Why Coastal Cities Are In Bigger Danger Than You Thought

One-third of the cities observed as part of this study recorded a subsidence rate of more than 0.4 inches per year, which is quite a concerning stat. Notably, high subsidence has been observed in both industrial and residential areas. Unregulated groundwater extraction is a recurring theme in almost all the at-risk cities, requiring urgent government intervention with proper policies to avoid the dire consequences if the problematic trend continues.

The double whammy of rising sea levels and an even faster rate of land subsidence only accelerates the risk of habitable land sinking sooner than what current climate change models predict. As per data compiled by NOAA and shared via Climate.gov, the global sea level reached a new record high of 3.6 inches in 2020, and the rate at which the sea level is rising is only accelerating. According to the World Economic Forum, Dhaka, Lagos, and Nigeria could have vast tracts of land submerged underwater by the yea 2100 if the rising sea level trend and land subsidence continues. 

Fortunately, not all is lost. With controlled groundwater extraction that was mandated by government regulations, cities like Jakarta and Shanghai managed to dramatically slow down the rate at which these cities were sinking. However, certain areas in these cities that are closer to the sea are still recording a subsidence rate of 0.4 to 2 inches per year based on line of sight (LOS) observations.