This collection examines why urban environments are key sites for reimagining and reconfiguring human-nature encounters in times and spaces of planetary crisis. Cities constitute powerful and troubling spaces for human-nature intersections. They typically represent the effects of human dominance over nature: humans in control, taming and managing the wildness of 'nature' by domesticating it. Children existing in these mostly adult designed and orchestrated creations are often ignored as city dwellers, along with animals who increasingly migrate into urban areas. Yet cities are also sites of innovation and 'greening' , of critical democracy and renewal, with the most innovative cities including those where children co-create urban environments, and where animals and plants are valued as co-city dwellers. As this collection shows, troubling and reimagining these sites for diverse forms and ways of living, including of encounter with the other, and thus what can be learnt and taught through urban nature childhoods, is one possible pathway for working out different modes of being human with the earth. The idea for this collection on troubling and reimaging the deeply familiar concepts of urban, nature and childhood arose from a study visit to Berlin, Germany, where urban social, cultural, political and ecological initiatives are in constant tension with aggressive capital driven development. In Berlin, like in many of the world's cities, urban innovation (Ferguson 2014) co-exists with gentrification (Walsh 2013), urban food initiatives (Steele 2008), wildlife and cosmopolitics (Hinchliffe et al. 2005; Duhn 2017), brutal politics of expulsion (Sassen 2014), and with childhoods lived in poverty and childhoods lived in affluence (Chaplin, Hill, and John 2014). Berlin's politics of urbanity are at least partly about the 'renegotiation of the urban commons' (Ferguson 2014, 14; cf. the urban of Detroit, Johannesburg, Hangzhou, Lamu, Curitba and other case study sites of 'urban renewal' in Unesco 2016). Berlin's negotiations have led to discussions and debate, art works, architectural practices, discontent, disobedience and reclaiming as well as a re-imagining of KEYWORDS