Climate change is in the news frequently these days, and better-informed commentators note that changes in the water cycle pose the greatest challenge to society. We may be able to deal with an increase in temperature with a bit more air conditioning, but significant intensification in droughts and floods will be a more severe test. Civilization thrives at a range of temperatures at different latitudes, but it cannot cope without water. Thus, a number of national and international programs have been organized to assess and understand the "global water cycle." For the oceanographer, these programs have fallen short. The focus is invariably on the water cycle over land; generally, the much larger oceanic water cycle is ignored. This bias is understandable, because society's water needs are land based. But, to gauge the water cycle, it is impossible to ignore the ocean. The numbers speak for themselves: the ocean contains 97% of the free water on our planet, and 86% of the evaporation and 78% of the precipitation occurs over the ocean (Schmitt, 1995).
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