Cities that green themselves: urban environments offset vegetation loss from expansion

Abstract

Abstract

Urbanization relentlessly consumes vegetated land, yet paradoxically, the remaining urban plants often exhibit enhanced growth. The net outcome of this trade-off, known as the growth offset, has been poorly quantified at a global scale. Here, we developed a new conceptual framework derived from near real-time heterogeneous urban landscape for characterizing the impacts of urbanization on vegetation growth. We applied it across 998 cities worldwide from 2001 to 2022 and evidenced the offset effects of urban environmental contexts (positive enhancement) to physical encroachment (negative replacement) on vegetation greenness and productivity. The results reveal a globally prevalent, generally positive growth offset, with no significant temporal fluctuations. The offset effects can compensate for ~41% or 31% of the vegetation loss due to urbanization (using greenness and productivity as proxy respectively). Landscape characteristics, particularly urbanization intensity, consistently imprint a strong and persistent signature on growth offset. Crucially, we project that strategic greening of gray infrastructure—such as rooftops and walls—can almost fully counteract the vegetation loss caused by urban expansion. Our findings reveal a critical, underappreciated opportunity for cities to mitigate environmental impacts, paving a clear pathway toward ecological resilience and carbon neutrality in an urbanizing world.