Bridging the gap between stakeholders and climate modellers

In October 2008, Dr Hans Visser and Professor Arthur Petersen reported in the scientific journal Climatic Change on the development and communication of a new indicator of climatic change for the Netherlands, the likelihood of holding large-scale outdoor ice-skating marathons (the ‘Elfstedentocht’ or Frisian Eleven City Ice Skating Marathon). Outdoor skating has a very strong public appeal in the Netherlands, and the diminishing chances of holding such events provide an indicator of climate change that most Dutch can easily relate to. The finding made headlines in the Netherlands and around the world

Bridging the gap

As a follow-up to this initial study, PBL – together with VU University Amsterdam and KNMI – launched a larger project called ‘Bridging the Gap between Stakeholders and Climate Modellers: Demand-driven adaptation assessment of uncertain changes in weather extremes’ (2010–2013), which was funded by the Netherlands Organisation for Scientific Research and the Knowledge for Climate Research Programme. The project is led by Professor Arthur Petersen, Chief Scientist of the PBL Netherlands Environmental Assessment Agency.

In the Bridging the Gap project, the collaborating institutes address two types of uncertainties; those that are inherent to climate modelling, and those with respect to the risks of specific harmful impacts of extreme weather events on (sectors of) society as stakeholders perceive them. The general aim of the project is threefold; it is divided into a methodological, an empirical and a policy aim to contribute to:

1. An integrated (social and natural science) methodology for demand-driven assessments of uncertainties, risks and options for climate adaptation governance;
2. Knowledge with respect to changes in weather extremes for the Netherlands, focusing on specific areas or sectors and including a thorough investigation of uncertainties; and
3. The identification and exploration of climate adaptation options, among other things, through a dialogue on weather extremes, and including climate scientists and stakeholders from various societal sectors.

The project consists of three stages (identifying stakeholder perspectives and scenarios; comparison and deliberation; and improvement of scenarios/exploring options for adaptation governance), the first two of which were completed in 2012. 

Stakeholder workshop

At the completion of the first stage, a workshop was organised to validate the outcomes of our social psychological study into perspectives on weather extremes and to learn about the interest in uncertainty information on climate predictions with respect to extremes. It turned out that the interest in an adequate communication of the uncertainty in short-term weather predictions (and warnings) was greater than in that relating to long-term climate-related predictions of changes in the weather.

Results

By applying social science methods, the project team has articulated six stakeholder perspectives related to weather extremes and their impacts on the Netherlands. These perspectives are: ‘Very disastrous, rescue needed’; ‘New versus old extremes’; ‘Prepare for (material) damage’; ‘Persons involved’; ‘Beyond imagination’; and ‘Natural resource management’. The study has been accepted for publication in Regional Environmental Change (first author: Dr Eleftheria Vasileiadou, VU).

Through the application of natural science methods, the uncertainty range for climate projections of temperature extremes in the Netherlands has been studied, using Regional Climate Models (RCMs) – from the EU FP6 project ENSEMBLES – and the ensemble of RCMs was found to significantly underestimate the observed trends, not only in the Netherlands, but over most of the north-western European land surface. Individual models would not do much better, with even the best performing models underestimating observed trends over large areas. It was concluded that these data should be used with caution when making adaptation decisions. This study has been accepted for publication in Environmental Research Letters (first author: Dr Erik Min, KNMI).

Bringing natural and social sciences together, it was found that traditional approaches to inform society on changes in the weather, involving extensive simulations and the provision of probabilistic information, do not work well. Recognising the inherent limits to the predictability of climate and the different epistemic values held by different groups of experts, an author team led by Professor Wilco Hazeleger (KNMI) argues for a different approach. Narratives describing existing knowledge of the physics of extreme weather events accompanied by simulations of extreme weather events in well-calibrated numerical weather prediction models in present-day climate and a potential future climate setting provide a realistic and physically consistent picture of the types of events that would require preparatory actions as well as the impacts of the adaptation decisions taken.