Atmospheric transport models are increasingly being used to estimate CO₂ emissions from atmospheric CO₂ measurements. This study demonstrates the importance of distributing CO₂ emissions vertically in the model according to realistic profiles, since a major proportion of CO₂ is emitted through tall stacks from power plants and industrial sources. With the traditional approach of emitting all CO₂ at the surface, models may significantly overestimate the atmospheric CO₂ levels.