Due to high energy efficiency and zero emissions, some believe fuel cell vehicles (FCVs) could revolutionize the automobile industry by replacing internal combustion engine technology, and first boom in China. However, hydrogen infrastructure is one of the major barriers. Because different H-2 pathways have very different energy and emissions effects, the well-to-wheels (WTW) analyses are necessary for adequately evaluating fuel/vehicle systems. The pathways used to supply H-2 for FCVs must be carefully examined by their WTW energy use, greenhouse gases (GHGs) emissions, total criteria pollutions emissions, and urban criteria pollutions emissions. Ten hydrogen pathways in Shanghai have been simulated. The results include well-to-wheels energy use, GHGs emissions, total criteria pollutions and urban criteria pollutions. A fuel-cycle model developed at Argonne National Laboratory-called the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model-was used to evaluate well-to-wheels energy and emissions impacts of hydrogen pathways in this study. Because the initial GREET model had no coal and naphtha-based hydrogen pathways, four hydrogen pathway computer programs were added to GREET in the research. To analyze uncertain impacts, commercial software, Crystal Ball(TM) was used to conduct Monte Carlo simulations. Hence, instead of point estimates, the results of this study were probability distributions. Through the research of H-2 pathways in Shanghai, the following conclusions were achieved: (1) All the pathways have significant reductions in WTW petroleum use, except two H-2 pathways from naphtha, which achieve about 20% reductions in WTW petroleum. (2) All the pathways have significant reductions in WTW urban criteria pollutions emissions, except two H-2 pathways from coal, which result in significant increases in WTW urban SOx emissions. (3) The NG-based H-2 pathways have the best WTW energy efficiencies, and the electrolysis H-2 pathways have the worst WTW energy efficiencies. The WTW energy efficiencies of H-2 pathways from naphtha and coal are between NG-based pathways and electrolysis pathways. The pathways from naphtha have higher energy efficiencies than the pathways from coal. Only four pathways (G NG C, G NG R, G N C, and L NG C) offer WTW energy benefits and the other six pathways consume more WTW energy than baseline-conventional gasoline vehicles. WTW GHG emissions have nearly identical results to WTW energy use. (4) For WTW total criteria pollution emissions, all pathways can achieve significant reductions in WTW total VOCs and CO. The other criteria pollution emissions-NOx, PM10, and SOx, have certain reductions in NG and crude oil-based H-2 pathways but have significant increase in electrolysis and coal-based pathways. (C) 2005 Elsevier Ltd. All rights reserved.