1. The global population is projected to grow significantly by 2050, putting pressure on resources and consumption. Cities will need to accommodate billions of new residents and reduce their environmental impact. 2. Green cities focus on improving environmental sustainability and quality of life through reducing carbon emissions, waste, and resource use. Smart cities use technology to more efficiently manage infrastructure and services. 3. Every city needs a strategic system to determine the appropriate balance of goals like social cohesion, economic competitiveness, sustainability, innovation and governance styles based on their own assets and needs. Labels like "green" and "smart" are less important than designing a customized future for each city.