1. IWRM as a Tool for Adaptation to Climate Change Dealing with uncertainties

2. Goal and objectives of the session At the end of this session, participants will be familiar with the uncertainties involved in: Predicting impacts of climate change Adapting to the predicted impacts of climate change.

3. Uncertainties One thing is certain: Nothing is certain In this session:  Uncertainty and climate change  How to deal with uncertainties  Types of uncertainties  Adaptation to climate change under uncertainty: Prediction-oriented approaches Resilience-oriented approaches.

4. Climate change Changes in temperature and precipitation characterised by uncertainties regarding: magnitude timing spatial distribution As well as uncertainties with respect to vulnerabilities.

5. Feedbacks increasing uncertainties  Melting of ice/snow > reduced reflection sun’s radiation > increased heating  Thawing permafrost > release CO 2 and CH 4 > accelerating global warming  Higher land and ocean temperatures: reduced uptake of atmospheric CO 2.

6. Uncertainties in environmental management (Ravetz, 2005)  Increasingly dealing with situations where facts are uncertain, values in dispute, stakes high and decisions urgent  Weighing risks is a political task.

7. Uncertainties in water management  Uncertainty, variability and risk most important consequences of climate change  Climate change projections inconsistent and/or inaccurate at regional/local scales  Stationarity in weather and water systems not longer reliable basis for planning. Experience from the past is no longer a reliable guide for the future.

8. Challenges in water management  Improve predictions (temporal/spatial scales required by water managers)  Collaboration/communication between climate and water resources management community  Adaptive management: adaptive and flexible approaches to improve coping with uncertain developments vs finding optimum solutions >Institutional flexibility and a central role for stakeholders.

9. Typology of uncertainties: From ‘knowing for certain’ to ‘unknown’ Statistical: Range with probability, chances, probabilities Assuming underlying models are adequate, data representative Scenario: Ranges of possible outcomes: ‘What if?’ Recognized: Present, but can not be estimated (chaos, unknown processes) No scientific consensus, e.g. accelerated sea level rise, shut- down thermohaline ocean circulation.

10. Adaptation to CC under uncertainty Prediction-oriented:  Characterising, reducing, managing and communicating uncertainty  Increasing sophistication of modelling tools and techniques. Resilience-oriented:  Uncertainties can not be reduced  Learning from the past.

11. Prediction-oriented approaches IPCC approach:  Uncertain information by using CC scenarios as drivers for impacts from which adaptation strategies are developed. Risk approaches:  Identify, evaluate, select and implement actions to reduce risks (probability x consequences).

12. Frameworks for risk approaches (Dessai and van der Sluijs, 2007) 1.Identify key climatic variables 2.Create scenarios/ranges for these variables 3.Sensitivity analysis between CC and impacts 4.Identify impact thresholds 5.Carry out risk analysis 6.Evaluate risk and identify feedbacks 7.Consult stakeholders, analyse proposed adaptations, recommend planned adaptation options

13. Frameworks for risk approaches -2- (ten Brinke et al., 2008) Risk management cycle/safety chain Risk management Pro-action Eliminating structural causes of accidents and disasters to prevent them from happening in the first place (e.g. building restrictions in flood-prone areas) Prevention Taking measures beforehand that aim to prevent accidents and disasters, and limit the consequence in case such events do occur (e.g. building dykes) Crisis management Preparation Taking measures to ensure sufficient preparation to deal with accidents and disasters in case they happen (e.g. contingency planning) Response Actually dealing with accidents and disasters (e.g. response teams) Recovery All activities that lead to rapid recovery from the consequences of accidents and disasters, and ensuring that all those affected can return to the ‘normal’ situation and recover their equilibrium.

14. Frameworks for risk approaches -3- (PLANAT)

15. Frameworks for risk approaches -4- (Sullivan and Meigh, 2005)

16. Resilience-oriented approaches (Dessai and van der Sluijs, 2007)