This excel file is the cost model used for calculating costs related to ocean iron fertilization based on selected oceanographic parameters. It compares ship-based and aerial-based methods for delivering iron to the ocean for an application scale OIF effort. It also estimates costs related to verification. It sets three different parameter scenarios in the model, a best case, worst case, and intermediate case. The excel model is open so all parameters can be modified if a user wants to adjust certain parameters of interest to see the impact on cost. All costs are calculated as USD/tonne Carbon removed to the deep ocean for an unspecified time period but assumed to be of a decadal, centennial, or millennial timeframe.