Storms aside, most of us associate the sea with pleasure. In my case, I was taken to Jones Beach on Long Island as a child: first encounter with surf, family picnics ,sun-tan lotion, laughter. Growing up near New York City, I recall watching ocean liners gliding down the Hudson. A group visit with a college professor to the “Dry Salvages,” rocks in the sea off Boston, with a reading of the T.S. Eliot poem. When I moved to the West Coast, sunsets over the Pacific. A honeymoon on the beach in Hawaii. Anyone who has lived or vacationed on the coasts has similar memories.
But the sea is rising. If all the ice in Greenland melted, the global rise would be about 25 feet.
So far, the main characteristic of sea-level rise is its extreme gradualness. Of course, this almost imperceptible process is broken by floods and storm-surges. but in between, life seems almost normal.
Over the long term, how can low-lying coastal cities adapt successfully to rising seas? One way is to go directly from negligence or denial to panic. There are other ways. Probably the mildest is flood insurance, which could be made compulsory, at least in the most vulnerable zones. However, the premiums would eventually rise to unsustainable levels.
New building may be prohibited in areas most vulnerable to both storm surges and floods, which would affect more and more areas.
What about moving elsewhere? In investing there is the phenomenon of the “greater fool.” Crashes come when the system runs out of greater fools with money. Until then, however, the system may go through sets of greater and greater fools. No reason why something similar would not apply in real estate. You might expect residents to pay attention to science and to think ahead, but you might expect voters not to support a con man.
When a building has a shorter life because of rising seas than because of inherent aging, some owners may try to sell and, because of a generally rising market, may even get as many dollars as they paid, (if not dollars adjusted to inflation).
Homeowners and even neighborhoods may invest in dikes and sea-walls, where possible, which might be effective against flood and surges, if not against the constantly increasing sea-level. However, when streets are permanently flooded, how will the occupants get to work or the store? How will traisn get through?
To preserve usable infrastructure, a city may need, at great expense, to erect a seawall protecting the whole area. This would require an increase in taxes. The city budget would then include not only police and a fire departments, and all the other services currently provided by cities, but also huge construction project, including dikes.
One alternative would be to let a city of high-rises flood and provide water transportation above what once were streets. The basement and the first floor or whatever would need to be sacrificed, the facilities in these levels to be replaced, underground city services to be rebuilt at a safe height, and docks be provided for each building. I am not an engineer and do not know whether the foundations of high-rises could be be safely submerged, but to the extent this could be done, the only question as always is “who pays?”
This might work for 30-story buildings, but not for homes. Of the building, the loss of to stories is only about 7%, while in a typical home, it would be everything but the attic. And besides, many homes would simply rot in water.
Or the city could be abandoned. This could take several forms: (a) individuals leaving jobs and old neighborhoods and moving to another city located on higher ground, (b) a city giving up and being abandoned, (c) a city trying to rebuild all or part of itself elsewhere, perhaps on adjoining higher ground.
The Chinese government has the experience of moving whole cities up hill when building a dam on the Yangtze River. It was known exactly how far the water would rise, and once the dam was built, the rise would be fairly rapid. Of course the Chinese had the advantage of an authoritarian system that could simply demand that the move take place.
On an individual basis, the most likely to move are young people just staring a career, and retired people who are willing and can afford to live in another place.
In any case, property-owners in a doomed city or area will suffer a collapse in the value of what may be their biggest asset, their house. When the value is less than the remaining mortgage, they may turn in their keys, as in the recent housing collapse, in which case not only will they be hurt, but so will the banks that hold the mortgages.
Going back to sale of houses before most or at least some buyers have realized what the future holds, the sellers can then buy houses in a new place, which may be another city or high-enough ground in the same city.
While growing up in the Northeast, I rode various water-level routes, and of course took the subways in New York and Boston, and later in the San Francisco Bay Area, lived in low-lying places in the City and the East Bay. In addition, I’m aware that many airports in coastal areas are built on land barely above the current sea level.
In addition, port cities would have a special problem: a “crust” of no-longer-usable docks that would be gradually submerged, necessitating new construction in order to move goods onto and off of ships, new construction that would have to be repeated with each substantial rise in sea-level.
Anything that would be hard in the U.S. would be even more daunting in countries that are less affluent, which of course includes most of the world. To what extent would countries treat the rising sea as a national challenge, and to what extent would national governments leave the cities and their inhabitants to their own misery? Would port cities get the same treatment as Puerto Rico? If not, what would be the national help? To individuals who have to move? To businesses? To municipalities?
Moving a city or part of it would be expensive just in terms of construction costs, but a city is much more than residences; for example, it is jobs. Thinking of the long term, what would be the least costly solution that would impose the least suffering?
We don’t know how quickly the waters will rise. Models are uncertain. Some scientists even foresee “abrupt” climate change, caused, for example by the release of methane clathrates (a frozen form of the gas) under shallow portions of the warming Arctic Sea. (Methane is a greenhouse gas much worse than carbon dioxide, and all greenhouse gases cause a self-reinforcing feedback loop.)
In the U.S. much of the financial world, media headquarters, and naval bases and some other parts of the Federal government are barely above sea-level. In places where I happen to have lived, residents are accustomed to blizzards and hurricanes or fearful of earthquakes, but they have always had a constant sea-level.
Sea-level rise will not be the only challenge of climate change, but for low-lying coastal cities it will be an inescapable issue. It will be gradual but inexorable. Whoever pays, the adjustment will be costly. Can we invent forms to make the change as fair and wise as possible? The time to prepare is before the waters are lapping at our infrastructure, much less our homes.
Sea-level rise reminds me of a progressive illness that proceeds very slowly. It is hard to know when the increasing effects have made life quite limited. Most coastal cities will just lose low-lying areas, at least at first, but some will be isolated or even submerged by the sea. When does the adaptation become so difficult and unsatisfactory that abandonment is the only alternative?