1 HOW SCALE MATTERS: SOME CONCEPTS AND FINDINGS Thomas J. Wilbanks Oak Ridge National Laboratory USA Prepared for the Millennium Ecosystem Assessment Workshop on Bridging Scales and Epistemologies in Multiscale Assessments Alexandria, Egypt March 2004

2 This Presentation Will Briefly: Step out from an overarching intellectual challenge across the sciences: to understand relationships between macrocale and microscale phenomena and processes Summarize some (more or less) theoretical concepts related to how scale matters in conducting large, integrative nature-society assessments Consider issues related to both:  How phenomena and processes differ between scales  How phenomena and processes at different scales affect each other

3 Consider Some Basic Concepts: Arrayed along a scale continuum, most processes establish certain dominant frequencies: a kind of lumpiness, organizing themselves more characteristically at some scales than others Recognizing this “lumpiness,” we can concentrate on scales related to particular levels of system activity (e.g., family, neighborhood, city, region, and country) and, at any particular level, subdivide space into a mosaic of “regions”

4 Consider Some Basic Concepts (contd.): In many (most?) cases, smaller scale mosaics are nested within larger scale mosaics; therefore we can often think in terms of spatial hierarchies In some (many?) cases, there are relationships between spatial and temporal scales As we look across scales, the salience of external linkages increases as the scale shrinks Place is more than an intellectual and social construct; it is a real context for communication, exchange, and decision- making

5 Consider Some Basic Concepts (contd.): Integrative research on complex sustainability issues is best carried out in a place-based context (e.g., small-regional) Sustainability science needs to be sensitive to multiple scales rather than to be focused on a single scale:  Selection of a single scale can frame an investigation too narrowly  Phenomena, processes, structures, technologies, and stresses operate differently at different scales  A particular scale may be more or less important at different points in a single cause-consequence continuum  Institutions important for decision-making operate at different scales  No single scale is ideal for broad-based investigation

6

7 Consider Some Basic Concepts (contd.): Integrative research on complex sustainability issues is best carried out in a place-based context (e.g., small-regional) Sustainability science needs to be sensitive to multiple scales rather than to be focused on a single scale:  Selection of a single scale can frame an investigation too narrowly  Phenomena, processes, structures, technologies, and stresses operate differently at different scales  A particular scale may be more or less important at different points in a single cause-consequence continuum  Institutions important for decision-making operate at different scales  No single scale is ideal for broad-based investigation

8

9 Consider Some Basic Concepts (contd.): Integrative research on complex sustainability issues is best carried out in a place-based context (e.g., small-regional) Sustainability science needs to be sensitive to multiple scales rather than to be focused on a single scale:  Selection of a single scale can frame an investigation too narrowly  Phenomena, processes, structures, technologies, and stresses operate differently at different scales  A particular scale may be more or less important at different points in a single cause-consequence continuum  Institutions important for decision-making operate at different scales  No single scale is ideal for broad-based investigation

10 What Are We Learning About Scale Differences? Observations of many variables at a more localized scale show greater variance and volatility (larger scales lose valuable information) Analyses and assessments at different scales tend to be associated with different research paradigms and styles: e.g., regarding climate change responses:  Global or national scale: quantitative analysis, using net present value metrics  Small-regional or local scale: integrated assessments including significant stakeholder involvement

11

12 What Are We Learning About Scale Differences? Observations of many variables at a more localized scale show greater variance and volatility (larger scales lose valuable information) Analyses and assessments at different scales tend to be associated with different research paradigms and styles: e.g., regarding climate change responses:  Global or national scale: quantitative analysis, using net present value metrics  Small-regional or local scale: integrated assessments including significant stakeholder involvement

13 What Are We Learning About Scale Differences (contd.)? Downscaling and upscaling are likely to contribute different insights, and bottom-up investigations often provide different understandings compared with top-down investigations: see AAG/GCLP re prospects for GHG emission reduction Different scales are related to different institutional roles, and the scale of decisions is often poorly matched with the scale of processes being decided upon The choice of a scale and a set of boundaries is not politically neutral, even if the choice is not based on political considerations

14 Toward Hypotheses About How Scale Matters Ability to CaptureComplexityIntegratedAnalysis Others? InfluenceOnActions Variance Structure Agency L Scale G

15 What Are We Learning About Scale Relationships ? In many cases, cross-scale interactions are more significant than aggregate differences between scales Cross scale interactions can be considered in terms of certain basic dimensions:  Strength  Constancy  Directionality  Resolution: e.g., focused or broadcast  Context: e.g., additive or contradictory  Effect: e.g., stabilizing or destabilizing, controlling or enabling  Intent

16 What Are We Learning About Scale Relationships (contd.)? Cross-scale interactions are often associated with distinctive bridging-type institutional roles In many cases, important kinds of data about the interactions are elusive: e.g., relationships between local phenomena and national or international corporate decision-making In many cases, relationships are too complicated to be incorporated in hierarchy theory In some (many?) cases, increasing understanding calls for laying out narrative “story lines” and then exploring the connections from multiple base points (e.g., Root-Schneider’s “strategic cyclical scaling”)

17

18 In the Long Run, We Need to Be Able to Integrate Both Scale Differences and Scale Relationships in Multiscale Analysis: Cross-scale dynamics Macroscale analysis Cross-scale dynamics Mesoscale analysis Microscale analysis Cross-scale dynamics Multiscale transient relationships Cross-scale driving forces Metascale synthesis A A A A B B C B B