In this research we examined the use of different models to simulate CO₂ concentrations in and around urban areas. We find that in the presence of large stack emissions in a gridded model is insufficient to represent the small dimensions of the CO₂ plumes. A plume model improves this representation up to 10–14 km from the stack. Better model results can improve the estimate of CO₂ emissions from urban areas and assist in identifying efficient emission reduction policies.