1. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Break-out session Uncertainty, assumptions and value commitments Jeroen van der Sluijs (Chair) Naomi Oreskes (key-note) Barbara Regeer (young researcher) Anne Myhr (rapporteur)

2. Copernicus Institute Interfaces between Science & Society, Milano, 27-28 November 2003 Towards multi-dimensional uncertainty assessment for complex environmental problems Jeroen van der Sluijs (UU Copernicus Institute) j.p.vandersluijs@chem.uu.nl

3. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Insights on uncertainty Uncertainty is partly socially constructed and its assessment always involves subjective judgement Omitting uncertainty management can lead to scandals and crisis; undermines trust in the science More research does not necessarily reduce uncertainty –may reveal unforeseen complexities –irreducible uncertainty (intrinsic or practically) High quality  low uncertainty Shift in focus needed from reducing uncertainty towards a systematic management of uncertainty and value loadings Uncertainty is a multi-dimensional concept and can manifest itself at different locations

4. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Locations of uncertainty Sociopolitical and institutional context System boundary & problem framing Model –Model structure –Assumptions –Parameters Inputs –Scenarios –Data

5. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Dimensions of uncertainty Technical (inexactness) Methodological (unreliability) Epistemological (ignorance) Societal (limited social robustness)

6. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net NUSAP: Qualified Quantities Example pedigree matrix:

7. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Sensitivity Pedigree weakstrong low high NUSAP Diagnostic Diagram Danger zone Safe zone

8. Copernicus Institute Interfaces between Science & Society, Milano, 27-28 November 2003 Method for analysis of assumptions Applied to EO5 Environmental Indicators (Penny Kloprogge)

9. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net

10. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Calculation chain ozone deaths & hospital admittances 1Societal/demographical developments 2VOC and NOx emissions in the Netherlands and abroad 3Ozone concentrations 4Potential exposure to ozone 5Number of deaths/hospital admittances due to exposure  What are key-assumptions in this calculation and what is their pedigree?

11. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Value loading can be in: practical / disciplinary / epistemic / socio-political sense Pedigree criteria for reviewing assumptions: Plausibility Inter-subjectivity peers Inter-subjectivity stakeholders Choice space Influence of situational restrictions (time, money) Sensitivity to view and preferences of analyst Estimated influence on results

12. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Workshop reviewing assumptions Completion of list of key assumptions Rank assumptions according to importance Elicit pedigree scores Evaluate method

13. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Key assumptions ozone deaths and hospital admittances Uncertainty mainly determined by uncertainty in Relative Risk (RR) No differences in emissions abroad between the two scenarios Ozone concentration homogeneously distributed in 50 x 50 km grid cells Worst case meteo now = worst case future RR constant over time (while air pollution mixture may change!) Linear dose-effect relationship

14. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Example “traffic light” graph Assumption that there is a linear dose-effect relationship

15. Copernicus Institute Interfaces between Science & Society, Milano, 27-11-2003 more info: www.nusap.net Conclusions NUSAP system Can address all locations and dimensions of uncertainty Provides framework for synthesising qualitative and quantitative assessments of uncertainty Structures in depth review of strengths and weaknesses of knowledge bases and of assumptions Helps to focus research efforts on most problematic model components Can be used interactively in extended peer processes to structure the critical appraisal of knowledge bases for (sustainability) policies.