Green dose to resilient and equitable urban health

Urban health stands as one of the defining challenges and opportunities of our century. As cities continue to expand and densify, the well-being of their inhabitants is shaped not only by the bricks and mortar of urban form but also by the green and blue spaces that thread through our daily lives, the shifting patterns of infectious disease, and the social and economic structures that govern access and equity. This issue of Nature Cities brings together a set of manuscripts that collectively shed light on these interwoven pathways through which urban environments influence human health.

Cities are paradoxical spaces. They concentrate aspects such as opportunities and risks, innovation and inequality, and connection and isolation, among others. As we grapple with rising rates of mental health challenges, chronic diseases and environmental health threats, an increasing scope of research reveals that green spaces within cities are not merely amenities; they are vital components of urban health infrastructure.

A central thread in this issue is the role of green spaces in supporting mental health. The Article by Jiang and coauthors challenges the simplistic notion that “more is always better” when it comes to urban greenness. By synthesizing four decades of research, they reveal that moderate doses of greenness deliver the greatest mental health benefits, whereas both too little and too much can be less effective or even counterproductive. Building on this, the Article by Li and colleagues presents a global synthesis demonstrating that both active and passive contact with urban forests and parks yield substantial reductions in negative psychological states, such as feeling depressed or anxious, and promote positive states such as vitality and vigor. Notably, young adults seem especially sensitive to these benefits, a finding with implications for prevention and early intervention.

The importance of getting this balance right extends beyond individual mental health to encompass the broader ecological health of cities. The Article by Moreno-García and colleagues introduces a framework for understanding interactions among urban species, providing crucial context for why urban nature matters for human health. Their model examining species presence, co-occurrence, and actual species interactions reveals how urbanization disrupts the ecological processes that ultimately support human well-being. Urban stressors such as heat islands, pollution and habitat fragmentation do not just affect individual species; they cascade through ecological networks, potentially compromising the ecosystem services on which urban health depends.

Emerging infectious threats are an integral component of urban health. The Article by Lou and coauthors turns the spotlight to the shifting landscape of infectious disease, tracing the northward expansion of scrub typhus in Jiangsu Province, China. Their analysis reveals that urbanization is accelerating the spread of this vector-borne disease into new temperate and urban areas, while demographic trends such as population aging exert a complex, counterbalancing effect.

Yet, disparities in access and opportunities persist throughout the urban landscape. The Correspondence by Soni calls for “restorative access zones” in Indian cities, arguing that biodiverse, accessible green spaces must reach informal settlements and marginalized communities if the mental health benefits of nature are to be realized at scale. The Correspondence by Buckley and coauthors warns that even when green spaces exist, social, cultural and economic barriers — from poverty to unfamiliarity and lack of transport — can block access for those most in need.

Taken together, the manuscripts in this issue make clear that urban health is shaped by a web of interdependent factors — physical environment, social context, ecological change and demographic shifts. The evidence is compelling: interventions that enhance urban nature can yield measurable mental health gains but must be tailored to local contexts and population needs. At the same time, vigilance is required to anticipate and manage new health threats that emerge from the process of urbanization and climate change. Across all these aspects of urban health, equity emerges as key, as access to high-quality green space, resilience to infectious disease and the ability to benefit from urban health interventions are unequally distributed, demanding intentional design and sustained investment.

As cities continue to grow and change, so too must our understanding of health. With this in mind, we continue to encourage submissions about cities and urban issues that explore the intersections of environmental change, social vulnerabilities and human health outcomes. We also invite you to follow and contribute to the new journal Nature Health, to be launched in January 2026, ensuring that the science and practice of public health remains at the forefront of global innovations.