The world’s coastal cities are sinking, and climate change has little to do with

Many coastal cities around the world are sinking Much faster than sea level riseso climate change will not have much to do with this phenomenon, according to recent study Published in Geophysical Research Letters.

The investigation indicates that many of the most important coastal cities in the world, such as Miami, Saigon and Jakarta, are drowning as a result of the sinking. Changes in your soil material Produced, in most cases, by human action, such as oil extraction Pumping gas or ground water. In these cases, during fluid extraction, the ground shrinks and the weight of the structures on the roof gradually sinks into the ground.

The study surveyed 99 coastal cities around the world, and found that 33 of them are sinking at a rate of more than one centimeter per year, five times the rate of sea level rise. This has forced some countries to take exceptional measures, such as Indonesia, which is moving its capital from Jakarta on the shores of the Java Sea, To a newly built city on the island of Borneopartly because the former is sinking more than three centimeters a year.

Study authors warn that current contingency plans for flood Implemented by many of these cities only take into account sea level rise, so these projections may cause cities They suffer unexpected disasters And we see some of their areas are using up water much sooner than expected.

Despite the variety of causes of city sinking, researchers have found that in all cities of the world the main cause is excessive pumping of groundwater, and they note that if this is controlled, the process may slow down. For example, Jakarta itself has gone from sinking 28 cm per year to only three since the Indonesian government Create a tighter regulation on groundwater extraction.

Other affected cities

The fastest sinking city is Tianjin, China, at a rate of 5.22 cm per year, followed by Semarang (Indonesia, 3.96 cm), Jakarta itself (3.44 cm), Shanghai (China, 2.94 cm) and Saigon (Vietnam, 2.81 cm).

The cities most affected by drowning are in Southeast Asia, and in fact, among the ten most drowned cities in the world, 9 divided between Asia and Oceania And only one, Houston, in the United States, belongs to another part of the planet.

For cities already suffering the consequences of the sinking, India’s Bombay stands out, sinking at a rate of 0.8 cm per year and every monsoon season. Suffers from the worst floodsBecause of rising sea levels and rain. fact, study In this city, approximately 2,500 buildings have been identified as at risk from sea level rise during high tide by the year 2050.

picture | Jonathan Ford