Spatial distributions of fossil fuel emissions (tC/grid) for 14 cities and metropolitan regions in the year listed in Table 1 based on the ODIAC inventory (1 km resolution). Manhattan is located in the upper left part in New York City showed in region (i). Grid points with high emissions (shown red) clearly represent some large point sources. Three scale bars were chosen in this distribution. Scale bar (1) corresponds to region (a–e), scale bar (2) to region (f) to (l) and scale bar (3) to Washington D.C.