1. The Behavioral Wedge Household Actions Can Provide a Behavioral Wedge to Rapidly Reduce U.S. Carbon Emissions Proceedings of the National Academy of Sciences October 2009 Thomas Dietz Gerald T. Gardner Jonathan Gilligan Paul C. Stern Michael P. Vandenbergh

2. 2  Growing recognition of the need for prompt, viable emissions reduction options  Household direct energy use ~ 626 MtC or ~38% of US 2005 CO 2 emissions  8% of global CO 2 emissions  Larger than total from any country but China  Indirect measures taken to date The Opportunity

3. 3  Household Actions: 17 types of household actions that can reduce energy consumption with available technology, low cost, and without appreciable lifestyle changes  Reasonably Achievable Emissions Reduction (RAER) of 20% in 10 years  123 MtC or 7.4% of total current US emissions  Comparable to  Total emissions of France; or  Total emissions of petroleum refining, iron & steel, and aluminum industries Results

4. 4  Single interventions often ineffective  Effective interventions  Strong Social Marketing: mass media appeals plus participatory, community-based approaches  Multiple Targets: individuals, communities, businesses  Synergistic Effects: can arise from combinations of mass media appeals, information, financial incentives, informal social incentives, reduction of transaction costs Effective Interventions

5. 5  PER: potential emissions reduction if 100% adoption (accounting for existing penetration)  Plasticity: the proportion of non-adoptors that could be induced to take action  Reasonably Achievable Emissions Reduction:  RAER = PER x Plasticity  Corrected for double-counting  Not corrected for potential “take-back”  RAER Estimate  10-year RAER: 20% of household emissions (7.4% of US total)  5-year RAER: 13% of household emissions (5.2% of US total) RAER

6. 6  17 types and 33 specific actions  5 categories  W Actions: home weatherization, etc.  E Actions: more efficient vehicles and non- heating and cooling equipment  M Actions: equipment maintenance  A Actions: equipment adjustments  D Actions: daily use behavior Actions

7. 7  Plasticity estimates are based on the most effective documented interventions that do not involve regulation of technology or behavior  Not relying on generic indicators of plasticity (e.g. price elasticity of demand)  Economic and non-economic stimuli considered  Responsiveness to price can vary by a factor of 10 based on non-financial aspects of policy Distinctions

8. Behavior ChangeCategory Potential Emissions Reduction (MTC) Behavioral Plasticity RAER (MTC) RAER (%I/H) WeatherizationW25.290%21.23.39% HVAC EquipmentW12.280%10.71.72% Low-flow showerheadsE1.480%1.10.18% Efficient water heaterE6.780%5.40.86% AppliancesE14.780%11.71.87% LRR tiresE7.480%6.51.05% Fuel-efficient vehicleE56.350%31.45.02% Change HVAC air filtersM8.730%3.70.59% Tune up ACM3.030%1.40.22% Routine Auto MaintenanceM8.630%4.10.66% Laundry temperatureA0.535%0.20.04% Water heater temperatureA2.935%1.00.17% Standby electricityD9.235%3.20.52% Thermostat setbacksD10.135%4.50.71% Line dryingD6.035%2.20.35% Driving behaviorD24.125%7.71.23% Carpooling & Trip-chainingD36.115%6.41.02% Totals 233 12320% Table 1. Achievable carbon emissions from household actions

9. PER and RAER

10. 10  Adequate to demonstrate RAER  Critical needs  Current penetration of energy efficient equipment  Plasticity arising from separate and combined interventions  Other needs  Program evaluation  Costs  Institutional requirements State of Research

11. 11  Pacala & Socolow (2004)  Stabilization wedge = 1 GtC in 50 years; 25 GtC over 50 year period  7 wedges needed to stabilize emissions  US = ~ 20% or 200 MtC/yr per wedge in 50 years; 1.4 GtC/yr in 50 years  7 US wedges in 10 years = 210 MtC/yr  RAER-10 = 123 MtC or ~3 wedges (44% of US year 10 contribution) Stabilization Wedges

12. 12  Global change  Australia and Canada  EU and Japan  Developing Countries  New technologies (e.g., LED)  Lifestyle changes  Policy changes  International leadership Additional Opportunities