Millions upon millions of people live in coastal cities — not just New York and the Boston-Washington corridor, Los Angeles, San Francisco, Miami, and New Orleans, but also many of the great cities in the emerging economies of Asia, India, and around the world. Their coastal locations are what fueled their growth in the first place, as a recent study titled "The United States as a Coastal Nation" [PDF] shows.
Cities, especially coastal ones, are critical components of the global economy. Just the world's 40 largest mega-regions — many of them located along coastline — account for roughly two-thirds of global economic output and nine in 10 of the world's innovations. The next several decades are primed to witness the greatest surge in urbanization in world history, and much of it will occur in coastal cities.