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New Zealand Climate Change Research Institute 1
Changing Climate Risk
Decision-making under uncertainty
Auckland Council 14 June 2012
Judy Lawrence
Adjunct Research Associate
NZ Climate Change Research Institute Victoria University of Wellington
Decision-making under uncertainty for climate change
Decision context and frameworks
Tools and outcomes
Some examples
Decision analysis
A strategic approach
Perceptions of risk
Adaptive responses
Necessary conditions
Responses under diverging climate futures and different timelines
Use incremental adaptation to changes over timeframes that are reasonably certain and where flexibility to change is possible
BUT also plan increasingly for divergent possible futures and transformative adaptation
THIS MEANS that the lifetime of the adaptation decision relative to the rate of change is KEY in determining the type of response
2000 2020 2040 2060 2080 2100 2120 2140
0
500
1000
1500
SLR
(m
m)
Year
Permanent Infrastructure Settlements
Election cycles
Regional district plans
2112
2012
Residential housing life
Long term plans
Coastal hazard zones
Resource consent Protection works
Time
Different decisions
Static responses reduce flexibility and have limits
‘Hard’ protection—static and time limited e.g. Kapiti coast
‘Setback’ lines—static and time limited e.g. Hawkes Bay coast
Raised floor levels—temporary to a fixed limit e.g. Kapiti coast
Removable houses – practically limited e.g. Kapiti
Ground water pumping – time and capacity limited e.g. Kilbirnie, Wellington and South Dunedin
More flexible responses have been tried
‘Soft’ protection–dunes, wetlands restoration e.g. Bay of Plenty
Integrated flood plain, wetlands and community outcomes e.g. Twin Streams, Waitakere
Progressive controls on existing uses based on coastal hazards gives moderate flexibility– transitional, time limited e.g. Canterbury, Hawkes Bay
Retreat planned over a longer time frame – rarely used and only after repeat climate ‘events’
Successful retreat from a floodplain Twin Streams Waitakere Auckland New Zealand
How did the council get 78 property owners to agree to sell? They linked the managed retreat project to wider community goals and outcomes
They used consistent messaging They shared information and explained the problem
They combined technical and people skills to communicate to property owners They demonstrated genuine care and respect for affected property owners
IMPORTANTLY they had a bucket of money for land purchase.
2000 2008
Practice outcomes
Constrained precaution
Short-term focus
Demand for ‘Give us a number’
Use of ‘Best estimates’
Static responses
Lock-in and increasing risk
Potential for maladaptive
decisions
These constrain flexible decision options
Changing frequencies for extreme events
0%
10%
20%
30%
40%
Pro
babili
ty o
f occurr
ence
originally 5%
originally 2%
originally 1%
Time
Rate of change in probability of occurrence as probability distribution changes. Based on a recent summary of global temperatures by Hansen (2011). Some changes are already about one third to one half of the way along the time axis.
Hutt Valley Flooding case study
Projected flooding changes
More frequent with protection standards of existing and planned measures degrading and a large uncertainty range
Uncertainty conflicts with quest for ‘robust’ definitive guidance BUT averages or best estimates can mislead
Lower warming scenarios currently 1% likely each year will become 2.5% likely by 2100 and for higher warming scenarios 1% is likely to become 6% likely by 2100
Changes in flood frequencies under the A2emission scenario. The black dots and line show present-day flood volumes and their estimated return periods. The purple dots show best estimate future flood volumes and return periods under continued global emissions increases. The purple band shows the 10 to 90% range across different climate models. The light pink band shows the lowest and highest results across all models.
Hutt Valley Flooding case study
Impacts of flooding
Flood impacts increase non-linearly beyond 2300 cumecs with increasing flood volumes and more properties damaged to greater depths
Flood impacts can have a disproportionate impact on different social groups
Ability to adapt, cope and recover from flooding
Understanding of flood risk was low over Hutt Valley
Past experience increases household preparedness and willingness for flood protection
The framing of risk, affects understanding of the likelihood and severity of flood risk and level of preparedness e.g. ARI, AEP and chance – can lead to maladaptation
Households prefer a region-wide integrated flood risk management regime, and land use planning over structural measures
Hutt Valley Flooding case study
Barriers to adaptive capacity
Lack of integration and strategic oversight within and between levels of government
Leadership needed for integration and central government direction could influence long term risk management
How risk is communicated—AEP and ARIs are misinterpreted
Different risk assessment approaches across the region
Mismatch of timeframes across council functions
Dominant focus on costs rather than who pays and when
Opportunities for adaptive capacity
Pool resources across levels of government
Apply LIDAR for better elevation data
Use visual media of past flood damage Share learning via workshops
Communicate risk as changing over
time
Use of flood information showing flooding over a defined common floor level for a range of scenarios
Integrate climate change across all
council functions
Decision frameworks
BAU approaches limited by capacity to adapt to changing risk- limit to adaptation
Consideration of a wide range of options for different magnitude and frequency of changes over different timeframes
Continuous transformation will be more appropriate
Flexible decision pathways needed to
bridge from incremental adaptation within current frameworks, to a transition to learning and re-orienting as the future climate unfolds
Implications for responses
Decision analysis
Sensitivity to change Planning process Reducing risk
Short versus long term
planning issues
Extent of the exposure to
climate risks
Capacity to deal with rates
of change in exposure
Incremental adaptation
to transformation
Precautionary risk
management
Ranges of options for
different decisions
Monitoring changes to
provide advance
warning
Regularly assessed as
still inside a risk
envelope
Advance warning of
thresholds for
structural change
Scan exposure and sensitivity across
region
What is at risk and when over lifetime
Implications of BAU -different timeframes
and range of scenarios
Options over a range of scenarios
Stage actions for different
consequences
A strategic approach
Undertake in a deliberative manner
A decision-makers focus
A new approach for decision makers - Netherlands
From high levels of protection to risk management
Instead of starting with climate scenario an adaptation tipping points approach is used.
“what are the first issues that we will face as a result of climate change and when can we expect this ?”
How long will current strategies be effective and thus when will alternative strategies be needed?
Kwadijk, J.C.J., et al., 2010: Using adaptation tipping points to prepare for climate change and sea level rise: a case study in the Netherlands. Wiley Interdisciplinary Reviews: Climate Change, 1(5), 729-740.
Perception of risk and its communication
Cognitive biases occur in all processes—Optimism bias; fear response; influence of hazard/risk experience on over and under estimating risk; effect of gains and losses
Animation and visual images over a range of scenarios on different response options work best Takaka flooding, Wellington City SLR
Communication of risk probability enhanced if use 1 in 4 chance of an event of X size in next 30 years—much research to support this
Community conversations build trust if good information and consistent messages Kapiti, Hawkes Bay
Risk framing and communication—recent research
Information is important
Problem appears more immediate
Greater trust in council
People are more willing to take personal action and support council action
Timeframe focus is important
Focus on medium distance (2050) and
extreme events may emphasize nearness of the threat
Medium focus (2050) may improve trust in council action
Extreme projections may increase perceived necessity of adaptation
Laurel Evans 2012. Psychology Department VUW. Preliminary results of a Survey on Perceptions of Sea Level Rise
Some adaptive responses options
Develop Plans B and C and...which can be ready and waiting depending on outcomes
Monitor BAU with triggers for review e.g. rate of change accelerates; hazard event
Reversible and less risky options e.g. soft options like reserves and parks
Extra safety margins where cheap to do so and lock-in avoided
Risk hedge e.g. different responses in different places or wider base to stopbanks for future raising
Shorter life of infrastructure can be changed in future at lower cost
Transformation e.g. retreat, identify alternative land, resources, change governance arrangements
Necessary conditions
Processes for:
Sharing understandings of risk with communities of interest
e.g. insurers, valuers, real estate, lawyers, banks and the wider community
Engaging continuously with the communities affected, building on their experience
Weighing and comparing options that do not under-estimate future benefits
Discuss ‘who pays’ and ‘when’
Monitoring decision outcomes
over time
Reviewing decisions for continuous adaptation that manages property ownership expectations
Addressing ‘fairness’ of outcomes and dissent
Alignment between levels of government
BUT these all rely on continuity of institutions over time and political commitment
Some windows of opportunity
Regular planning and budgetary processes
o Annual plans
o Asset management plans
o Regional and district plan reviews and variations
Replacement or upgrade of infrastructure
After damaging weather-related and earthquakes events
When organisational change takes place –integration across functions
Community communication opportunities & consultations
BUT the mainstream is limited
Key issues
Increasing rate of change and dynamic nature of climate changes means
Current decision frameworks and practice entrench risk, constrain future flexibility and limit adaptation
Mainstreaming has limits
Strategic decisions are needed before thresholds are reached
Transitions will take place over decades
Shift from static incremental practice to continual deliberation, adaptation, transitions and planned transformations
Unbundling different types of decisions by different timeframes
Alignment of all levels of government, private property owners and communities working together in a deliberative process
Experimentation with flexible decision pathways will become mainstream
BUT continuity of institutions and political commitment required