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?

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 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 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

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

Methods in Tanzania – High stakeholder participation – Multiple stakeholder workshops, interviews – Time: 1 year – Capacity: 2 coordinators – Policy review

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

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

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?

Scenario exercise #1 Discuss what type of scenarios will enable InVEST results to address your policy goals: – Policies, projects or plans – Unexpected future possibilities – Visions of desirable futures – Business as usual Decide how many scenarios you will develop Determine the appropriate scale and timeframe Describe each scenario as a narrative story