1. ASP Summer Colloquium on Uncertainty in Climate Change Research: An Integrated Approach Welcome! NCAR, Boulder, CO July 21 - August 6, 2014

2. Introduction to the ASP Summer Colloquium on Uncertainty in Climate Change Research: An Integrated Approach Linda O. Mearns National Center for Atmospheric Research NCAR, Boulder, CO July 21 - August 6, 2014

3. “To know one’s ignorance is the best part of knowledge” –Lao Tzu

4. “Any clear way, though it lead to death, is preferable to the tangle of uncertainty”. - Charles Horton Cooley, U.S. sociologist

5. “ Doubt is not a pleasant condition, but certainty is an absurd one.” -Voltaire

6. Uncertainty – what is it? A state of lack of knowledge or incomplete knowledge or more completely : A state of incomplete knowledge (about the future), often with a random component reflecting random processes (e.g, rolling of dice). Total uncertainty is a combination of random (aleatory) uncertainty and epistemic uncertainty (the incomplete knowledge due to complexity of world). Probability is viewed as the standard measure of uncertainty.

7. But first, what do we know?

8. Data from Climate Monitoring and Diagnostics Lab., NOAA. Data prior to 1974 from C. Keeling, Scripps Inst. Oceanogr. Changing Atmospheric Composition of CO 2 Mauna Loa, Hawaii Rate increasing ppm 390 380 370 360 350 340 330 320 310 1960 1970 1980 1990. 2000 2010 K. Trenberth

9. Entered graduate school Received PhD Got CO 2 sample

10. Mauna Loa Observatory

12. Sealing the Sample

13. Extremes Hurricane Sandy Made landfall on New Jersey shore October 29, 2012.

14. Example of Damage: what’s it got to do with climate change? Consolidated Edison electricity substation in lower Manahttan stopped working at 9 p.m. Monday evening Flood protection barrier was overtopped (designed to be 1.5 ft above 10 ft storm surge of record) Sandy’s storm surge = 14 ft

15. R. Henson

16. IPCC, 2001 The Integration Problem

17. Cascade of Uncertainty for Climate Change Research

18. Decision-Making (Assessment of needs, decision entry points, institutional constraints, politics etc.) Mitigation Adaptation Toward Decision-making as a Central Focus

19. Scientific Information in Decision Processes Physical Science Society Societal Issues Physical Science Other Knowledge Societal Issues Other Knowledge S. Moser

20. Developing Mitigation and Adaptation Strategies Moving from ‘Is Climate Change Happening?’ to ‘What do we do about it?’ Emphasis on Actionable Science

21. Positive Signs of Integration

22. IPCC WG2 (2014)

23. Risk Management ‘Iterative risk management is a useful framework for decision making in complex situations characterized by large potential consequences, persistent uncertainties, long time frames and multiple climatic and non-climatic influences changing over time.’ »IPCC, 2014 (WG2 SPM)

24. Why are we doing this Colloquium? To understand the strands of uncertainty throughout the climate change problem in order to maximize effectiveness in any one area. It does not mean that all participants are expected to always engage in highly interdisciplinary research. It does mean that hopefully your research activities will be informed by and benefit from the larger uncertainty context.

25. The Importance of Generational Change Stephen H. Schneider 1945 - 2010

26. The End

28. S. Schneider, 1978 in Climatic Limits to Growth ‘Tough decisions that have to be made generally are value judgments of how to weigh risks and benefits in the face of large uncertainties.’