Scenarios Emily McKenzie 2 April, InVEST Introductory Seminar, Bangkok.
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Transcript of Scenarios Emily McKenzie 2 April, InVEST Introductory Seminar, Bangkok.
Total values often less meaningful
• Bermuda’s reefs worth– $722 million p.a.– 10-17% of GDP
But what would be costs and benefits of new shipping channels?
What are scenarios?
• Plausible, simplified, descriptions of future
• Based on coherent & consistent assumptions:
– key drivers– their relationships– their impacts on
ecosystems
Despite their importance, environmental services are not normally included in resource decisions.
This is sometimes because it is hard to compare the benefits and costs of different options.
Why Use Scenarios?
Example of Scenarios
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Kakawis
OpitsatYarksis
Clayoquot
Tofino
Compare options
") Additional Floathomes
") Existing Floathomes
Oyster Aquaculture
Eelgrass
Types of scenarios
• Interventions– Designs for policies, plans and projects
• Explorations– Possible but unexpected futures
• Visions– Perceptions of desirable or undesirable futures
• Projections– Depictions of the expected future
Yesterday
Today Tomorrow
The Future?
Interventions
Net benefitsfrom coastal
ecosystem
Time
Net benefitsfrom coastal
ecosystem
Time
Benefitswith MPA
MPA implementation
Cost of MPA
Benefits without MPA
Costs ofmanagement
Benefits of management
Depictions of how additional, new interventions could be implemented, such as policies, projects or plans.
Explorations
• Explore possible future developments. • Anticipate unexpected future circumstances, test how policies cope with change.
Visions & Projections
Visions: Subjective depictions of possible futures that vary according to their desirability.Projections: Depictions of the expected future, without new interventions
Why use scenarios?
• Identify tradeoffs• Consider new policies• ‘Future-proof’ policies• Air conflicts, develop consensus• Learning• Storytelling
Scenarios for InVEST need to:
• Describe a possible future
• Reflect uncertain developments or choices
• Be spatially explicit (or can be)
Scenarios for InVEST
• Scenarios as maps of land cover and/or coastal and marine habitats and uses.
• Scenario maps feed into InVEST to produce maps of ecosystem services for each scenario.
Conservation 2025
Current
BAU 2025
Confidential draft, Feb 2009Thanks to Dr Ruth Swetnam
Comparison of carbon storage and sequestration in different scenarios…
2000 Conservation2025
BAU 2025
2.419 t/C
-8.65 7 t/Cor -3.6% of 2000 value -31.617 t/C
or - 13% of 2000 value
LOSS LOSS
Confidential draft, Feb 2009Thanks to Dr Ruth Swetnam
Scenario Development Methods
Bringing together multiple methods:• Qualitative: narrative stories of future
– Multi-stakeholder community visioning– Hand-drawn maps
• Quantitative: numerical estimates of future– Landscape optimization modeling – Computer-based land transition models
Methods in Tanzania
– Compare ecosystem service outcomes with ‘hopeful future’ (poverty alleviation policies) versus business as usual.
– Methods: qualitative + quantitative– Time: 1 year – Capacity: 2 coordinators– Participation: high, multiple stakeholder workshops
Step 2: Select the right scenario approach
Step 3: Develop scenario storylines
Step 4: Create scenario maps
Step 5: Assess ecosystem service outcomes
Step 6: Use and communicate results
Step 1: Understand scenarios
Key steps
Drivers• any natural or human-induced factor that directly or
indirectly causes a change in an ecosystemRules• principles or conditions that prescribe how changes will
occur in the future
Others • Timeframe• Spatial scale & extent
Key Elements
Drivers
• Social and demographic– E.g. population growth
• Technological– E.g. innovation
• Economic– E.g. commodity prices
• Environmental – E.g. climate change
• Political– E.g. Land tenure
Scenario drivers in InVEST
• Terrestrial and freshwater– Land cover or land use (e.g., agriculture)– A change in management practices (e.g., crop type)– Other assumptions (e.g., how far people are willing to travel
to harvest a forest product)
• Marine InVEST– Human uses of the coast and ocean (e.g., fishing)– Coastal and near-shore habitat distribution– Coastal development– Land cover or land use
Converting storylines into maps
• Drawing maps– Work with stakeholders to draw a map for each scenario
using paper, digital or online mapping tools
• Trend analysis– Use past experience and statistical methods to predict where
change is most likely to occur on the landscape or seascape.
• Rule-based approaches– Use rules based on social, economic or biophysical principles
that define which areas are likely to be most suitable for particular uses or activities
Aspects of LC change rules must reflect
• Type of LC change– e.g. conversion from forest to agriculture
• Magnitude and time frame of LC change– e.g. 15% over 10 years
• Spatial and temporal dimensions of LC change– e.g. forests bordering agriculture are converted first
Types of rules
• Biophysical rules– Climate, e.g. rainfall – Topography, e.g. slope, elevation – Soil, e.g. type, depth
• Socio-economic rules– Accessibility, e.g. infrastructure, population density – Governance, e.g. land tenure, protected areas – Demography, e.g. poverty, education
• Threshold rules, e.g. LC expands at < 2,000 meters altitude• Location rules, e.g. LC expands in forest reserves• Rate rules, e.g. LC expands at historical rate until 2015 then slows • Toggle rules, e.g. LC does not expand in protected areas
Characteristics of effective scenarios
• Relevant• Legitimate• Plausible• Understandable• Distinct• Surprising• Scientifically credible• Comprehensive
• Iterative• Participatory
Photo credit: Josh Goldstein
• Scenario Development Guide– Picking the right scenario– Creating storylines, turning storylines into maps– NatCap case studies
• Scenario Generator – Simple, rule-based approach– % change from storylines
• InSEAM– Online collaborative map drawing software
• IDRISI Land Change Modeler– Around a dozen land cover transitions– Rules and constraints, taking into account historical trends
NatCap scenario tools
Common challenges
• Knowing why and how to start • Selecting the right approach• Engaging stakeholders effectively• Finding data• Creating contrasting scenarios• Settling with compromise
Central Sumatra Today
Sumatra Ecosystem
Vision
Government spatial plan
Sumatra
(60% more forest than
2008)
Same amount of natural
forest as 2008 (but likely
worse)
Issues of concern:-Effects of forestry and other industrial activities on aesthetic views-Effects of shellfish harvest and aquaculture on sensitive habitats