Istanbul Among 48 Coastal Cities Sinking Under Pressure of Climate Change and Groundwater Overuse

A recent global study by Singapore’s Nanyang Technological University (NTU) has identified Istanbul as one of 48 major coastal cities worldwide experiencing land subsidence, driven by rising sea levels and excessive groundwater extraction. The findings, highlighted by the BBC, present a stark warning about the dual environmental threats facing rapidly urbanizing coastal zones.

Up to 13.2 cm Annual Subsidence Recorded in Istanbul

The study, covering the period between 2014 and 2020, revealed that various areas in Istanbul are sinking by between 0.01 cm and 13.2 cm per year. One of the most affected areas is Arnavutköy, the district that houses Istanbul Airport, which emerged as a notable hotspot for ground subsidence.

These figures underscore the vulnerability of critical infrastructure and urban planning to both geological and climate-related stressors.

Climate Change and Water Mismanagement: A Dangerous Duo

According to lead researcher Cheryl Tay, the sinking of coastal cities is primarily driven by two compounding factors:

“Nearly half of the world’s drinking and domestic water is sourced from underground aquifers. These same reserves are heavily exploited for agriculture. When extraction exceeds natural replenishment, it weakens the earth’s structure—causing the ground above to sink.”

Sea level rise, fueled by global warming, is compounding the issue. NASA recently reported that global sea levels rose by approximately 0.59 centimeters in 2024 alone, amplifying the threat to low-lying coastal regions.

A Global Problem: Data Drawn from Asia, Europe, and the Americas

The NTU-led study, supported by data from Istanbul Technical University and Freie Universität Berlin, examined satellite imagery and geological models to track urban land sinking trends. The analysis spans cities across Asia, Europe, and the Americas, warning of widespread risks to infrastructure, ecosystems, and water systems.

Policy Lessons from Tokyo

The researchers pointed to Tokyo as a success story in mitigation. Following early warnings about subsidence in the mid-20th century, Japanese authorities implemented strict groundwater regulations, significantly reducing land sinking.

This proactive approach, the NTU team suggests, offers a model for cities like Istanbul that are just beginning to grapple with the long-term consequences of groundwater mismanagement and climate change.

Urgent Need for Urban Resilience Planning

As coastal megacities like Istanbul face mounting pressures from climate change and overdevelopment, experts are calling for comprehensive urban resilience policies, including:

• Stricter groundwater regulations

• Sustainable water resource management

• Infrastructure planning based on subsidence data

Failure to act could lead to increased flooding, infrastructure damage, and displacement in some of the world’s most densely populated regions.