Just green resilience in desert cities integrating heat mitigation water efficiency and equity

Urban greening is increasingly positioned as essential climate infrastructure in hot-arid cities facing extreme heat, water scarcity, and socio-spatial inequality. However, it remains unknown how cooling performance, water efficiency, and equity outcomes interact across arid urban contexts in a consolidated evidence base. Here we establish a previously unresolved synthesis of urban greening strategies in U.S. desert cities to reveal how environmental performance and social equity can be jointly optimized under hydrological constraints. A PRISMA-guided systematic review synthesized peer-reviewed studies published between 2005 and 2025 across Phoenix, Las Vegas, Tucson, and Albuquerque (n = 52). Evidence was thematically coded across sustainability, climate resilience, equity, and governance, with 92% inter-rater reliability. Across studies, shade-based green infrastructure reduced ambient or surface temperatures by 2–5°C, while xeriscaping achieved 50–70% reductions in outdoor water use but delivered limited cooling (0.5–1°C). Equity analyses revealed a > 2-fold disparity in tree canopy cover and heat exposure between high- and low-income neighborhoods. Hybrid strategies integrating drought-tolerant shade trees with rainwater harvesting or recycled water systems demonstrated superior performance, resolving the trade-off between thermal comfort and water demand. Governance approaches emphasizing participatory planning and targeted investment were associated with more equitable outcomes, contrary to prevailing views that greening in arid cities necessarily intensifies inequality. This synthesis provides a new framework for just green resilience that integrates cooling efficacy, water sensitivity, and social equity in arid urban environments and paves the way for transforming urban greening from discretionary amenity into essential, equitable climate infrastructure for desert cities.