Transcript Representing Uncertainties & Selecting Scenarios

Coping with Climate Risk
climate sensitivity, coping ranges and risk
AIACC Training Workshop on Adaptation and Vulnerability
TWAS, Trieste
June 3-14 2002
Roger N. Jones
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
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
Atmospheric Research
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?
Sector
Sensitivity to what?
Water
Rainfall variability, flood, drought
Agriculture
ENSO, flood, drought, cool/hot
extremes, storms
Health
Hot/wet conditions, temperature
extremes, violent storms, floods, crop
and water shortages
Coasts
Storm surges, wind/wave climates,
pressure extremes, tidal extremes
Biodiversity Fire, flood, drought, storms
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Extreme temperature
Maximum Temperature (°C)
45
40
35
30
25
20
0
25
50
75
100
Days
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Heat Stress (Degree Days >35°C)
Extreme temperature
35
30
25
20
15
10
5
0
0
25
50
75
100
Days
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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
Atmospheric Research
Types of extreme climate events
Description
Variable
Measure
Exceeding critical
level on a continuous
scale
Extreme rainfall
Temperature
Frequency
Return period
Sequence
Duration
Complex Weather events
events
combining multiple
variables and/or
resulting in multiple
impacts
Tropical cyclones
ENSO events
Drought
Frequency 
magnitude
Severity of
impacts
Singular
events
Cessation of deep- Probability 
ocean circulation
magnitude of
Ice sheet collapse impact
Type
Simple
events
A possible future
climatic state with
potentially extreme
outcomes
Atmospheric Research
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)
High confidence
Low confidence
Very low or unknown
Rapid or non-linear change (e.g.
disintegration of the West Antarctic Ice
Sheet)
Atmospheric Research
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
Climate
system
Impacted
activity
Socioeconomic
system
Current
climate
Current
adaptations
Future
climate
Future
adaptations
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IPCC 1994
1
DEFINE PROBLEM
2
SELECT METHOD
3
TEST METHOD/SENSITIVITY
4
SELECT SCENARIOS
5
ASSESS BIOPHYSICAL IMPACTS
ASSESS SOCIOECONOMIC IMPACTS
6
ASSESS AUTONOMOUS ADJUSTMENTS
7
EVALUATE ADAPTATION STRATEGIES
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
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 socioeconomic and biophysical factors
Atmospheric Research
Coping range under current climate
Stationary Climate
& Coping Range
Vulnerable
Coping
Range
Vulnerable
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Coping range under current climate limited ability to cope
Stationary Climate
& Coping Range
Vulnerable
Coping
Range
Vulnerable
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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
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)
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
Atmospheric Research
Changing coping range socioeconomic change
Stationary Climate
Coping Range
reducing
Vulnerable
Coping
Range
Vulnerable
Stationary Climate
Coping Range
increasing
Vulnerable
Coping
Range
Vulnerable
Atmospheric Research
Changing coping range response to climate stress
Stationary Climate
Coping Range reducing
due to climate shocks
Vulnerable
Coping
Range
Vulnerable
Stationary Climate
Coping Range increasing
due to climate shocks
Vulnerable
Coping
Range
Vulnerable
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Future climate - no adaptation
Stationary Climate
& Coping Range
Changing Climate
Vulnerable
Coping
Range
Vulnerable
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Future climate with adaptation
Stationary Climate
& Coping Range
Changing Climate
Vulnerable
Adaptation
Coping
Range
Vulnerable
Planning Horizon
Policy Horizon
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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
Socioeconomic
(simple to complex)
(usually complex)
•
•
•
•
•
•
•
•
•
•
Tropical cyclone
Coral bleaching
ENSO event
Island formation
Island removal
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
2000
Election cycles/profit & loss
Agriculture (whole farm planning)
Plant breeding (new crops)
2020
2040
Forest lease agreements
Pulp plantations
Generational succession
New irrigation projects
Coastal/tourism infrastructure
Tree crops
National parks
Airport design life
2060
Large dams
Major urban infrastructure
2080
Intergenerational equity
2100
Long-term biodiversity
Bridge design life
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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)
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)
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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(hazard*likelihood, vulnerability)
Atmospheric Research
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
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)
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%
Atmospheric Research
Simulated flow into the Macquarie
Marshes - baseline case
Total Annual Flow
2.E+06
2.E+06
Bird
breeding
threshold
1.E+06
5.E+05
0.E+00
1890
1910
1930
1950
1970
1990
Year
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Simulated flow into the Macquarie
Marshes -10% flow (IS92c HCM3)
Total Annual Flow
2.E+06
2.E+06
1.E+06
Critical period
Bird
breeding
threshold
5.E+05
0.E+00
1890
1910
1930
1950
1970
1990
Year
Atmospheric Research
Simulated flow into the Macquarie
Marshes -10% flow (IS92c HCM3)
Total Annual Flow
1.E+07
1.E+06
Bird breeding threshold
1.E+05
1.E+04
100
52%
80
60
44%
40
20
0
Percent
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Simulated irrigation allocations
baseline and -10% flow (IS92c
HCM3)
100
Flow (Gl x 10)
80
60
40
20
0
1890
1910
1930
1950
1970
1990
Year
Allocations
Alloc - 10%
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Simulated irrigation allocations
baseline and -10% flow (IS92c
HCM3)
80
60
40
56%
51%
31%
22%
1%
6%
20
0
100
80
60
40
20
Annual Irrigation Allocation (%)
100
0
Percent
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Sensitivity analysis for Burrendong
Dam storage
Potential evaporation change (%)
15
-40
-30
-10
-20
Exceeding
critical
threshold
0
10
5
10
0
IS92c HCM3
20
-5
-10
-5
0
5
10
Rainfall change (%)
Atmospheric Research
Sensitivity analysis for Burrendong
Dam storage
Potential evaporation change (%)
15
-40
-30
-10
-20
Driest (SRES)
Exceeding
critical
threshold
Wettest (SRES)
0
10
5
10
0
20
-5
-10
-5
0
5
10
Rainfall change (%)
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Changes to MAF for 9 models in 2030 (%)
Based on IPCC 2001
Low
Mid
0
0
-8
-8
High
0
-10
-16
-16
-20
-24
-30
B1 at 1.7°C
0.55°C
A1 at 2.5°C
0.91°C
A1T at 4.2°C
1.27°C
Atmospheric Research
Potential evaporation change (%)
Changes to Burrendong Dam storage
2030
Cumulative
Probability (%)
15
-40
-30
-10
-20
<100
0
10
<95
5
10
<90
<80
<70
0
20
<60
-5
<50
-10
-5
0
5
10
Rainfall change (%)
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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.
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