This paper examines the value of detailed logistics information for calculating carbon footprints. The carbon footprint of transporting a product from a factory in Asia to a distribution center in the United States is calculated for five different products using two methods. The first method, a screening model, uses public information and readily available data to estimate the carbon emissions from warehousing, transportation, and port operations. These results are compared to those of Damco’s SupplyChain CarbonCheckTM tool, which makes use of more detailed information. Results show the screening model can produce significantly higher or lower emissions estimates depending on product characteristics. Furthermore, the screening model is unable to capture efficiencies from improved routing and container utilization.