Scenarios Emily McKenzie 2 April, InVEST Introductory Seminar, Bangkok

Outline What are scenarios? Why use scenarios? How to develop scenarios? Some examples

Tell Stories, Use Scenarios

Valuation study in Bermuda After Before

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 Compare options

Risk to Habitats

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

Interventions Net benefits from coastal ecosystem Time Net benefits from coastal ecosystem Time Benefits with MPA MPA implementation Cost of MPA Benefits without MPA Costs of management 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.

Example from Tanzania Hopeful Expectations – poverty alleviation Business as Usual

Example from Tanzania Carbon storage on the current landscape…

Conservation 2025 CurrentBAU 2025 Confidential draft, Feb 2009 Thanks to Dr Ruth Swetnam Comparison of carbon storage and sequestration in different scenarios…

2000 Conservation 2025 BAU t/C t/C or -3.6% of 2000 value t/C or - 13% of 2000 value LOSS Confidential draft, Feb 2009 Thanks 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 ecosystem Rules 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)

Hawaii

Issues of concern: -Effects of forestry and other industrial activities on aesthetic views -Effects of shellfish harvest and aquaculture on sensitive habitats

Any questions?