Period Four (1946–1999) marked Sydney’s first metropolitan planning scheme in an age dominated by the automobile. The population ballooned following World War II, reaching four million by 1999 and driving rapid urban expansion and a growing environmental footprint. Facilitated by cheap oil and widespread car ownership, the city decentralised to spread outwards. This era saw socioeconomic changes, including women more substantially entering the workforce, higher living standards and a shift away from manufacturing towards a white-collar economy. Accompanying economic prosperity, pollution and ecological degradation increased, albeit increasingly offshore. Urban planning sought to manage growth patterns, evolving from the visionary 1948 County Cumberland’s Planning Scheme, to align with neoliberal agendas prioritising prosaic economic expansion. While technological advances brought prosperity, they also raised concerns over unsustainable modes of production and consumption. Overall, large swathes of former agricultural lands were rezoned for urban development in an increasing economic game of peri-urban land speculation. This diminished the city’s available production lands and local and per capita food supply security.