2021-2040, 2041-2060 and 2081-2100 under RCP 2.6, 7.0 and 8.5 scenarios. Next, the storyline modeling chain is applied to the future climatic conditions to reveal how climate change in West Africa could impact European society and its economy, with a particular focus on chocolate manufacturing.

How to cite: Ercin, E., Kaune, A., and Karaman, C.: A climate storyline approach to inform private sector decisions on cross-border climate risks:A case study of the chocolate industry in Europe, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-416, https://doi.org/10.5194/ems2022-416, 2022.

Onsite presentation
Aditya Narayan Mishra, Douglas Maraun, Raphael Knevels, Heimo Truhetz, Emanuele Bevacqua, Herwig Proske, Helene Petschko, Philip Leopold, Alexander Brenning, Giuseppe Zappa, and Armin Schaffer

In the June of 2009 central Europe witnessed a rampant rainfall spell that spread across populated areas of the country. High-intensity rainfall caused 3000+ landslides in the southeastern Austrian state of Styria, and property damages worth €10 Million. Elsewhere in Austria, flooding amounted to reparations worth €40 Million. Numerous synoptic-scale studies indicated the presence of a cut-off low over central Europe and excessive moisture convergence behind the extreme event. In a warmer climate change scenario, such an extreme precipitation event may manifest into a more intense event due to the higher water holding capacity of air with increased temperatures, but this reasoning may not be so straightforward considering the complex physics of precipitation, more so in a topographically heterogeneous region such as the GAR (Greater Alpine Region).

The flooding and landslides caused in the region raise an alarm and thus motivate this study whereby we investigate if the rainfall event did become stronger with time due to climate change compared to how it would have been in a counterfactual (climate change free) past. Here we have deployed the CCLM high-resolution regional model coupled with a statistical landslide model to simulate this event (rainfall and landslides) in a pseudo (surrogate) warming scenario. A marked decrease in rainfall intensity is observed in the simulations for a 1 K cooler climate (pre-industrial past) and the consequent landslide risk could reduce by up to 20%. In the future,  depending on the changes in rainfall and soil moisture, the area affected during a 2009-type event could grow by 45% at 4 K global warming, although a slight reduction is also possible.

In this novel event-based study, we discuss the results from the lens of attribution perspective - how conditional attribution is much more useful compared to the conventional risk-based approach of attributing extreme events. We develop physical storylines to address the increasing risks of landslides in the region.

How to cite: Mishra, A. N., Maraun, D., Knevels, R., Truhetz, H., Bevacqua, E., Proske, H., Petschko, H., Leopold, P., Brenning, A., Zappa, G., and Schaffer, A.: Storylines: A severe rainfall-landslide event in Past, Present & Future climate scenarios, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-313, https://doi.org/10.5194/ems2022-313, 2022.

Display time: Tue, 6 Sep 08:00–Tue, 6 Sep 18:00

Posters: Tue, 6 Sep, 09:00–10:30 | b-IT poster area

Chairperson: Marina Baldissera Pacchetti
Onsite presentation
Marina Baldissera Pacchetti, Liese Coulter, Suraje Dessai, Theodore Shepherd, Jana Sillmann, and Bart Van Den Hurk

The Physical Climate Storyline (PCS) approach is increasingly recognized by the research community as a tool to produce and communicate decision-relevant climate risk information. While PCS is generally understood as a single concept, different methodologies are applied according to the aims and purposes of the approach. To unpack this diversity of detail, this paper gives an overview of the key methodological practices and assumptions, i.e. the “logics” that are associated with variants of the PCS approach. We analyze physical climate storylines as both a product and a process and recognize that (i) those who build the storylines (e.g. physical climate scientists, interdisciplinary groups of scientists, or transdisciplinary groups of scientists and societal stakeholders) and (ii) the purpose for which these storylines are built (e.g. improving scientific understanding or communicating information) influence key features of the methodology (process) and hence key features of the storyline (product). We note that PCS can have cognitive aims, i.e. aims related to the pursuit of knowledge and hence promote cognitive values, and non-cognitive aims, i.e. the practical, social and ethical aims of the knowledge that is produced, and hence promote non-cognitive values. We then examine how value judgements are implicitly or explicitly included in the aims and construction of PCS. We conclude the discussion by suggesting that the PCS approach can further mature (i) in the way it incorporates the narrative element, in particular in trans- and multi-disciplinary contexts, (ii) in the way it incorporates value judgments, and (iii) in the way that the evidence chosen to build PCS constrains what is considered plausible.

How to cite: Baldissera Pacchetti, M., Coulter, L., Dessai, S., Shepherd, T., Sillmann, J., and Van Den Hurk, B.: Unpacking the logics of physical climate storylines, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-586, https://doi.org/10.5194/ems2022-586, 2022.

Onsite presentation
Fai Fung, Christopher Goddard, Carol McSweeney, Tom Crocker, Dominic Matte, Andrew Ballinger, Gabi Hegerl, Christopher O'Reilly, Antje Weisheimer, Karin Van der Wiel, and Renate Wilcke

The European Climate Prediction system (EUCP) project aimed to lay the foundation for a future regional climate prediction system for Europe. An important element of this is the role of narrative or storylines approaches in data production and scientific investigation, as well as a user product. We will present the results of our investigations which sought to understand the potential advantages and challenges in developing physically based climate storylines as part of a climate service by addressing the questions

  • What are climate storylines and where are they useful?
  • How could storylines bring together various outputs of EUCP state-of-the-art climate science attempting to reduce uncertainty and complexity in climate projections, and seamlessly combine them with decadal predictions?
  • What are the challenges of producing them as a service?

The body of EUCP work included two case studies of co-producing storylines as a user product, revealing the potential usefulness for applications. These included the heritage and water supply management sectors which are at different stages of adaptation management. We also reflect on the potential of event-based future storylines: one using a convection-permitting model to provide attribution statements for the Copenhagen flooding event in July 2011 and another using large ensembles to construct storylines of the European summer 2018 drought under different pseudo-global warming. Novel scientific studies were also performed which could form the scientific building blocks of climate storylines including an algorithmic clustering approach and approaches to producing more realistic climate variability. Finally, we will present a tool for performing multiple lines of evidence assessments that could aid storylines development.

How to cite: Fung, F., Goddard, C., McSweeney, C., Crocker, T., Matte, D., Ballinger, A., Hegerl, G., O'Reilly, C., Weisheimer, A., Van der Wiel, K., and Wilcke, R.: Building storylines for applications: what have we learned in the EUCP project?, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-444, https://doi.org/10.5194/ems2022-444, 2022.

Onsite presentation
Rohit Ghosh and Ted Shepherd

The dry half of the year from May to October over the Maritime continent is a crucial period. Because a severely dry year could lead to unprecedented damages due to forest fires. The amount of rainfall during this period is closely tied to the sea surface temperature (SST) evolution over the tropical Pacific Ocean. The future change in the tropical Pacific SST has uncertainty with majority of the climate models showing a higher warming over eastern tropical Pacific. However multiple climate models show a higher warming rate over the western tropical Pacific, known as the warm pool region. This feature can also be seen in observations over the last 120 years. The effect of this differing tropical Pacific SST evolution can have contrasting influence over the maritime continent precipitation. Therefore, this study provides a risk-based estimate of the future dry season maritime continent precipitation, which is based on the possible evolution of tropical Pacific SST through physical climate storyline approach. We provide storylines of future dry period precipitation using the outputs of 38 climate models from Coupled Model Intercomparison Project version 6 (CMIP6). Our results suggest that a higher basin wide tropical Pacific warming with higher warming in the eastern tropical Pacific than the west would lead to a drier condition over the Islands of Sumatra and Java. Whereas lower increase in basin wide tropical Pacific SST with a warmer western tropical Pacific, which we saw in observations, would lead to wetter condition over the Islands of Borneo and Neu Guinea.


How to cite: Ghosh, R. and Shepherd, T.: Storylines of Maritime Continent dry season precipitation changes under global warming, EMS Annual Meeting 2022, Bonn, Germany, 5–9 Sep 2022, EMS2022-558, https://doi.org/10.5194/ems2022-558, 2022.

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