This study provides a spatial accounting of ecosystem wealth associated with urban expansion across 210 cities in nine Asian countries. It delineates the natural extent of cities rather than administrative boundaries at 100 m resolution from GHSL between 1990 and 2025 to assess land cover affected by urban expansion through land cover transitions and encroachment in the vicinity of cities, using natural capital accounting from the IWI.

Three principal implications emerge.

First, city boundaries expand faster than the internal conversion of natural land to urban uses, indicating that natural-city-based governance frameworks better capture the environmental footprint of urban growth than administrative boundaries alone.

Second, population density within morphologically defined city boundaries remains approximately constant over time, suggesting that urban sprawl, rather than densification, characterizes the studied cities, with consequences, for per-capita ecosystem wealth.

Third, reductions in ecosystem wealth are most pronounced in large cities in Vietnam and Sri Lanka, and disproportionately affect high-value biomes, particularly grassland.

Together, these findings underscore the need for cross-boundary governance mechanisms and city-scale ecosystem accounting as foundational tools for sustainable urban planning in rapidly urbanizing Asia. It should be noted that we are underestimating the holistic effect on urban expansion since we are using conservative median values of ESVD which exclude other biodiversity or existence values.