Molecular gas depletion timescales, t_depl = M_gas/SFR, as a function of specific SFRs, sSFR = SFR/M_∗, plotted for our low-L_IR-selected SFGs (squares) and our comparison sample of SFGs and local spirals with CO measurements from the literature (see Sect. 2.2). The molecular gas depletion timescales are computed assuming a “Galactic” CO–H₂ conversion factor for all galaxies. The t_depl shows a strong dependence on sSFR. The best-fitting bisector linear relation to the z = 0 COLD GASS sample from Saintonge et al. (2011) is plotted as a dashed blue line. The z> 1 SFGs are displaced with respect to the local relation, their best-fitting bisector linear relation, log (t_depl) = (−0.83 ± 0.08)log (sSFR) + (1.43 ± 0.70), is plotted as a solid black line. The color-coding of SFGs (our sample plus z> 1 SFGs from the literature) refers to three redshift intervals: ⟨ z_1.2 ⟩ = [ 1,1.6 ] (red), ⟨ z_2.2 ⟩ = [ 2,2.5 ] (cyan), and ⟨ z_3.0 ⟩ = [ 2.7,3.2 ] (black).