Heidi E.S. Mestl

Co-benefits of CO 2 -reducing policies in China - a matter of scale?

Acknowledgement of potential co-benefits - i.e. positive side-effects - of greenhouse gas mitigation policies may be of importance to promote climate policies. This paper argues that the issues of local and regional air pollution and their short to medium-term effects on human health and environment as well as greenhouse gas mitigation policies are environmental policy areas which would benefit from an integrated approach. The paper shows that contemporary Chinese policies aiming at improving energy efficiency and local air quality may lead to large reductions of CO2. Conversely, an active Chinese climate policy would likely entail reductions in emissions of air pollutants and reduced damage to human health and environment as a co-benefit. The magnitude of these short to medium-term co-benefits is, however, not clear. In the paper, we present and compare estimates of co-benefits of CO2-reducing projects and policies from studies that we have carried out in China. The studies comprise a bottom-up study in the capital of Shanxi province (Taiyuan), a semi-bottom-up study in Shanxi province as a whole, and a top-down study using a computable general equilibrium model (CGE) for China. In comparing the various options for reducing CO2, we find that the estimated co-benefits per ton carbon reduced show greater variation between options the more detailed the study design is in terms of taking into account local features of emissions and exposure.

Global burden of disease as a result of indoor air pollution in Shaanxi, Hubei and Zhejiang, China

Indoor air pollution in developing countries is a major global health problem, yet estimates of the global burden of disease vary widely and are associated with large uncertainty. The World Health Organization uses the fuel based approach to estimate 1.6 million premature deaths globally each year associated with exposure to indoor air pollution, of which 420000 are in China. The fuel based approach uses a ventilation factor to account for differences in indoor air concentrations and exposures in different parts of the world based on regional differences in stove technology. In China this approach assumes that flues eliminate the majority of indoor air pollution, with a ventilation factor of 0.25. To account for historic exposure leading to current disease patterns the ventilation factor was adjusted to 0.5 for adult health endpoints. Measurements in three Chinese provinces, Shaanxi, Hubei and Zhejiang, however, show that high PM(4) concentrations are present in kitchens and living rooms even with stoves with flues as a result of multiple stove and flue use. Comparison of Indian and Chinese indoor air concentrations suggests more appropriate ventilation factors in the range 0.76-1.0 for women and children, and 1.0 for men. Premature mortality in the three provinces using these estimates would be closer to 60600, rather than current estimates of 46000. With the addition of cardiovascular diseases these estimates would increase by 92000. Pollutant based estimates using measured indoor air concentrations and combined with dose-response estimates would imply a burden of disease of 157800 premature deaths including cardiovascular diseases, a tripling of current estimates.