A system and method for optimizing order fulfillment by considering multiple supply modes in one aspect, plans supply of inventory by forecasting demand, estimating accuracy of said forecasted demand, and establishing reorder point policy based at least on said accuracy of said forecasted demand, a plurality of supply transportation modes, cost of carbon emissions and limit on carbon emission credits. Current inventory position is monitored and if the current inventory position is below the reorder point policy, orders are placed according to a selected shipping method. The selected shipping method may be based at least on customer order priority, transportation budget, and carbon emission limit.