Urban areas contain multiple sources and sinks of carbon dioxide, yet spatial and temporal information explaining its variability, diurnal patterns, and effects from human activity are limited. The city of Atlanta, due to conflicting air masses, geographic location, and population growth, is as an excellent location to study carbon dioxide concentrations across its urban landscape. Mobile measurements of ambient CO2 concentrations were obtained at 1.5m above ground level along a transect in winter 2010 within the perimeter of Atlanta. Analyses of winter 2010 CO2 variability at GSU’s stationary CO2 monitor was also explored. The results showed that CO2 concentrations in Atlanta are highly variable. The GSU CO2 station showed that weekday CO2 concentrations to be significantly higher than weekends suggesting that anthropogenic emissions may be the cause.