Jakarta

city · earth

Indonesia's capital and, under the Degree of Urbanisation method adopted in World Urbanization Prospects 2025, the world's most populous city at close to 42 million people — a ranking that reflects how the urban agglomeration is now delineated as much as it reflects growth, since the same city stood 33rd on the previous method. Jakarta is also the clearest live case of a city whose binding constraint is physical. Large parts of it are subsiding, with recent assessments putting the citywide average around three and a half centimetres a year and North Jakarta considerably faster, driven principally by groundwater abstraction from an aquifer being drawn down because the piped network never reached the whole city. Subsidence and sea-level rise are additive at the coast, and the flood defence response — a coastal wall along the north shore, partially built and years behind schedule — protects the ground while the ground continues to fall. Jakarta is the reason Indonesia decided to build a new capital, and it is not going anywhere.