The Forgotten 71%
Oceans cover 71% of the Earth's surface and contain 97% of the planet's water. Over 20% of the world's petroleum is derived from offshore sources and 95% of world trade by weight, or two thirds by value, is carried by ship. Eighty percent of the world's fish catch comes from the ocean, supporting the livelihoods of 140 million people. Economists have calculated that the world's oceans provide services to humanity valued at US$21 trillion, as opposed to only US$12 trillion provided by land.
Geographers have long urged that attention be drawn to this space. Reflecting on Strabo's comment some 2000 years ago that ''we are in a certain sense amphibious, not exclusively connected with the land, but with the sea as well,'' Ellen Churchill Semple noted in 1911, ''Our school textbooks in geography present a deplorable hiatus, because they fail to make a definitive study of the oceans over which man explores and colonizes and trades, as well as the land on which he plants and builds and sleeps'' (Semple, 1911). Forty years later, Richard Hartshorne (1953) declared that ''the fundamental error in popular geographic thought'' (Hartshorne, 1953: 382–393) was the tendency to view the ocean as simply a barrier rather than as a space of human society. Nonetheless, few geographers have heeded their call.
The ocean has failed to attract attention from more than a handful of human geographers for three likely reasons: first, despite the fact that geographers have long critiqued the idealization of the state as a naturally occurring, organic entity, geographers (and, more generally,social scientists) still have tended to conceive of the world as a universe of state territories. As a space that lies primarily external to the territory or sovereign authority of individual states, the ocean thus has appeared as a space that is external to the space creating processes of society. Second, human geographers (and, again, social scientists more generally) have tended to view societies as occurring in place. Key social activities, such as production, reproduction, and consumption, as well as the cultural forms that support these activities, traditionally, have been associated with discrete places or territories. Movement typically has been viewed as a derivative activity that occurs simply because an individual or a commodity requires relocation from one society place to another, and little attention, therefore, has been directed toward the spaces across which this movement occurs. Thus, notwithstanding the ocean's substantial economic value as the space across which the bulk of the world's commerce flows, it has received little attention from human geographers.
Third, human geographers traditionally have viewed nature as ontologically distinct from society. Although geographers have long focused on the intersection between nature and society (examining, for instance, the way in which a place's nature and its society impact each other), this emphasis on the intersection between nature and society has tended to direct human geographers' attention away from spaces of nature that fail to display a clear human presence. Thus, as a space that is without permanent human habitation and that long was thought to be immune to human impact, the ocean typically has escaped the attention of human geographers who study nature–society relations.