1. Atmospheric Research Coping with Climate Risk climate sensitivity, coping ranges and risk Roger N. Jones AIACC Training Workshop on Adaptation and Vulnerability TWAS, Trieste June 3-14 2002

2. Atmospheric Research Coverage Impacts are sensitive to climate variability and extremes Coping ranges as a tool to understand the relationship between V, I and A. Operationalising coping ranges for risk assessment

3. Atmospheric Research Impacts are sensitive to climate variability and extremes Sensitivity to climate is: how much a system or activity is affected by climate-related stimuli

4. Atmospheric Research Insensitive Unaffected by rain, hail, sun, wind or snow

5. Atmospheric Research Sensitive Easily affected by rain, hail, sun, wind and snow

6. Atmospheric Research Sensitivity to what?

7. Atmospheric Research Extreme temperature

8. Atmospheric Research Extreme temperature Increasing stress

9. Atmospheric Research How do we assess extremes? In two ways, rarity and impact: 1. As a rare event 2. As an event with extreme outcomes Extreme events are rare events with significant impacts, but under climate change may become more common

10. Atmospheric Research Types of extreme climate events

11. Atmospheric Research Confidence levels Climate Variable Atmospheric CO 2 concentration Global-mean sea-level Global-mean temperature Regional seasonal temperature Regional temperature extremes Regional seasonal precipitation/cloud cover Changes in climatic variability (e.g. El Niño, daily precipitation regimes) Rapid or non-linear change (e.g. disintegration of the West Antarctic Ice Sheet) High confidence Low confidence Very low or unknown

12. Atmospheric Research Modelling climate variability Most impacts are sensitive to climate variability rather than the mean (atmospheric CO 2 is a notable exception) Climate models represent climate variability relatively poorly Realistic and plausible scenarios of climate variability are needed

13. Atmospheric Research Linking climate to impacts Climate system Impacted activity Socio- economic system Current climate Current adaptations Future climate Future adaptations

14. Atmospheric Research IPCC 1994

15. Atmospheric Research Two approaches to V&A  V =  I –  A V =  I – A, t t = 0, current climate, reference or baseline Time t relates to the planning horizon

16. Atmospheric Research Coping with climate (variability and extremes) A system can cope with some combinations of climate but other combinations will cause damage The ability to cope is a function of the sensitivity of a system to climate and its response to that sensitivity This response is the interaction of socio- economic and biophysical factors

17. Atmospheric Research Coping range under current climate

18. Atmospheric Research Coping range under current climate - limited ability to cope

19. Atmospheric Research Coping range structure (1) A coping range exists where climate – socioeconomic interactions are beneficial or suffer only tolerable damage. The width of the coping range is in part due to historical adaptation It is separated from an area of vulnerability by a threshold. The threshold can be critical, marking a level of harm that is intolerable, or mark a given level of hazard Beyond the coping range and threshold is a zone of vulnerability

20. Atmospheric Research Coping range structure (2) Simple Expressed in terms of one or two climate variables (e.g. rainfall, temperature) Complex Expressed in terms of secondary or tertiary variables with a known relationship with climate (e.g. stream flow, crop yield, rates of infectious disease)

21. Atmospheric Research Coping range dynamics Two aspects of the coping range can change: 1. Climate 2. Socioeconomic (affecting the width of the coping range) a. autonomous socioeconomic change may increase or decrease the width b. climatic events may trigger a contraction (through damage) or an expansion (adaptation to similar future events) We would like to add c. expansion to reduce anticipated future vulnerability

22. Atmospheric Research Changing coping range - socioeconomic change

23. Atmospheric Research Changing coping range - response to climate stress

24. Atmospheric Research Future climate - no adaptation

25. Atmospheric Research Future climate with adaptation Policy Horizon

26. Atmospheric Research Thresholds A non-linear change in a measure or system, signalling a physical or behavioural change Climate-related thresholds are used to mark a level of hazard

27. Atmospheric Research Thresholds as climate hazards There are two ways to construct climate hazards to use as thresholds 1. Natural hazards approach – a fixed threshold such as 1 in 100-year flood, storm surge or given storm strength applied over time and space. Especially good for locating most vulnerable areas. 2. Vulnerability-based approach – the climatic conditions resulting in a degree of harm that exceed the limits of tolerance. Usually specific to a given activity and location (e.g. drought, water supply, crop yields). Useful when constructed with stakeholder participation.

28. Atmospheric Research Thresholds Biophysical (simple to complex) Tropical cyclone Coral bleaching ENSO event Island formation Island removal Socioeconomic (usually complex) Legal/regulatory Profit/loss Cultural Agricultural Critical

29. Atmospheric Research Critical thresholds A level considered to represent an unacceptable degree of harm This is a value judgement and may be decided by stakeholders, be a legal requirement, a safety requirement, a management threshold etc

30. Atmospheric Research Planning horizons

31. Atmospheric Research Using coping ranges to assess risk – current risk Choose a reference or baseline period pertinent to both climate and the socioeconomic background Calculate threshold exceedance based on climate exposure during the reference period Existing adaptations and those needed to reduce risk under present climate provide the short-term options for a ‘win-win’ adaptation strategy (helping cost-benefit and efficiency criteria)

32. Atmospheric Research Using coping ranges to assess risk – future risk Each scenario will give a different probability of threshold exceedance If using single, or several scenarios, these should be related to the full range of uncertainty for climate change, when communicating results The effect of climate and socioeconomic scenarios can be assessed separately or together Methods can range from semi-quantitative (simple) through to the application of advanced probabilistic techniques (difficult but interesting)

33. Atmospheric Research What is a risk? Two uses 1. In general language 2. A specific operational meaning

34. Atmospheric Research Characterising risk Risk is a combination of hazard, likelihood and vulnerability, i.e. stress, how likely that stress is, and how much damage that stress will cause.

35. Atmospheric Research Natural hazards approach to risk Fixed climate hazard - e.g. 1/100 flood, hurricane. Likelihood - frequency of occurrence; likelihood that it will occur Vulnerability - damage incurred Risk = f(hazard*likelihood, vulnerability)

36. Atmospheric Research Natural hazards approach to risk Examples Heat stress - hastened mortality per 10 3 or 10 5 population Flood damage mapping (e.g. $$ damage or dwellings inundated per 100 year flood) Storm damage mapping (structural damage for a given windspeed in $$ or no. of buildings damaged) Disease mapping (vector density aligned with infection rates) ENSO frequency and intensity aligned with known hazards

37. Atmospheric Research Vulnerability-based approach to risk Level of climate associated with given level of harm, e.g. critical threshold Likelihood - frequency of occurrence; likelihood that it will occur Risk = f(hazard*vulnerability, likelihood)

38. Atmospheric Research Example - water supply for irrigation and wetland management Macquarie catchment - Australia Climate baseline: Daily P and Ep data 1890-1996 infilled across the catchment Management reference: 1996 infrastructure and catchment management rules Irrigation water allocation is capped and supply is shared between irrigation and environmental flows through the Macquarie Marshes Thresholds Supply of 350 GL into the Macquarie Marshes for waterbird breeding Irrigation water allocation of 0%, 50% or 100%

39. Atmospheric Research Simulated flow into the Macquarie Marshes - baseline case

40. Atmospheric Research Simulated flow into the Macquarie Marshes -10% flow (IS92c HCM3)

41. Atmospheric Research Simulated flow into the Macquarie Marshes -10% flow (IS92c HCM3)

42. Atmospheric Research Simulated irrigation allocations baseline and -10% flow (IS92c HCM3)

43. Atmospheric Research Simulated irrigation allocations baseline and -10% flow (IS92c HCM3)

44. Atmospheric Research Sensitivity analysis for Burrendong Dam storage Exceeding critical threshold 0 10 20 -10 -20 -30 -40 0 5-5 0 5 10 15 -10 Rainfall change (%) Potential evaporation change (%) IS92c HCM3

45. Atmospheric Research Sensitivity analysis for Burrendong Dam storage 0 10 20 -10 -20 -30 -40 0 5-5 0 5 10 15 -10 Rainfall change (%) Potential evaporation change (%) Exceeding critical threshold Wettest (SRES) Driest (SRES)

46. Atmospheric Research Changes to MAF for 9 models in 2030 (%) Based on IPCC 2001 B1 at 1.7°C 0.55°C A1 at 2.5°C 0.91°C A1T at 4.2°C 1.27°C

47. Atmospheric Research Changes to Burrendong Dam storage 2030 <60 <70 <80 <90 <95 <100 <50 Cumulative Probability (%)

48. Atmospheric Research Probabilities of flow changes - impacts view Range of possible outcomes

49. Atmospheric Research Basic principles Pay greater attention to recent climate experience. Link climate, impacts and outcomes to describe the coping range. Address adaptation to climate variability and extremes as part of reducing vulnerability to longer-term climate change. Assess risk according to how far climate change, in conjunction with other drivers of change, may drive activities beyond their coping range. Focus on present and future vulnerability to ground future adaptation policy development in present-day experience. Consider current development policies and proposed future activities and investments, especially those that may increase vulnerability.