Environmental Scenario Analysis Overview and Approaches

1. Environmental Scenario AnalysisOverview and Approaches Thomas Henrichs European Environment Agency

2. Overview & Approaches ... Definitions of scenarios Elements of scenarios Goals of scenarios Types of scenarios How may scenarios Developing & Analysing scenarios Good scenarios

3. Many different definitions exist ... • “A scenario is a sequence of events especially when imagined; especially: an account or synopsis of a possible course of action or events.” (Merriam-Webster Dictionary On-line, 2003) • “Scenarios are hypothethical sequences of events constructed for the purpose of focussing attention on causal processes and decision points.” (Kahn and Wiener, 1967) • “Scenarios are descriptions of journeys to possible futures. They reflect different assumptions about how current trends will unfold, how critical uncertainties will play out and what new factors will come into play. (UNEP, 2002)

4. Definition of scenarios (EEA) scenario … a plausible description of how the future may unfold based on a set of 'if-then' propositions. A typical environmental scenario includes a representation of the initial situation and a storyline that describes the key driving forces and the changes that lead to an image of the future. Note that scenarios are neither predictions nor forecasts.

5. Elements of scenarios • Current State • situation in the base year of scenario • Driving forces • deteminants that influence changes • choices/decisions that bring changes • (Step-wise) Changes • at the core of a scenario analysis • depicting how the driving forces unfold • storyline highlighting key features • Image(s) of the future • situation in the end year of scenario

6. Types of environmental scenarios • Exploratory vs Anticipatory Scenarios exploratory scenarios • present -> future • to explore uncertainties/driving forces/developments • to test impacts of implementing specific policies antipatory scenarios (also ‘normative’ scenarios) • present <- future • to investigate how specific end state can be reached • to show how to achieve environmental targets

7. Types of environmental scenarios • Baseline vs Alternative Scenarios baseline scenarios (also ‘reference’ scenarios) • describe a future development / state in which no new policies or measures are implemented apart from those already adopted or agreed upon alternative scenarios (also ‘policy’ scenarios) • take into account new policies or measures additional to those already adopted or agreed upon and/or that assumptions on key driving forces diverge from those depicted in a baseline scenario

8. Types of environmental scenarios • Qualitative vs Quantitative Scenarios qualitative scenarios • are narrative descriptions of future developments • (i.e. presented as storylines, diagrams, images, etc.) quantitative scenarios • are numerical estimates of future developments • (i.e. presented as tables, graphs, maps, etc.) • usually based on available data, past trends and/or mathematical models

9. Goals of environmental scenarios • Education / Public Information • to educate and teach students, citizens, pupils • to raise awareness of policy-makers, stakeholders • Science / Research • to integrate information from different fields • to explore possible developments • Strategic Planning / Decision Support • to gather different views and to identify issues • to frame strategic issues, to identify alternatives • to support policy measure development

10. How many scenarios? • As many as possible • … to represent the many views of the future • … to represent the many options of the future • As few as necessary • … to avoid scenario fatigue • … to make the process ‘handable’ • Large projects with complex scenarios often aim for 2 to 4 scenarios Based on: EEA (2001)

11. EEA Experts Stakeholders Qual. Scen ☺Floods ☺ Biodiv. … European Land Use Change Scenarios The main driving forces behind land use change are climate change, population growth and technical and economic development, particularly of the transport and agriculture sectors. The environmental impacts of land use change are complex, and may affect air quality, water quality and quantity, landscape structure and biodiversity … Combining approaches ‘Story-and-Simulation‘ Quant. Scen. Data & Modelling Group(s) Based on: EEA (2001)

12. Option 2:First agree on a set of global scenarios, then develop local and regional scenarios. Revisit global scenarios Global–Local level integration • Option 1:Develop global and local scenarios in parallel / iteratively Global-Level Scenarios Regional-level Scenarios Level of Detail Local-level Scenarios

13. What are good scenarios? 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!!!

14. EEA environmental scenarios portal http://scenarios.ewindows.eu.org • Web Portal • EEA Reports • Links to • institutions • networks • studies • Resources • News • Glossary • Bibliography