Comparison of the α_CO conversion factor to the bulk of ISM turbulence (left: rms 3D velocity dispersion divided by , mass-weighted average of the measurements for gas identified as molecular) and to the velocity gradient along lines of sight of molecular emission (right: mass-weighted average of the dV/dr gradient along lines-of-sight crossing gas identified as molecular). Average values and rms scatter are displayed for each galaxy type and for the giant clumps of high-z galaxies.