Green spaces are social projects that reflect power relations, culture, class, and gender. As they are socially constructed, they also serve as arenas for struggles over environmental, social, and urban spatial justice. Considering the diversity of green spaces and the multitude of actors involved, this work seeks to identify and analyse how these spaces serve as platforms for new forms of participation that call upon new actors in the fight for socio-environmental justice in an urban context through two case studies. The current complexity of the climate narrative and contemporary socio-ecological issues, in which social inequalities are both a structuring and structured element, requires an analysis of these phenomena as a response to such challenges that may influence decisions on public policies at the local level.