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Abstract: This paper uses nonparametric efficiency analysis technique to estimate the energy efficiency, potential emission reductions and marginal abatement costs of energy-related CO2 emissions in China. We employ a non-radial slacks-based data envelopment analysis (DEA) model for estimating the potential reductions and efficiency of CO2 emissions for China. The dual model of the slacks-based DEA model is then used to estimate the marginal abatement costs of CO2 emissions. An empirical study based on China’s panel data (2001–2010) is carried out and some policy implications are also discussed. [Copyright &y& Elsevier]

Abstract: Following model evaluation in part I, this part II paper focuses on the process analysis and chemical regime analysis for the formation of ozone (O3) and particulate matter with aerodynamic diameter less than or equal to 10 μm (PM10) in China. The process analysis results show that horizontal transport is the main contributor to the accumulation of O3 in Jan., Apr., and Oct., and gas-phase chemistry and vertical transport contribute to the production and accumulation of O3 in Jul. Removal pathways of O3 include vertical and horizontal transport, gas-phase chemistry, and cloud processes, depending on locations and seasons. PM10 is mainly produced by primary emissions and aerosol processes and removed by horizontal transport. Cloud processes could either decrease or increase PM10 concentrations, depending on locations and seasons. Among all indicators examined, the ratio of provides the most robust indicator for O3 chemistry, indicating a VOC-limited O3 chemistry over most of the eastern China in Jan., NOx-limited in Jul., and either VOC- or NOx-limited in Apr. and Oct. O3 chemistry is NOx-limited in most central and western China and VOC-limited in major cities throughout the year. The adjusted gas ratio, AdjGR, indicates that PM formation in the eastern China is most sensitive to the emissions of SO2 and may be more sensitive to emission reductions in NOx than in NH3. These results are fairly consistent with the responses of O3 and PM2.5 to the reductions of their precursor emissions predicted from sensitivity simulations. A 50% reduction of NOx or AVOC emissions leads to a reduction of O3 over the eastern China. Unlike the reduction of emissions of SO2, NOx, and NH3 that leads to a decrease in PM10, a 50% reduction of AVOC emissions increases PM10 levels. Such results indicate the complexity of O3 and PM chemistry and a need for an integrated, region-specific emission control strategy with seasonal variations to effectively control both O3 and PM2.5 pollution in China. [Copyright &y& Elsevier]

Abstract: This paper presents life-cycle-analysis (LCA) energy consumption (EC) and greenhouse gas (GHG) emissions of China’s current six biofuel pathways, which are: corn-derived ethanol (CE); cassava-derived ethanol (KE); sweet sorghum-derived ethanol (SE); soybean-derived bio-diesel (SB); jatropha fruit-derived bio-diesel (JB); and used cooking oil (UCO)-derived bio-diesel (UB). The tool utilized here is the WTW (Well-to-Wheels) module of Tsinghua-CA3EM model covering the entire lifecycle including: raw materials cultivation (or feedstock collection); fuel production; transportation and distribution; and application in automobile engines, compared with Conventional Petroleum-based gasoline and diesel Pathways (CPP). The results indicate: (1) the fossil energy inputs are about 1.0–1.5 times the energy contained in the fuel for the CE, SE and SB pathways, but 0.5–0.9 times for the KE, UB and JB pathways; (2) compared with CPP, the JB, KE and UB pathways can reduce both fossil fuel consumption and GHG emissions; the CE and SB pathways can only reduce fossil fuel consumption, but increase GHG emission; the SE pathway increases not only fossil fuel consumption but also GHG emission; and (3) the main factors inducing high EC and GHG emission levels include: high EC levels during the fuel production stage and high fertilizer application rates during the planting of raw feedstocks. Conclusions are that of the aforementioned biofuel pathways in China: (1) only the JB, KE and UB pathways have energy-saving merits as indicated by the LCA energy inputs and outputs; (2) compared with CPP, all but the SE pathway reduces fossil fuel consumption. However, the SB and CE pathway increase GHG emission; (3) all six displace petroleum by utilizing more coal; and (4) feedstock productivity levels must be increased, and there must be a reduction in fertilizer utilization and EC consumption during the cultivation and transportation stages in order to achieve the goals of energy balance and GHG emission reduction. [Copyright &y& Elsevier]