The world is in the midst of the largest wave of urban growth in history. With more than half the population already living in cities, and further rises expected, the health of city dwellers is crucial to global well-being.
Throughout history, many of the innovations designed to improve city living have instead posed a challenge to having a healthy, happy life (page S50). Urban environments designed around the car, for instance, promote a sedentary lifestyle (S52).
Faced with shifting climates, urban policymakers are preparing to deal with an increased risk of flooding (S54) — the replacement of concrete with more absorbent surfaces may be part of the solution. Evidence is also building that green space, although scarce, is a valuable resource for improving mental health — especially in poorer communities (S56).
Health inequality is the bane of many countries. A community project in California shows how tackling stress in deprived neighbourhoods can improve the health of people whose life expectancy often lags behind that of their richer neighbours (S58). Although improved living standards have reduced the toll of infectious disease over the years, the world's poorest urbanites remain vulnerable. From cholera to Zika virus, slums provide the ideal place for pathogens to thrive (S61).
Interventions to enhance urban living, such as city farming, are not without their pitfalls (S60). Although navigating the risks of urban improvement will not be easy, it is essential if we are to better the lives of the urban population (S64).
We are pleased to acknowledge the financial support of the Institute of Urban Environment, Chinese Academy of Sciences; Zhongke DingShi Environmental Engineering Co., Ltd; Ningbo Tianhe Aquatic Ecosystems Engineering Co., Ltd; and Huilv Landscape Construction Development Co., Ltd in producing this Outlook. As always, Nature retains sole responsibility for all editorial content.