`-- Twin Cities Household Ecosystem Project Lawrence A. Baker, Cinzia Fissore, , Sarah Hobbie, Kristen Nelson,, University of Minnesota Jennifer King and Joe McFadden UC-Santa Barbara Support: NSF Biocomplexity Projects EAR-0322065 and CHN 0709581
Why study households? 1. In post-industrial cities, large fractions of C, N, and P fluxes move through households 2. Household choices are flexible, especially over time 3. Understanding household fluxes could be used to develop environmental policies 4. Households are discrete, meaningful units, and easy to study
TCHEP Goal: “Seamless, transdisciplinary model of urban biogeochemistry that links the biophysical and social components …” Inputs Carbon - natural gas, gasoline, food, jet fuel, paper, etc. N and P - human and pet food, fertilizer, etc. Outputs Carbon - CO 2 , garbage, sewage N and P - lawn runoff, sewage, garbage 2. What demographic and behavioral factors control consumption? 1. What are the “fluxes” of C, N, and P, and how does this vary among households? 3. How are environmental behavior messages processed through social networks?
Turf Inputs Compartments Outputs Transportation (household vehicles, air, mass transit) Fuel (C org ), Atmospheric N 2 Emissions (CO 2 , NO x ) Household energy (heating, cooling, appliances) Humans Food C org, N org P org Exported garbage C org , N org , P org Wastewater (C org , P org , N org PO 4 3- , NH 4 + ) Respiration (CO 2 ) Atmospheric CO 2 ; fertilizer (N org , NH 4 , NO 3 ) Soil (root zone) Trees External compost (C org , N org , P org ) Pets Export to street (runoff + leaves) (C org , P org , N org PO 4 3- , NH 4 + , NO 3 - ) Paper and plastics Paper and plastics (C org , N org ) Denitrification (N 2 , N 2 O, NO 2 ) Export to vadose zone and aquifer (NO 3 - , PO 4 3- ) Carbon, nitrogen, and phosphorus movement through households (Baker et al. 2007)
Individual choice: Theory of Planned Behavior Azjen and Fishbein (many papers) ATTITUDES TOWARD BEHAVIOR SUBJECTIVE SOCIAL NORMS PERCEIVED BEHAVIORAL CONTROL INTENT TO BEHAVE BEHAVIOR DECISION BEHAVIORAL BELIEFS (KNOWLEDGE) NORMATIVE BELIEFS CONTROL BELIEFS How this might be used: - Identify the key motivations - Identify constraints toward changing behavior - Identify method for providing information
Falcon Heights pilot study <ul><li>Pilot survey of 35 households </li></ul><ul><li>Falcon Heights, MN </li></ul><ul><li>Tools: - In-home survey (80 questions) </li></ul><ul><li>Energy bills; odometer readings </li></ul><ul><li>Landscape measurements </li></ul><ul><li>Household Flux Calculator </li></ul>
Carbon consumption varies hugely within Falcon Heights homes (Baker et al., 2007) 3X!
Full-scale TCHEP: Hybrid approach Mail survey ~ 80 multi-part questions 22 pages 30-40 minutes Household energy records (permission from respondents) GIS parcel data Ground-based vegetation survey (400 homes) UFORE model Lawn model Household Flux Calculator CO 2 emissions N and P fluxes
atm. deposition grass removal soil leaching, runoff, denitrification leaves removal fertilizers pets wood Kg N household -1 yr -1 Average landscape N fluxes INPUTS OUTPUTS ACCUMULATION
INPUTS OUTPUTS ACCUMULATION grass wood leaves leaf removal leaf decomposition heterotrophic respiration wood soil Kg C household -1 yr -1 Average landscape C fluxes
1:1 Cumulative frequency for household vehicle travel Cum. C cum. % C Cumulative % Vehicles C emissions 25 55 50 78 75 93 100 100
Broader impacts: energy and GHG emissions <ul><li>Urban sustainability efforts (ICLEI, etc.) </li></ul><ul><li>True impact of low-impact development </li></ul><ul><li>Policies to encourage conservation- targeting and tailoring </li></ul>Average carbon input to Falcon Heights homes
Broader impacts: pollution management Source reduction for urban stormwater Baker et al., Storm Water Magazine, Nov. 2007 Lawn runoff Leaf input
3 or more fertilizer applications,+ mulching Steep slope, low infiltration soil The Nowak disproportionality idea applied to lawn nutrient export High nutrient export Site characteristics Site behaviors (TCHEP survey) Baker et al., 2008, Cities and the Environment
TCHEP Status <ul><li>Hybrid survey approach successful: 3,000 completed surveys </li></ul><ul><li>Survey tool “Our Household Choices” (Nelson et al.) is published and available </li></ul><ul><li>HFC 2.0 is completed </li></ul><ul><li>First overview papers this summer </li></ul><ul><li>Developing practical and theoretical collaborations – vegetation, birds, urban stormwater, CO 2 emissions. </li></ul>