1 Jonathan Sinton, Kirk Smith, and Rufus Edwards University of California, Berkeley and Irvine Presented at: Mitigation of air pollution and climate change in China October 17-19, 2004 Oslo, Norway Implications for GHG Emissions of Evolving Patterns of Stove and Fuel Use in China's Rural Households

2 Topics Trends in fuel use in China’s rural households Trends in stove design and usage patterns Methods of estimating global warming potential from stove use Daily and seasonal variations Next steps

3 Trends in fuel use

4 Data sources limited National Bureau of Statistics Surveys by Ministry of Agriculture Disparate studies undertaken by various research groups No detailed regular national surveys of energy use in households, rural or urban.

5 Shares of energy use by type in rural households, 2002 Source: NBS, 2004.

6 …but different sources give different data. MOA (1998 data) NBS (1999 data) Rural households, shares of energy use

7 Data generated from review of China's improved stoves programs Multiple research objectives: –Stove Programs –Stove Function –Indoor Air Quality –Health Surveys conducted , analysis ongoing. Participating organizations: –The Institute for Global Health and the School of Public Health, University of California, San Francisco and Berkeley –China Centers for Disease Control –Renmin University –Tsinghua University Funding: –Household Energy and Health Program of the Shell Foundation –Fogarty International Center, Bethesda MD

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9 Village Biomass Storage

10 Mixed Fuels

11 Main cooking fuels varied significantly by region in survey results.

12 Space heating fuels varied substantially as well, and revealed a surprising reliance on charcoal.

13 Stove design and usage

14 Dissemination of improved stoves in rural China and number of rural households Source: Edwards & Smith, 2002

15 Improved Biomass Stoves in China More than 180 million introduced since 1983

16 Bellows in traditional biomass stove, Zhejiang

17 Unvented biomass stove, concrete construction, Hubei

18 Open fires for boiling water, used in addition to other stoves, Hubei

19 “Semi-improved” biomass stove, Shaanxi

20 Improved biomass stove, Shaanxi

21 Traditional and improved coal heating stoves, Shaanxi

22 Traditional and improved coal cook stoves, Shaanxi

23 Portable coal briquette stove, Shaanxi

24 Store with coal stoves, Shaanxi

25 Multi-function coal stove, unvented

26 Coal heating and cooking stove with chimney installed for winter, Shaanxi

27 Cooking and heating stove without chimney, Shaanxi Also used for kang (heated platform bed)

28 Continuous-feeding household biomass gasifier stove - $90

29 Rates of ownership of different type of stoves show distinct regional patterns.

30 Efficiencies of stoves vary across region and across type—implying variations also in emissions characteristics.

31 Estimating global warming potential of stove emissions

32 2-5% of CH4 emissions 6-15% of CO emissions 8-25% of hydrocarbon emissions 4-8% of all human-generated global warming from gases Significant contributor of black carbon (BC) emissions Why? Biomass fuel emissions are globally significant.

33 Global Carbon Cycle What goes on here?

34 Work to date and ongoing Measure 55 climate-warming and health-damaging pollutant emissions from 28 fuel/stove combinations popular in rural and urban China simultaneously with efficiency and other performance parameters. Funded by USEPA, began in Independent review of China’s National Improved Stoves Program (NISP), which introduced over 180 million improved stoves in rural areas by the late 1990s. Funded by Shell Foundation, began in Results for China of the global Comparative Risk Assessment on health impacts of indoor and outdoor air pollution. Study on fuel/stove combinations in India.

35 Triple Carbon-Balance Analysis of a combustion device Energy Health Global Warming Co-benefits Possible with any two

36 Carbon-balance Analysis: Combustion Follow the fuel carbon PIC = PIC = products of incomplete combustion TNMHC = total non-methane hydrocarbons TSP = total suspended particulates

37 Triple Carbon Balance: Energy (Smith, 1994)

38 Triple Carbon Balance: Health (concentrations of pollutants)

39 Triple Carbon Balance: Global Warming Potential

40 Calculation of global warming commitments 20-year GWP Smith et al 2000 Molar basis (per carbon atom) CO CH CO 4.5 TNMHC year GWP IPCC 1990 per kg relative to CO 2 NO x 150 CH Black carbon?

41 GWC = Global Warming Commitment Global Warming Commitment Per Meal

42 Kyoto GWC of different household fuels in China: CO 2 +CH 4 GWC g C as CO 2 per MJ delivered Non-renewable

43 Total GWC of different household fuels in China: CO 2 +CH 4 +CO+TNMHC+NO x GWC g C as CO 2 per MJ delivered Non-renewable

44 Emissions of CO and PM Error bars represent different stove types

45 Seasonal patterns

46 Seasonal variabilithy in fuels & stove use is significant Highly diverse fuel usage patterns in these regions in China. In approx 250 homes in the IAP database: –In Winter, 28 different fuel combinations used in the kitchens –In Summer, 34 different fuel combinations in the kitchens. –Multiple fuels used in the majority of the houses in the database during both the winter and the summer. –In houses that were measured in both seasons in Shaanxi there was a shift in the fuel usage patterns between seasons.

47 Summer Note: biomass and agricultural residues feature strongly; Kitchens higher than living rooms

48 Winter Note: Overall range of levels higher than in summer; Livingrooms higher than kitchens

49 Improved stoves and indoor air levels In the summer, improved stoves were associated with significantly lower PM4 indoor concentrations for biomass fuel combinations which would be burned in the same stove (wood logs wood twigs and crop residues).

50 Three examples of different stove usage patterns (CO levels in the kitchens) a) Elevated levels during cooking events

51 b) Elevated levels during the night

52 c) continually elevated levels during the day and night

53 Next steps

54 Work in progress: Estimation of seasonal variation in GWP Calculation and analysis ongoing. Expect to find variation in GWP among regions, times of day, and seasons. How much would results have to vary to be considered significant? For example, could we ignore seasonal fluctuations of 25%? Would models have to be revised to account for larger fluctuations?

55 Potential policy implications: Co- benefit calculations Current co-benefit calculations do not incorporate seasonal changes in fuel use. Emissions from both living areas and kitchens must be considered. Health and GWP impacts of interventions may differ seasonally in independent ways. If shift in cooking fuels also results in increased space heating using more-polluting solid fuels, then desired reductions in GWP may not be realized. Plumes of pollution downwind of rural areas may vary seasonally in both concentration and composition.

56 Implications for research: Improve characterization of rural fuels & stoves Institute regular household energy surveys –Nationally representative –Stocks of stoves in addition to other energy- using devices (NBS surveys already cover electrical appliances) –Ideally coordinate between MOA and NBS Requires high-level commitment, coordination

57 More implications for research: Gathering of data on seasonal variations Survey work should include monthly observations for at least one full year Field monitoring of stoves under normal operating conditions is key Surveys will need: –Low-cost, monitoring and analytic methods –Locally based survey teams –Strong coordinator

58 Thank you