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Scenarios andDecision Support Systems
Monika ZurekFAO, Rome
Greg KikerUniversity of Florida
GECAFS Caribbean Meeting, 30 Aug 05
Overview of the talk
Looking into the future
What are scenarios? Why use scenarios?
Decision Support Systems
The GECAFS scenarios component
Looking into the future
Out of curiosity
For scientific exploration
For decision-making
Decisions are based on expected outcomes and the
trade-offs they imply Decisions involve uncertainty about how the future will
unfold
For planning purposes/strategic planning exercise
Sources of Uncertainty when thinking about the Future
Ignorance
Understanding is limited
SurpriseThe unexpected and the novel can alter directions
VolitionHuman choice matters
Source: P. Raskin
Methods for looking into the future
Predictions are seen by the public and decision makers as things that will happen no matter what they do.
Forecast is the best estimate from a particular method, model, or individual.
Projections are heavily dependent on assumptions about drivers and boundary conditions; they often assume that these will not change. Projections lead to "if this, then that" statements.
Scenarios……
Cau
salit
y
Uncertainty (data availability)
Projection
Scenarios, predictions & projections?
What if?
Scenarios
The probability that …
PredictionF
acts
low high
unknown
known
Source: modified after R. Leemans 2003
Cau
salit
y
Uncertainty (data availability)
Projection
Scenarios, predictions & projections?
What if?
Scenarios
The probability that …
Prediction
The probability that …
PredictionF
acts
low high
unknown
known
Source: modified after R. Leemans 2003
Scenario Definitions
Plausible stories about how the future might unfold from existing patterns, new factors and alternative human choices. The stories can be told in the language of both words and numbers (Raskin, in press).
Plausible descriptions of how the future may develop, based on a coherent and internally consistent set of assumptions about key relationships and driving forces (Nakicenovic 2000).
A tool for ordering one’s perceptions about alternative future environments in which one’s decision might be played out (Schwartz 1996).
Plausible alternative futures, each an example of what might happen under particular assumptions (MA).
Why use scenarios?
Purpose of scenarios:
Information dissemination Scientific exploration Decision-making tool
Understanding all factors influencing the future Robust strategies that work under different worlds
Different process of stakeholder involvement in scenario development
Understanding and communicating the main assumptions on which people base their notion of the future
‚Good‘ scenarios should ...
... be plausible (or ‘not implausible‘)
... be internally consistent and coherent
... be constructed with rigour, detail & creativity
... meet the goals of scenario exercise!!!
Decision Support Systems
Many definitions, many visions, many versions…
DSS Integrate Tools Models Databases Visualization (GIS, graphics, charts…) Decision analysis (MCDA, trade-off analysis,
linear programming)
Spatial Maps of Ecosystem Indicators
User-Defined “Slow and Fast”
Time Steps Management Options
“Warning Lights”
Tabbed panes with several time series charts
Mouse-driven Chart and Text
Display
Reset Button
Example DSS: QnD System
Challenges in Building DSS
DSS almost always focus on one sector’s (or discipline’s) tools and concepts
Model integration is difficult and technically challenging
Not helpful in unearthing assumptions Transparency versus Ease of Use Integration with scenario planning -
“More gaps than links”
CARSEA Scenarios • Neo-Plantation Economy• Quantity Over Quality• Growing Asymmetries• Diversify Together
Tourist visits, foreign investment, external prices, etc.
Climate Scenarios • Precipitation• Hurricane Intensity/ Frequency• Sea Level Rise
QnD:Jamaica Version 0.0
• Stochastic relationships• Time series values• Incremental change
Socio-Economic Drivers
Climatic Drivers QnD Scenarios
• Neo-Plantation with mild Climate Change• Neo-Plantation with intense Climate Change• Etc…
GECAFS – research focus
1. Classifying and characterizing the major food systems existing today for GEC studies,
2. Investigating the vulnerability of existing food systems to GEC and its consequences for different parts of society,
3. Sketching plausible future changes in environmental and socioeconomic conditions that will effect food systems,
4. Based on the analysis of plausible futures, devising decision support systems for the formulation of diverse policy-instruments to adapt global food system to GEC.
Scenarios Component Research Questions
What are plausible future changes in environmental and socio-economic conditions that will affect food systems?
What elements of global scenarios are most important for regional-level food system analyses?
How best can global scenarios be linked to the regional scale in order to capture regional-level factors relevant to food systems?
Linking global and regional scenario exercises
Global Scenarios
IGP CAR SAF
Preparatory phaseFeedback
Regional GECAFS Scenarios