Transcript Methods and Tools - IPCC WG II, Chapter 2

Methods and Tools - IPCC TAR
WGII (Chapter 2)
Gary Yohe
Professor of Economics
Wesleyan University
June 11, 2001
QUESTIONS RAISED IN THE CHAPTER
• Detecting the current effects of climate change (and
climate variability)
• Anticipating, estimating, and integrating future effects of
climate change (and climate variability)
• Valuing and costing impacts and adaptations
• Expressing and characterizing uncertainties
• Reflecting appropriate frameworks for decision-making.
The Vulnerability Context of Adaptive Capacity
• Vulnerability (a vector V) is a function of exposure (to
multiple stresses - a vector E), sensitivity (a similarly
dimensioned vector S), and adaptive capacity (A); so:
V = F{ E(A); S(A) }
• Adaptive capacity may be quantified to a scalor, but it has
multiple determinants Di :
A = AC {D1 , ……, D8 }
The Determinants of Adaptive Capacity
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Range of adaptation options
Availability and distribution of resources
Structure of institutions and decision-making processes
Stock and distribution of human capital
Stock of social capital
Access to risk spreading processes and mechanisms
Ability to process information and the credibility of
decisions
• Public perception of exposure, sensitivity and attribution
Site Specificity and Path Dependence The Scale of Determinants
• Applicable options are determined on a micro scale, but
the list of possibilities may come from macro-scale
processes like this one
• The next 5 determinants have macro-scale roots, but
micro-scale manifestations:
Resources and their distribution
Institutional structure; decision-making
Human capital
Social capital
Access to risk spreading
Scale Considerations, Continued
• Information management may have macro-scale
foundations, but it has fundamental micro-scale import.
• Public perception of attribution should similarly be
determined on a micro-scale even if there are influences
from outside and potential sources of information have a
macro scale. The issue is credibility and when micro-scale
actors look for credible information.
Implications for the Adaptation Methods and the
Policy Framework
• The local implications of macro-scale determinants are
their most important characteristics, and working the links
across scales can add clout by expanding the scope of
influence.
• The effects of most if not all of the determinants of
adaptive capacity can be traced through their implications
for specific adaptation options.
• Assessing overall vulnerability through organized and
determinant-based considerations of the abilities of
available options to influence sensitivity or exposure could
be a very effective foundation for a methods and policy
frameworks.
Adaptation Options and Coping Capacity
• The critical link in each context can be the definition of
thresholds that define the boundaries of coping capacity
against variability in the local environment.
• It follows that exploring how each option might be able to
change those thresholds or variability to influence
exposure and/or sensitivity is critical.
• The roles of other determinants in impeding or enhancing
those abilities must also be recognized.
• And systematic interactions across determinants and
adaptation options cannot be ignored.
Returning to the Questions
• Detection informs our understanding about exposure and
sensitivity.
• Anticipation, estimation and integration of future
effects does the same:
Anticipation takes detection into the future to
identify stresses.
Estimation adds detail to characterizations of the
future.
Integration brings the interactions of multiple
stresses into focus.
Integrating Multiple Stresses
• Some stresses have common sources - another place where
macro scale processes can be identified and exploited.
• Other stresses have different sources, but are they
positively or negatively correlated? Or are they
independent?
• Looking endogenously for anthropogenic sources can
highlight new suites of adaptive options.
More on the questions
• Valuation and costing impacts and adaptations play into
evaluations of options, but currency is not necessarily the
only metric:
Schneider’s 5 metrics: monetary loss, human life
quality of life, loss of species and bioversity, and
(in)equity and the distribution of well-being;
and both can play a role in assessing the significance of
resource availability and their distribution.
More on the questions
• Uncertainty plays a role in:
Institutions - how do they cope with uncertainty?
The significance and structure of risk spreading
mechanisms.
Decision-makers and public perception - how do the
players sort the signal from the noise?
Uncertainty and Coping Capacity
• Looking at climate variability provides “early warning” to
“not-implausible futures” and abrupt impacts of climate
change.
• Focusing on the ability of adaptation options to manipulate
the coping capacity as well as variability offers a way to
include uncertainty into the analysis.
• This is the link that brings short-term planning horizons
into the context of long-term stresses like climate change.
Uncertainty and Analysts
• Notwithstanding our considerable abilities, the
output of the impact and adaptation analysis
and/or a Policy Framework must be cast in terms
of underlying uncertainty:
Ranges of possible outputs.
Representations of multiple moments.
Consideration of robustness in assessment
and adaptation.
More on the questions
• Understanding of decision analytic frameworks and
their local, path dependent application informs our
understanding of:
Institutions
Human and social capital
Positive and normative analysis of risk spreading
mechanisms
Topic Organization of Chapter 2
• Detection (species and managed systems)
• Anticipating change
• Integrated assessment
• Cost and valuation methods
• Representing uncertainty
• Decision-analytic frameworks
Questions versus Sections in Chapter 2
Sections
Detection:
Species
Managed
Detection
Future Assess
& Integrate
XXX
XXX
Anticipate
XXX
Integrated
Assessment
XXX
Cost & Value
Methods
Uncertainty
DAF
XXX
XXX
Value &
Cost
Uncertainty
Decision
Framework
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
Topics: Detection
• There are two questions of attribution:
Anthropogenic forces are changing the climate
Climate change is have an impact
• Fingerprint argument based on global congruence - a basis
of considerable controversy.
• Still, for present purposes, the second attribution critical
for framing adaptation.
• Nonetheless, the first attribution important in evaluating
future.
Anticipating Future Impacts
• Scenarios define baselines and define scales.
This is perhaps backwards for adaptation work.
• Integration in Chapter 2 tends to focus on feedbacks and
the role that vulnerability pays in pushing mitigation.
This is not the type of integration needed here.
• Attention is nonetheless drawn to climate variability and
extremes.
Exactly, and the link to adaptive capacity made.
Focus attention on variability, thresholds, coping
capacity and abrupt impacts of climate change.
Integrated Assessment
• Integrated assessment broadly defined is not necessarily
linear from beginning to end.
IA methods can help with
multiple stresses (their common sources and/or
diversity)
interactions of adaptation options
delineating the operative scales of determinants
the definition of location specifics and path
dependence.
Cost and valuation methods
• All concepts are based on the notion of opportunity cost.
• This foundation can accommodate multiple metrics.
• Costing methods can provide some answers and insights,
but not all; e.g., the cost and sources of inequity.
• Other initiatives on quantifying monetary estimates of nonmarket impacts (through direct and indirect methods) may
not be widely applicable.
• This means that cost-benefit analysis is not the only game
in town. Ultimately, though, there needs to be some
assessment of tradeoffs across values attached to specific
metrics….
This is the ultimate context for
opportunity cost. This is the ultimate
context for opportunity cost.
This is the ultimate context for
opportunity cost.
Uncertainty
Sources of Uncertainty:
Missing data or errors in data and noise.
Random sampling error and/or selection bias.
Known processes with unknown functional forms.
Known structures but unknown parameters.
Structural change over time.
Ambiguous concepts or techniques.
Spatial or temporal scale mismatches.
Humans.
Cascading Uncertainty
• This is a widely accepted notion that integration across
multiple systems amplifies uncertainty.
• Adaptation based analysis from second attribution shortcircuits some of the cascade……as long as adaptive
capacity analyses consider the robustness of that capacity
and the derivative vulnerability across a range of “notimplausible” scenarios regardless of attributed probabilities
(these may not be known; and the tails might be wide).
Decision Analytic Frameworks
• Highlights formal distinctions between:
Cost-benefit criteria.
Precautionary criteria.
Broad-based decision analysis.
Risk analysis.
Cost-effectiveness.
Policy exercises.
Adaptive capacity focus suggests that local specificity and
path dependence determine the DAG
Take-Home Messages
• Multiple tools exist, but they may not be fully adept at
handling adaptation/impacts analysis.
• While macro-scale processes work in most if not all parts
of the world, micro-scale processes are critical; and they
may not fit any specific context.
• Nonetheless, there will be common insights, common
frustrations, and common methodology.
Let many flowers bloom, and
convene periodically to compare notes,
share “war stories”, and otherwise
collaborate without the requirement of
producing a “comprehensive document.