Adaptations of Coastal Cities to Global Warming, Sea Level Rise, Climate Change and Endemic Hazards - Structures That Protect Coastal Populations, Assets, and GDPs: Sea Dikes, Breakwaters, Seawalls
In 2018, about one billion people of the Earth’s 7.6 billion lived in marine coastal zones. The people, their property, and the infrastructure that supports them, and a city or national per capita GDP are at risk at multiple levels. These include coastal erosion, high and spring tides that cause lowland flooding, weather-related events (storm surges, flooding, wind, crop loss, unprotected anchorage, stabilization of navigation channels, and rarely, killer tsunamis). These coastal zones now, and more so in the future, are likely to be at high risk because of global warming-driven sea level rise. Human activity inshore can increase the level of risk from the above cited sources, such as flooding by abetting subsidence because of overuse of coastal aquifers for a water supply. Dikes, breakwaters, sea walls, and related structures are designed to thwart for some time (50 years?) damaging, destructive forces that assault coastal regions worldwide. They are costly to build and maintain but in short and long terms present economic benefits that preserve much, much more in capital investment.