Estimated (bars or solid lines) and projected (dashed lines) NG consumption (a), total CH4 emissions from NGVs (b), and changes of WTW GHG emissions of switching to NGVs (c) in China from 2000 to 2030. Gray line in a shows the reported NG consumption for the Transport, Storage, and Post sector reported in the China Statistical Yearbook (CSYB). When comparing the estimated NG consumption and NG consumption from CSYB, light-duty vehicles (without taxis) should be excluded (light blue bar in a). The error bars in a and b and the gray area in c indicate high and low estimates derived using error propagation of uncertainties of multiple input parameters. Uncertainty estimates (standard deviation, S.D.) of individual parameters are listed in Supplementary Table 1, 6, 7, 8, and 11. Source data are provided as a Source Data file.