This paper examines how planning theory functions as a tool of environmental imagination in addressing sustainability challenges in the Global South. It reviews four planning theoretical traditions: collaborative planning, just sustainability, insurgent planning, and relational planning to show how theory shapes the framing, governance, and outcomes of sustainability interventions. Drawing on cases from Global South cities, the paper shows how planning interventions influence whose knowledge is recognized, how environmental risks are addressed, and which futures become actionable. It argues that planning theory remains central to sustainability practice when understood as an interpretive framework for navigating socio-ecological complexity, power struggle, and institutional constraint.
Stephen Biliyitorb Liwur (2026) studied this question.