What makes a city a city? 

Historically cities have been defined as large settlements of people in a determined geographical area. Usually, the population in these urban areas can range between 1,500 and 50,000 people, but this number can vary significantly from country to country. Cities tend to be rich in cultural diversity and offer a large variety of jobs. This influx of economic activity is what brings more individuals into the cities. 

Back in the day in the UK, a city had to have a cathedral to be considered a city. 

According to the UN, the world’s cities occupy just 3 percent of the Earth’s land but account for a massive 60-80% of energy consumption and 75% of carbon emissions.


According to Macrotrends, Tokyo, Japan, is the biggest city in the world. Considered a megacity, Tokyo is home to 37 and a half million people. 

Megacities are those with a population larger than 10 million people. There are now 34 megacities in the world, and it is estimated that more new megacities will emerge in Asia and Africa by 2030. The challenge with megacities is that controlling crime, guaranteeing equal access to education and health services, and secure homes becomes more demanding and complex for both citizens and governments. 

Megacities are hot spots for inequality which can often lead to higher crime rates concentrated in specific areas of the city. In addition, rapid growth can make it difficult for the city to provide housing opportunities to all its citizens, often leading to homelessness and the creation of slums. Slums are overcrowded urban areas or inhabited by people who lack the resources and access to work, health and education. 

Where Are The World’s Worst Slums?

Link to video: https://www.youtube.com/watch?v=Q67gldZ1P_8&t=2s

New York City is the number one megacity in the US, with the current metro area population of 18,823,000, a 0.1% increase from 2020. 

However, it is not all bad news for New York. According to IESE Business School’s Centre for Globalization and Strategy and their “Cities in Motion Index 2020”, New York ranks number two in the “smartest and most sustainable city in the world” list, with Paris ranking number one. 

The cities are analyzed across nine dimensions: 

  • human capital (developing, attracting and nurturing talent); 
  • social cohesion (consensus among the different social groups in a city); 
  • economy; 
  • environment; 
  • governance; 
  • urban planning; 
  • international projection; 
  • technology; 
  • and mobility and transportation (ease of movement and access to public services)

New York City’s second place is down to the economy, urban planning, mobility and transportation (all position 1) and human capital (position 3). However, New York scored poorly in social cohesion (151st) and protecting the environment (69th).

Thinking Caps On
How can we make cities greener, better and more equal for all their citizens? Can you think of a list of necessities all humans have and how the government can make sure these are covered even in highly populated urban areas? What do you think are the biggest challenges in creating sustainable cities with access to green spaces, water, transport and jobs for all?

What are Sustainable Cities? 

A sustainable city offers a good quality of life to all its residents by ensuring access to education, equality, health, transport and green recreational areas. Also, it offers green energy options and solutions and infrastructure to support growth. 

A Sustainable City Offers: 

  • Resources and services accessible to all citizens. 
  • Public transport infrastructure, as an alternative to cars.
  • Public transport that is safe and reliable, with the integration of safe walking and cycling areas. 
  • Green open areas that serve as recreational space. 
  • Renewable resources or access to green energy options, such as solar and wind energy. 
  • Easy recycling available to all citizens 

Copenhagen, Denmark, Vancouver, Canada, and San Francisco, USA, are among the world’s most sustainable cities. In Copenhagen, around 62% of its residents use a bike as their primary outdoor transportation. The data they’ve gathered in recent years proved that cycling is incredibly beneficial to health and has helped reduce carbon emissions in the last decade. On the other hand, Vancouver is one of the first major cities in North America to join the 100% renewable energy movement. Currently, around 95% of state electricity is coming from renewable energy. In addition, the City of San Francisco was crowned the Greenest City in North America in 2011. It has since then made it its mission to fight pollution and waste from proper disposal of waste and carbon emissions to building eco-friendly houses and structures. 

What about your city? 

Is recycling encouraged in your city or local community? If so, do you help recycle at home by dividing waste into paper, plastic and aluminum? 

Can you think of ways in which you can help reduce waste at home and school?

Every little action can help build greener and more sustainable cities.