Coping with Climate Risk climate sensitivity, coping ranges and risk

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Coping with Climate Riskclimate sensitivity,
coping ranges and risk
AIACC Training Workshop on Adaptation and
Vulnerability TWAS, Trieste June 3-14 2002

• Roger N. Jones

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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

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Impacts are sensitive to climate variability and
extremes

• Sensitivity to climate is
• how much a system or activity is affected by
  climate-related stimuli

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Insensitive Unaffected by rain, hail, sun, wind
or snow
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Sensitive Easily affected by rain, hail, sun,
wind and snow
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Sensitivity to what?
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Extreme temperature
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Extreme temperature
Increasing stress
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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

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Types of extreme climate events
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Confidence levels

• Climate Variable
• Atmospheric CO2 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
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Modelling climate variability

• Most impacts are sensitive to climate variability
  rather than the mean (atmospheric CO2 is a
  notable exception)
• Climate models represent climate variability
  relatively poorly
• Realistic and plausible scenarios of climate
  variability are needed

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Linking climate to impacts
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IPCC 1994
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Two approaches to VA

• ?V ?I ?A
• V ? I A, t
• t 0, current climate, reference or baseline
• Time t relates to the planning horizon

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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

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Coping range under current climate
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Coping range under current climate - limited
ability to cope
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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

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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)

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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

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Changing coping range - socioeconomic change
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Changing coping range - response to climate
stress
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Future climate - no adaptation
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Future climate with adaptation
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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

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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.

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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

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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

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Planning horizons
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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)

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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)

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What is a risk?

• Two uses
• 1. In general language
• 2. A specific operational meaning

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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.

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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(hazardlikelihood, vulnerability)

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Natural hazards approach to risk

• Examples
• Heat stress - hastened mortality per 103 or 105
  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

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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(hazardvulnerability, likelihood)

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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

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Simulated flow into the Macquarie Marshes -
baseline case
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Simulated flow into the Macquarie Marshes -10
flow (IS92c HCM3)
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Simulated flow into the Macquarie Marshes -10
flow (IS92c HCM3)
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Simulated irrigation allocations baseline and
-10 flow (IS92c HCM3)
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Simulated irrigation allocations baseline and
-10 flow (IS92c HCM3)
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Sensitivity analysis for Burrendong Dam storage
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Sensitivity analysis for Burrendong Dam storage
Driest (SRES)
Exceeding critical threshold
Wettest (SRES)
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Changes to MAF for 9 models in 2030 ()Based on
IPCC 2001
A1T at 4.2C 1.27C
B1 at 1.7C 0.55C
A1 at 2.5C 0.91C
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Changes to Burrendong Dam storage 2030
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Probabilities of flow changes - impacts view
Range of possible outcomes
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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.