right, except that humans have fixed the high tide lines over whole geolographical areas and done massive work to redirect almost all of the rivers and streams to agriculture, industry and domestic uses, and stopping most of the sand from reaching the ocean, plus sand mining for building is so extensive that there now shortages, meaning that the main surface sources are gone. those fixed high tide lines are also the collateral for trillions of dollars in loans and investments, and given the tripple wammy described in the article, things could get out of hand in a whole new way.