The green soul of the concrete jungle: the urban century, the urban psychological penalty, and the role of nature

By 2050, there are forecast to be 2.4 billion more people in cities, and this century could rightly be called the urban century. This paper argues that, paradoxically, without the use of nature the urban century will fail. We review three literatures to assess the scientific support for this proposition. First, studies from economics show that it is the extreme potential for interaction that makes cities centers of productivity, innovation, and creativity. Second, many health studies document the increase in stress and greater prevalence of some mental disorders in cities, and we argue that it is the constant interaction of urban life that leads to this urban psychological penalty. Here we show that 46% of humans are living at population densities where global datasets suggest that this psychological penalty may be an issue, a fraction that will only grow as urbanization continues. Third, ecosystem service research shows that even a brief interaction with nature has mental health benefits, alleviating symptoms of this psychological penalty. Global datasets suggest that currently, only 13% of urban dwellers may be living in close enough proximity to nature to experience its mental health benefits. We argue that natural features in cities will be an essential part of the urban century, a way to have all the benefits of our urban, connected world yet also have that urban home be a place where we can psychologically flourish. We discuss two specific ways governments are trying to integrate nature into citizens’ lives, through Green Prescriptions and the Biophilic Cities Network.