• Sustainable cities
• Smart cities
• Smarter eco-cities
• Smart sustainable cities
• Artificial Intelligence of Things (AIoT)
• Generative Urban Artificial Intelligence (GUAI)
• City Brain
• Urban Digital Twin (UDT) 
• Internet of City Things (IoCT)
• Artificial Intelligence of City Things (AIoCT)
• Urban Circular Metabolism
• Platform urbanism 
• Environmental sustainability
• Environmental planning
• Environmental governance 
• Climate change mitigation and resilience
• Sustainability transitions
• Renewable energy and energy efficiency
• Sustainable and smart transportation 
• Sustainable and smart waste  management 
• Technological Innovation Systems (TIS)