To restrict groval warming by utilizing deep water for growing ocean plants by using the deep water as warm waste water after heating it with a thalassotherapy facilities, cryogenic supply plant or the like to be used for cryogenics of ocean deep water taken at water intake portions.

Ocean deep water from a header 20 of a water intake.water disposal plant 1 is pressured by a booster pump 27a in an electric power plant 3, and it is partially supplied to an intercooling equipment 28. Next, air sucked by an air compressor 29 is cooled and output of a gas turbine 30 is increased and a cylindrical shaped reverse osmosis membrane with a diameter of larger than 1 cm is used as a demineralizer 33. Also, an exhaust gas supply tube 37 of a marine tree planting plant 8 is connected to an electric power plant 3, and exhaust gas expanded at a gas turbine 30, particularly carbon dioxide, is supplied to the marine tree planting plant 8. And carbon dioxide is solidified and absorbed by photosynthesis of marine plants and effective utilization of cleanliness and cryogenic energy of ocean deep water is performed thereby promoting to invite new industries and offering a field of resting to the community residents. In this way, greenhouse effect on the earth can be reduced.