1. Bay Area Consumption-Based Greenhouse Gas Emissions Inventory
California Resource Recovery Association Sustainable Material Management Conference
Session 152: Sustainable Material Management
Sacramento, CA
August 8, 2016
David Burch Principal Planner, Bay Area AQMD
375 Beale Street, Suite 600
San Francisco, CA 94105

2. Overview of Presentation
Describe Bay Area AQMD efforts to reduce emissions of air pollutants and greenhouse gases (GHGs)
Regional Climate Protection Strategy
Importance of reducing methane & other short-lived climate pollutants
Measures to reduce emissions from waste & agriculture
Key findings from Bay Area consumption-based GHG emissions

3. Bay Area Air Quality Management District
Large, complex region:
9 counties / 101 cities
7 million + people
2.6 million households
5 million + vehicles
Our Mission:
Attain air quality standards
Protect public health
Protect the climate
Governing Board made up of local elected officials

4. 2016 Bay Area Clean Air Plan
Multi-pollutant plan to reduce emissions of: - criteria air pollutants - greenhouse gases (GHGs)
Define a Regional Climate Protection Strategy
Help implement statewide AB 32 Scoping Plan
Assist climate planning in local cities

5. Economic Sector Analysis
Identify Air District actions that complement State programs to reduce emissions from all economic sectors
Transportation
Energy
Agriculture
Water
Waste
Buildings
Stationary Sources
Natural & Working Lands
Short-lived Climate Pollutants

6. Bay Area GHG Emissions 2015 GHG Emissions by Sector (Production-Based)
100-year global warming potentials (GWPs)
Total = ~ 90 MMT CO2eq

7. Opportunities & Tools Opportunities: Tools & Resources:
Promote efficiency / reduce demand
Decarbonize electricity
Promote electrification
Reduce short-lived climate pollutants (SLCPs) - methane - black carbon - high-GWP gases
Tools & Resources:
Research & measurement
Regulations
Permits & enforcement
Grants
Partnerships & collaboration
Public education

8. Importance of Reducing SLCPs
SLCPs have been overlooked until recently
Since SLCPs are “front-loaded”, reducing them helps to ward off global warming in short-term
Can help to prevent negative feedback loops that exacerbate global warming
Buy time to develop & implement CO2 reduction strategies

9. Methane Emissions
Methane is 2nd largest GHG in Bay Area & California GHG inventory
High global warming potential: - GWP of 34, using 100-year timeframe - GWP of 86, using 20-year timeframe
Largest sources of methane in Bay Area: - Waste sector (landfills): ~ 50% - Agriculture (animal waste) ~ 27% - Natural gas distribution ~ 14%
Methane emissions may be underestimated

10. Proposed Measures to Reduce Emissions from Waste Sector
Strengthen existing rule (Reg 8-34) to reduce emissions of GHGs, reactive organics, and air toxics
Develop rule to reduce emissions from composting and anaerobic digestion
Encourage local ordinances and programs to reduce green waste going to landfills
Promote recycling & waste reduction: - e.g. construction & demolition materials

11. Proposed Measures to Reduce Emissions from Agriculture
Encourage promote measures to reduce carbon in farming, such as carbon sequestration & biogas recovery
Promote use of dairy digesters
Reduce emissions from enteric fermentation via grazing management & dietary strategies
Apply best management practices at Bay Area dairies and animal feed lots

12. GHG Emissions Inventory
Conventional production-based emissions inventory focuses on supply: - Estimate emissions from goods & services produced in a given area
Consumption-based emissions inventory (CBEI) focuses on demand: - Estimate emissions embedded in goods & services consumed in a given area
CBEI attributes all emissions to the final user/consumer - regardless of location where emissions actually occurred
Business sector is treated as an intermediary, not a final user
Emissions from government sector are not included 3

13. Why Develop a CBEI?
Production-based inventory does not tell the whole story
Modern economy is highly integrated, national & global in scale
Major portion of goods & services are imported to region
Quantify and account for (indirect) emissions that are generated beyond our boundaries
Provide a more complete analysis of our true GHG footprint
Collaborated with Dr. Chris UC Berkeley Cool Climate Network. (See Panel 150 at 9:00 am on Tuesday.)

14. Potential Uses of CBEI
Inform Bay Area Regional Climate Protection Strategy - identify potential GHG reduction policies
Assist climate planning in local cities - consider local variation in emissions footprint
Help educate Bay Area residents about most effective ways to reduce their GHG footprint

15. Basic Approach
Kyoto 6 greenhouse gases - CO2, methane, N20, HFCs, PFCs, SF6
Estimate GHG footprint of average household: - Transportation, Housing, Food, Goods, Services
Fine-grain scale: each of 4,700 Census block groups in Bay Area
Step 1: Develop a consumption profile for each Census block group
Step 2: Multiply consumption inputs x life-cycle emissions factors
Step 3: Add emissions for each product or service to calculate total GHG footprint

16. Life Cycle Emissions for Automobile
Upstream
In-Use
Downstream
Shipping to Dealer
Fuel Consumption
Fuel economy
Fuel type
Driving conditions
Landfill
Individual Parts
Production, including upstream emissions for each part
Vehicle Assembly
Vehicle Maintenance
Recycling / re-use (credit)
Upstream emissions from refining gasoline

17. Major Expenditure Categories
Food:
Grains & cereals
Fruits & vegetables
Dairy
Meat
Other
Goods:
Clothing
Furniture & appliances
Personal care products
Books, newspapers, CDs
Services:
Health care
Education
Financial services
Communication
Entertainment
Transportation:
Motor vehicle production
Vehicle maintenance
Vehicle fuel consumption (driving)
Public transportation
Air travel
Housing:
Construction
Maintenance
Residential energy use
Water
Waste
41.3
7.4
17.5
27.6

18. US Average Household GHG Footprint
Transportation
Average 49.8 metric tons CO2e per household
Blue = direct emissions Green = indirect emissions
Blue = direct emissions
Green = indirect emissions
Housing
Food
Goods
Services
31%
26%
18%
12%
12%

19. SF Bay Area Average Household GHG Footprint
Average 44.3 metric tons CO2e per household
Blue = direct emissions Green = indirect emissions
Transportation
Housing
Food
Goods
Services
33%
14%
19%
17%
17%

20. Key Factors Cool Climate Network model includes 30+ factors
But 6 factors account for 92% of variation in GHG footprint
household size (# people)
household income
size of home (square footage of dwelling unit)
population density of neighborhood
carbon intensity of electricity
vehicle ownership rate 20

21. GHG Emissions and Household Income
Household income has strong influence on both magnitude and composition of emissions - transportation - goods - services
Lower income households spend larger portion of income on basic food & housing
As income increases, people spend more on discretionary goods & services 21

22. Local Variation in GHG Footprint
Large variation in size and composition of GHG footprint
GHG footprint is generally lower in urban core areas - smaller homes, lower vehicle ownership rate, better transit
Variation between block groups: ratio of 7 to 1
Variation within (large cities): ratio of 4 or 5 to 1
Variation between cities: ratio of 3 to 1
Less variation between counties: - County average footprint ranges from 39 to 49 metric tons per household
Can we tailor emissions reduction policies to reflect this local variation? 22

23. CBEI Products Total Emissions
Inventory tables & graphs at regional, county, and city scale
Maps showing GHG footprint at fine-grained local scale 23

24. Block Group Detail
Block Group Detail

25. Example: GHG Emissions – Food Sector
Food is GHG-intensive: accounts for ~ 10% of total expenditures, but 19% of Bay Area GHG emissions.
Red meat & dairy are the most GHG-intensive food groups - reduce food waste - promote low-GHG diet: less processed food, less meat & dairy
Source: Food-Miles & Relative Climate Impacts of Food Choices in the US. Environmental Science & Technology: Vol 42, No. 10, 2008

26. Policy Implications
Transportation - Need to decarbonize transportation sector - Direct growth to areas served by transit, shopping, services Housing - Promote electric space & water heating in homes & buildings - Retrofit existing homes to increase energy efficiency - Encourage appropriate (smaller) home size
Food - Reduce food waste - Low-carbon diet: Eat lower on food chain / less processed food
Goods & Services - buy locally-produced goods & services - consume less goods, more services 26

27. For Additional Information
Final Report on consumption-based GHG inventory
Tables & graphs showing data for each city and county
Interactive on-line map showing variation in size & composition of GHG footprint by Census block group
Cool Climate Calculator (individual household)
Dave Burch: / 21 27