Major cities worldwide are sinking, satellite data reveal

What happened

Land subsidence is the gradual sinking of the ground, which can damage buildings, foundations, and drainage and sewage systems, and may increase flood risks. However, information on land subsidence dynamics remains limited, which makes it difficult for policymakers to identify where risks are intensifying and where urgent intervention may be needed. Previous assessments have often used different methods or time periods, or focused only on small numbers of cities, which has made global comparisons difficult.