Rufus D. Edwards, Kirk R. Smith, Junfeng Zhang, Yuqing Ma   |   2004
Type: Research Report
Topic: Environment/Climate, Health
Country: China
In recent decades China has pursued a number of national energy policies as integral components of its 5-year development plans including the unprecedented dissemination of several generations of fuel saving stoves in the majority of its rural populations. These programs, although designed for conservation of fuel wood resources and using deceptively simple technologies, have much wider impacts on both a national and a global level through their impacts on health and emission of pollutants that have warming consequences for the atmosphere. In the current manuscript we examine these implications using emissions data collected as part of a comprehensive evaluation of 28 typical stove/fuel technologies in common use. We illustrate that relative benefits of biomass and fossil fuels, and subsequently policies regarding promotion of different fuel types, are dependent on which products of incomplete combustion are considered. If one only considers gases included within the Kyoto protocol, the burning of renewably harvested biomass appears to have an advantage over kerosene or LPG as a large component of PIC emissions from inefficient biomass stoves are not included in the calculation. If, however, one considers a more comprehensive list of compounds that have direct or indirect effects on global warming, at best the burning of fuel wood when 100% renewably harvested has a similar GWC to these better quality fuels, and, under conditions experienced in many rural areas of the world, often considerably worse. Comprehensive evaluation would require all major radiative forcing agents to be considered, even though that presents considerable difficulties considering reported uncertainties of some global warming potentials. The stove types in this study demonstrated a wide range of emission factors. This offers an effective mechanism for achieving short-term reduction in emissions of health damaging pollutants, and also accomplishes the longer-term goal of reducing of greenhouse gas emissions. Not all the improved stoves resulted in benefits on all levels, however, and it is possible, therefore, to implement policies with the best intentions for alleviating the burden of collecting fuel, which may actually, result in increased exposure of the population to health damaging pollutants and increased global warming contributions. In addition, the difference between global warming commitments for renewable and non-renewable harvesting of biomass fuels was of such magnitude, especially compared to differences between stove types, that more detailed accounting of the renewable nature of the harvesting of biomass fuels is essential and has profound implications for global accounting of carbon emissions and credit through the clean development mechanism. Clearly, however, evaluation of biomass burning in residential stoves requires a more holistic, or full fuel cycle approach that considers both the production of the fuel wood, the burning of the fuel, sequestration of gases during the next growing season and the environmental degradation and shift in fuels that may occur due to mining of the resource.