Comparison of observed (green and blue background) and predicted cumulative CO emission: 1–0, 2–1, and 3–2. The predicted values are for A_V = 30 mag (end of the cloud). Panel on the left: predicted values as a function of G_X for models with turbulence of 10 km s⁻¹ and solar metallicity. Panel on the right: predicted values as a function of turbulence for models with G_X = 10 and solar metallicity.