Jakarta has overtaken Tokyo as the most populated city in the world, reaching a population of almost 42 million people [1], [2].

This demographic shift highlights the extreme pressure on urban infrastructure in Southeast Asia. The surge in residents coincides with critical environmental threats that jeopardize the city's long-term viability.

The population growth accelerated after Indonesia gained independence in 1945 [1], [2]. The current figure of nearly 42 million [1] reflects the latest United Nations estimates, which utilize a methodology that counts peripheral districts within the Greater Jakarta metropolitan area, known as Jabodetabek [1], [2].

Despite its growth, Jakarta is sinking rapidly [3]. Experts said this subsidence is due to a combination of rising sea levels, chronic flooding, and the uncontrolled extraction of groundwater [1], [3]. As the land sinks, the city faces an increasing risk of permanent inundation in its coastal areas.

This environmental crisis is compounded by the sheer scale of the population. The city struggles with severe traffic congestion as millions of residents navigate a landscape where infrastructure cannot keep pace with urban migration [1], [3].

Local authorities and urban planners face the dual challenge of managing the world's largest urban population while attempting to stabilize a city that is physically disappearing into the sea [3]. The reliance on groundwater pumping has accelerated the rate of subsidence, creating a cycle of sinking land and increased flooding [1].

“Jakarta has overtaken Tokyo as the world’s most populated city”

The convergence of record-breaking population growth and rapid land subsidence creates a precarious situation for Indonesia's capital. The need to move millions of people or implement massive engineering projects to prevent the city from sinking underscores the urgent intersection of urban planning and climate change adaptation.