Global, Mega, and Sustainable Cities: Key Concepts and Urbanization Trends

Introduction to Cities and Urbanization

• Cities/Urban Areas (US Census Bureau Definition): Densely developed territory with residential, commercial, and non-residential land uses.

  • Requires at least $2,000$ housing units OR a population of at least $5,000$. Urbanized Areas ($50,000+$ people), Urban Places ($5,000$ to less than $50,000$).

• Metropolitan Areas: Core urban area of $50,000+$ population, including surrounding integrated counties.

• Micropolitan Areas: Core urban area of $10,000$ to less than $50,000$ population, including surrounding integrated counties.

• Global Definitions: Vary by country, focusing on non-agricultural activities, population, density, and development.

History and Process of Urbanization

• Emergence of First Cities: Mesopotamia ([\sim$3,500$-$3,200$ BC), Ur (Bronze Age trading hub), Uruk.

• Classical Cities (Greek & Roman): Complex, advanced infrastructure, supporting large populations (e.g., ancient Rome reached $1$ million).

• Age of Urbanization: Accelerated by the Industrial Revolution, shifting from rural to industrial cities.

• Urbanization Process:

  • Urban Growth: Increase in urban population $(U)$.

  • Urbanization: Increase in the proportion of urban dwellers to total population $(U/T)$.

  • Urbanized Society: When (U/T) > 0.5. Over half the world's population currently lives in cities, with [\sim$82$ in the US.

Global and Mega Cities

• Sustainable Cities: Focuses on UN Sustainable Development Goal $11$ (SDG $11$).

• Global Cities: Key economic and connectivity hubs.

  • GAWC Research Network: Ranks cities by international connectedness.

  • Global Cities Index (Kearney $2020$): Ranks leaders by Business Activity, Human Capital, Information Exchange, Cultural Experience, and Political Engagement.

• Mega-cities: Cities with