• industrial ecology;
  • Los Angeles River;
  • socio-ecological planning;
  • sustainable citizenship;
  • sustainability

Contemporary cities are unsustainable, compromising the health and well-being of coming generations. How can geographers help imagine and build cities that hold more promise for the future? I suggest that the answer lies in addressing three fundamental challenges facing society today: restoring the city's ecological integrity, redesigning systems of production and consumption, and recasting urban citizenship to promote social and ecological justice. Using the example of the Los Angeles River, I explore how multidisciplinary urban geographic research can help us think about these challenges, and contribute to the development of greener, more sustainable cities.