Across nine Asian nations, a quarter-century of urban growth has quietly consumed billions in natural wealth — not merely land, but the living systems that filter water, store carbon, and sustain life. A new study reveals that the true ecological footprint of cities like Bien Hoa far exceeds the administrative lines governments use to measure their own impact, rendering the real cost of expansion invisible to those responsible for managing it. By translating ecosystem loss into the language of economics, researchers hope to make visible what development decisions have long left unpriced — and