Copernicus Institute Universiteit Utrecht Taking uncertainty on board in decision making The example of adaptation to climate change

Copernicus Institute

Universiteit Utrecht

Taking uncertainty on board in decision making

The example of adaptation to climate change



Risk = Probability x Consequence

Lay attitudes involve more than just ‘risk’

• Severity and Nature of Consequences• Cultural Orientations (there is no single ‘public’)• Social Amplification Effects• Trust in Risk Managers / Science

Attitudes to risk and uncertainty



Nederland Later

Major anticipated problem areas•Sea level•River runoff•Groundwater pressure

hotspothotspothotspothotspot

Adaptation under what uncertainty?• Planned adaptation

– to single scenario of anticipated climate impacts (KNMI 2000 scenario)no uncertainty

– to single scenario of anticipated climate impacts + to variabilitystatistical uncertainty (without epistemic unc.)

– to range of scenario’s of anticipated climate impacts (KNMI 2006 scenario’s)scenario uncertainty

– to range of scenario’s of anticipated climate impacts + imaginable climate surprises (MNP Nederland Later)scenario uncertainty + recognized ignorance



Decision-making frameworks• Top down approaches

– Prevention Principle– IPCC approach– Risk approaches

• Bottom up approaches– Precautionary Principle– Engineering safety margin– Anticipating design– Resilience– Adaptive management– Human development approaches

• Mixed approaches– Adaptation Policy Framework– Robust decision making



IPCC seven step approach:1) Define problem (study area, sectors, etc.);2) Select method of assessment most appropriate to the

problems;3) Test methods/conduct sensitivity analysis;4) Select and apply climate change scenarios;5) Assess biophysical and socio-economic impacts;6) Assess autonomous adjustments;7) Evaluate adaptation strategies.

(Carter et al. 1994, Parry and Carter 1998)



Risk approach (UK-CIP)Eight stages decision framework:1. Identify problem and objectives2. Establish decision-making criteria3. Assess risk4. Identify options5. Appraise options6. Make decision7. Implement decision8. Monitor, evaluate and review.

Flexible characteristics:- cricular- Feedback and iteration- Stages 3, 4 and 5 are tiered. (identify, screen, prioritise and

evaluate before more detailed risk assessments and options appraisals are required.)

“The risk assessment endpoints should help the decision-maker define levels of risk (probabilities and consequences or impacts) that are acceptable, tolerable or unacceptable”



No regrets

• Favour adaptation strategies which will yield benefits (for other, less uncertain, policy concerns) regardless of whether or not climate impacts will occur.



Precautionary Principle“When human activities may lead to morally unacceptable harm

that is scientifically plausible but uncertain, actions shall be taken to avoid or diminish that harm.

Morally unacceptable harm refers to harm to humans or the environment that is• threatening to human life or health, or• serious and effectively irreversible, or• inequitable to present or future generations, or• imposed without adequate consideration of the human rights of those affected.The judgment of plausibility should be grounded in scientific analysis. Analysis should

be ongoing so that chosen actions are subject to review.Uncertainty may apply to, but need not be limited to, causality or the bounds of the

possible harm.Actions are interventions that are undertaken before harm occurs that seek to avoid or

diminish the harm. Actions should be chosen that are proportional to the seriousness of the potential harm, with consideration of their positive and negative consequences, and with an assessment of the moral implications of both action and inaction. The choice of action should be the result of a participatory process. ”

(UNESCO COMEST 2005)



Engineering Safety Factor / Conservative Design



Long term surprise scenario margin(e.g. Greenland, WAIS)

Engineering safety margin

Stronger foundation thanneeded under most plausiblescenarios

Flexibility to build higher dike later

“Anticipating design”



Adaptive management• Iterative feedback and learning based approach• Management as experiment• Emphasis in process and continuous learning

(trial and error, small step->evaluate->adjust)• Flexibility, flexibility, flexibility!

• Especially useful in small scale systems• May fail in case of surprises and discontinuities

in system response (if past experience from which you learned is not a key to the future)



Resilience

• If uncertainties about climate change are large, one can still know how the resilience of social-ecological systems can be enhanced

• Resilience is the capacity of a system to tolerate disturbance without collapsing into a qualitatively different, usually undesired, state

www.resalliance.org

Principles:

•Homeostasis

•Omnivory

•High flux

•Flatness

•Buffering

•Redundancy



Robust decision-making• Models are used as exploratory tools

instead of prediction• Uncertainty ranges to be explored can

be informed by the current state of scientific knowledge

• Adaptation decisions are assessed against climate change uncertainties until a robust strategy (least sensitive to uncertainties) is identified



Problem: Dimensioning of water supply system

Additional water required (Ml/d) to maintain levels of service in 2030 under different demand scenarios as a function of regional climate response uncertainty

Robustness exploration (Dessai, 2005)

25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50

-50

-25

0

25

50

Summer precipitation change (%)

Climate impacts uncertainty (%)

AWS

-75--50 -50--25 -25-0 0-25 25-50 50-75 75-100



decision making under uncertainty frameworks

Statistical uncertainty

Scenario uncertainty

Recognized ignorance

& surprises

IPCC approach + ++ --

Risk approaches ++ + --

Engineering safety margin ++ -

Anticipating design ++ + +

Resilience + ++

Adaptive management ++ - --

Prevention Principle ++ --

Precautionary Principle + ++ ++

Human development approaches + +

Adaptation Policy Framework + + +

Robust decision making + ++ +

Synthesis



Uncertainty assessment methods Statistical uncertainty

Scenario uncertainty

Recognized ignorance &

surprises

Scenario analysis ("surprise-free") ++ -

Expert elicitation + + +

Sensitivity analysis +

Monte Carlo ++ - -

Probabilistic multi model ensemble ++ +

Bayesian methods ++ -

NUSAP / Pedigree analysis + + ++

Fuzzy sets / imprecise probabilities + +

Stakeholder involvement + +

Quality Assurance / Quality Checklists + + ++

Extended peer review (review by stakeholders) + ++

Wild cards / surprise scenarios - + ++

Synthesis



Synthesis

Documents

Copernicus Institute Universiteit Utrecht Taking uncertainty on board in decision making The example of adaptation to climate change