Urban areas face significant sustainability challenges,
including accommodating rapid population growth,
projected to add 2.5 billion people by 2050. This
growth increases demand for housing and services,
often leading to severe traffic congestion and higher
pollution levels. Additionally, cities, which consume
over 75% of global energy and produce more than
70% of greenhouse gas emissions, must transition
to sustainable energy solutions to mitigate climate
change impacts while addressing social inequalities
that leave vulnerable populations disproportionately
affected. To address these challenges, recent
perspectives on sustainable urban planning call for
a deeper understanding of cities as complex and
emergent socio-ecological systems. One such concept
is urban metabolism (UM) which has expanded from
its biological meaning to capture the metabolic
processes by which cities transform materials and
energy in order to sustain their functions. This paper
examines the role of urban metabolism in sustainable
city planning using detailed case studies of three
cities to determine how urban metabolism principles
are integrated into urban planning practices and their
effectiveness in promoting sustainable development.