The construction of electric lines and transmission losses occupy some weight in LCCO2 emission. However, the weight is still small, 25% at most, compared to the energy of water transportation and the total LCCO2 emissions from pipeline construction. If the seawater is supplied to cities without desalination, the recovery rate of RO is approximately 50%, and thus twice the energy is required for seawater transportation. Moreover, two pipelines must be constructed to return the concentrated seawater to the sea. In other words, as assumed in this study, it is more efficient to build a pipeline and an electric line from the desert to the sea, desalinate seawater at the seashore, dispose of brine water on the spot, and then transport only freshwater. However, there are also possibilities to devise ways to increase the recovery rate and to use hydroelectric power generation using concentrated seawater or pumped storage power generation. In addition, the construction of PV and thermal power plants at each of the desalination plant and ammonia synthesis plant locations can be considered. The cases without power lines need further studies.