The invention discloses a method for reducing the global temperature, comprising a barge, a belt conveyor and a water pump, characterized in that the following steps are taken: a) transporting a number of empty barges to a region covered with ice floes in the north and south poles, and then using belt conveyor to load the accumulated ice floes into the empty barge; b) drives the barge loaded with ice to the nearest desert country; c) builds more than one reservoir on the desert coast, and a number of artificial canals were built in the sluice of the reservoir; these canals run through the desert to form a hydraulic transport network; d) drain the melted ice water to the reservoir on the coast by gravity or a pump, and open the sluice; ice water flows into the canal, and trees or grass are planted on both banks of the canal.