EXPLORING THE POTENTIAL FOR SPRAWL ALTERNATIVES TO REDUCE ENVIRONMENTAL DEGRADATION AND ACCOMMODATE ECONOMIC GROWTH

Transcription

1 EXPLORING THE POTENTIAL FOR SPRAWL ALTERNATIVES TO REDUCE ENVIRONMENTAL DEGRADATION AND ACCOMMODATE ECONOMIC GROWTH Post Great Recession construction boom in Charlotte NC. Photo by DAS Douglas A. Shoemaker Todd K. BenDor Melissa McHale Ross K. Meentemeyer

2 Urbanization: A Strategic Opportunity We do not know the effects of different urban forms, densities, land use mix, and alternative infrastructures. We do not know, for example, how clustered versus dispersed and monocentric versus polycentric urban structures differently affect ecological conditions. Marina Alberti, 2010 In information vacuum we routinely exchange nature s benefits for economic growth (Polasky et al 2013) Needed are studies that analyze the relationship between urban pattern and ecosystem performance 12/08/2016 Scenario analyses of urban growth patterns 4

3 Plausible* Patterns of Urban Growth Status Quo, or business as usual, or growing around existing infrastructure, disjunct and leapfrog development Entitle increased density, thereby reducing demand for land consumption De-regulate, increase per capita land consumption *US 12/08/2016 Scenario analyses of urban growth patterns 7

4 Assessing Landscape Performance Realistic Projections Change over time Quantification t 0, t 1, t 0 -t 1 Greenfield Conversion Event FUTURES (Meentemeyer et al. 2013) Biophysical Response Effect Societally relevant metrics ($), anticipates trade-offs 12/08/2016 Scenario analyses of urban growth patterns 11

5 Caveats: Results drawn from a simulated study system Correspondence with real world conditions untested Limit analyses to comparisons of alternative futures Many ecosystem services are not monitored Practice should incorporate a wide range of services Greenfield Conversion Event Biophysical Response Impacts Quantification t 0, t 1, t 0 -t 1 12/08/2016 Scenario analyses of urban growth patterns 12

6 Caveats: Results drawn from a simulated study system Correspondence with real world conditions untested Limit analyses to comparisons of alternative futures Many ecosystem services are not monitored Practice should incorporate a wide range of services Greenfield Conversion Event Biophysical Response Impacts Quantification t 0, t 1, t 0 -t 1 12/08/2016 Scenario analyses of urban growth patterns 13

7 Study System: Rapidly Growing Charlotte NC NSF ULTRA-Ex Site Published Studies Meentemeyer et al Bendor et al Dorning et al. 2015a Dorning et al. 2015b Smith et al. In review 2006 Population: approx. 1.1 million (+235% since 1976) Area: 346,000 ha Long urban gradient ideal for sampling 46% Canopy Cover*, Tops Med-Large US Cities *American Forests 2010 Charlotte 12/08/2016 Scenario analyses of urban growth patterns 14

8 Which Fragments More? Start 2006 Water, 0.50% Fragmentation Analyses Agriculture Passive 16.62% Development 22.68% Agriculture Intensive, 6.81% Forest, 53.22% Extant Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 15

9 Which Fragments More? Status Quo 2030 Agriculture Intensive, 4.70% Agriculture Passive, 10.27% Water, 0.50% Fragmentation Analyses Forest, 30.67% Development New, 31.32% Development Extant, 22.68% Extant Development Projected Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 16

10 Which Fragments More? 2030 Agriculture Intensive, 4.80% Agriculture Passive, 10.98% Forest, 30.96% Water, 0.50% Fragmentation Analyses Development New, 30.11% Development Extant, 22.68% Extant Development Projected Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 17

11 Which Fragments More? 2030 Agriculture Intensive, 4.90% Agriculture Passive, 10.18% Water, 0.50% Fragmentation Analyses Forest, 29.49% Development New, 32.30% Development Extant, 22.68% Extant Development Projected Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 18

12 Which Fragments More? + Land Consumption 2030 Agriculture Intensive 4.30% Agriculture Passive 9.20% Water, 0.50% Fragmentation Analyses Forest 26.55% Development New 36.83% Development Extant, 22.68% Extant Development Projected Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 19

13 Which Fragments More? + Density 2030 Agriculture Intensive, 5.05% Agriculture Passive, 11.39% Water, 0.50% Fragmentation Analyses Development New 25.59% Forest, 34.79% Development Extant, 22.68% Extant Development Projected Development Forest/Agricultural Land Covers Subwatershed Delineation 12/08/2016 Scenario analyses of urban growth patterns 20

14 How Does Habitat Change? Start + Land Consumption Urban Tolerance Vertebrates Intolerant Partial Tolerance Moderate Tolerance High Tolerance Water Status-quo Model source: SE GAP + Density 12/08/2016 Scenario analyses of urban growth patterns 22

15 How Does Habitat Change? Start Significant Change from Status Quo Increase + Land Consumption Decrease Urban Tolerance Vertebrates Intolerant Partial Tolerance Moderate Tolerance High Tolerance Water Status-quo * The mean difference is significant at the 0.05 level + Density 12/08/2016 Scenario analyses of urban growth patterns 23

16 How Does Habitat Change? Start Urban Tolerance + Land Consumption Intolerant Partial Moderate High Urban Tolerance Vertebrates Intolerant Partial Tolerance Moderate Tolerance High Tolerance Water Status Quo Status-quo +LC +DEN + Density 12/08/2016 Scenario analyses of urban growth patterns 24

17 Which Exports Least N NPS Pollution? Start + Land Consumption N Exports kg/ha High : Low : Water Status-quo Model source: InVEST 3.1x + Density 12/08/2016 Scenario analyses of urban growth patterns 27

18 Which Exports Least N NPS Pollution? Start Significant Change from Status Quo Decrease Increase + Land Consumption N Exports kg/ha High : Low : Water Status-quo * The mean difference is significant at the 0.05 level + Density 12/08/2016 Scenario analyses of urban growth patterns 28

19 What Are The Costs Over Time? Start $0 + Land Consumption NC Nitrogen offset Fee = $43.85/kg $8.89 $8.76 $9.21 $9.33 $8.46 Present value of the cost of N offsets= N Exports kg/ha High : Low : Water $ millions Status-quo Status Quo +LC +DEN N kg/yr * $43.85/kg * 24 yrs, discounted 4.0%/yr + Density 12/08/2016 Scenario analyses of urban growth patterns 29

20 Which Exports Least P NPS Pollution? Start + Land Consumption P Exports Kg/ha High : 5.71 Low : Water Status-quo Model source: InVEST 3.1x + Density 12/08/2016 Scenario analyses of urban growth patterns 32

21 Which Exports Least P NPS Pollution? Start Significant Change from Status Quo Decrease Increase + Land Consumption P Exports Kg/ha High : 5.71 Low : Water Status-quo * The mean difference is significant at the 0.05 level + Density 12/08/2016 Scenario analyses of urban growth patterns 33

22 What Are The Costs Over Time? Start $0 + Land Consumption NC Phosphorus offset Fee = $524.32/kg $18.5 $18.1 $19.3 $19.4 $17.5 Present value of the cost of P offsets= P Exports Kg/ha High : 5.71 Low : Water $ millions Status Quo Status-quo +LC +DEN N kg/yr * $524.32/kg * 24 yrs, discounted 4.0%/yr + Density 12/08/2016 Scenario analyses of urban growth patterns 34

23 Which Sequesters the Most Carbon? Start C Storage (Mg per ha) High : Land Consumption Low : Water 0 C Sequestration Mg/Pixel High : Unchanged : 0 Low : Status-quo + Density 12/08/2016 Scenario analyses of urban growth patterns 37

24 Which Sequesters the Most Carbon? Start C Storage (Mg per ha) High : Low : Water 0 Significant Change from Status Quo Increase Decrease + Land Consumption C Sequestration Mg/Pixel High : Unchanged : 0 Low : Status-quo * The mean difference is significant at the 0.05 level + Density 12/08/2016 Scenario analyses of urban growth patterns 38

25 What Are The Costs Over Time? Start C Storage (t per ha) $0 High : Low : Water 0 + Land Consumption Societal Cost of Carbon = $60/Mg C Sequestration Avoided Cost / ha $USD, High : $34,122 Low : -$35,671 $2.85 $2.65 $3.67 $3.39 $2.35 Pres $ millions Status-quo Status Quo +LC +DEN Present value of C sequestration = C Mg/yr * $60.00/Mg * 24 yrs, discounted 4.0%/yr + Density 12/08/2016 Scenario analyses of urban growth patterns 39 cost, carbo Mg C 24 yr 4.0%

26 Research Design Start 2006 Estimate of net returns to landowners from urban development, forests, cropland and pasture, 2015 dollars ($USD/year) Source: Lubowski et al 2008, cited in Polasky et al Character: Spatially implicit Landowner Revenues $/ha/yr $0 (Water) $65.57 $88.83 $ USD$ 2015 $12, Method: Relate land covers to empirically derived net return estimates Caveats: Revenues for + Density and + Land Consumption adjusted to perpixel population (scaling factor 1.4, 0.6 respectively) 12/08/2016 Scenario analyses of urban growth patterns 40

27 Which Generates the Most Returns to Landowners Over Time? Start + Land Consumption Landowner Revenues $/ha/yr $0 (Water) $65.57 $88.83 $ $12, USD$ 2015 Status-quo + Density Source: Lubowski et al 2008, cited in Polasky et al /08/2016 Scenario analyses of urban growth patterns 41

28 Which Generates the Most Returns to Landowners Over Time? $ millions Start + Land Consumption $646.9 $636.4 $655.3 $495.1 $760.6 Present value of returns of land ($USD 2015, discount rate 4%) Landowner Revenues $/ha/yr $0 (Water) $65.57 $88.83 $ USD$ 2015 $12, Status Quo +LC +DEN Status-quo + Density 12/08/2016 Scenario analyses of urban growth patterns 43

29 Which Is Least Costly Environmental Services (N, P, C)? Costs, Environmental Services Trade-offs Role of Configuration $0 $ millions Offset N Exports Offset P Exports Avoided Cost Carbon Combined Suite Environmental Services $30.2 $29.5 $32.2 $ Status Quo +LC +DEN 12/08/2016 Scenario analyses of urban growth patterns 44

30 How Do Environmental Costs Compare with Revenues? Costs, Environmental Services Trade-offs Role of Configuration $760.6 Combined N, P, C Costs $646.9 $636.4 $655.3 $495.1 Estimated Returns to Landowners $30.2 $29.5 $32.2 $ $ millions Status Quo +LC +DEN 12/08/2016 Scenario analyses of urban growth patterns 45

31 What are Trade-offs with Biodiversity? Costs, Environmental Services Trade-offs Role of Configuration $732.3 Landscape Net For a Suite of Values $616.8 $606.9 $623.2 $ ,000 45,000 30,000 15,000 INTOLERANT VERT. HABITAT (ha) Status Quo +LC +DEN 12/08/2016 Scenario analyses of urban growth patterns 46

32 Are There Traps to Avoid? Costs, Environmental Services Trade-offs Role of Configuration Urban Tolerance Nitrogen Exports Phosphorus Exports Carbons Sequestration Trap 1. Aspatial Thinking>>Place Matters Trap 2. One size fits all thinking Trap 3. Failure to embrace density Change from SQ* -1 1 * The mean difference is significant at the 0.05 level 12/08/2016 Scenario analyses of urban growth patterns 47