Approximately 75 percent of the earth's surface is covered in water. so why, based on the information in the table below, is water considered such a precious resource? a. each year, more freshwater is being trapped in icecaps located at the north and south poles. b. global warming caused by greenhouse gas emissions will likely cause earth's oceans to evaporate. c. the greenhouse effect is causing most of the world's freshwater to be trapped in the atmosphere. d. only a small fraction of the earth's water is freshwater available for drinking and irrigation.