This book evaluates urban sustainability across various global cities, including megacities, cities in the Global South, Europe, North America, Middle East, North Africa, and Asia. It uses multi-criteria analysis with environmental, economic, social, and smart indicators to assess cities like London, New York, Hong Kong, and others. It focuses on climate change, poverty, renewable energy, and urban CO2 emissions. Case studies of cities such as San Francisco, Stockholm, and Seoul illustrate successful strategies and policies, offering insights for other cities and identifying investment opportunities in sustainable urban development.