Estimating the Area for a Megalopolis Housing the World's Population

Imagine a single city that can house the entire world's population. To estimate the area required for such a megalopolis, we need to consider current world population figures, typical urban population densities, and some real-world examples. Let's begin with the current world population and go through the necessary calculations.

Current World Population

As of 2023, the estimated world population is approximately 8 billion people. This massive number presents a daunting challenge in terms of urban planning and sustainable development.

Population Density

The density of any given city can vary widely, but for densely packed urban areas, a typical density might be around 100,000 people per square kilometer. This figure is comparable to megacities like Tokyo, which consistently ranks among the world's most densely populated urban areas.

Calculating the Area

Using the simple formula for area based on population and density:

Area Population / Density

Plugging in the values based on the current world population:

Area 8,000,000,000 / 100,000 80,000 square kilometers

This calculation suggests that a megalopolis capable of housing the entire world's population would need to cover an area of approximately 80,000 square kilometers, which is roughly the size of the U.S. state of South Carolina.

Different Perspectives: London as a Reference Point

Don Scult has written an interesting answer, considering a more densely populated city like London. Let's explore this perspective.

London Inside the M25 Motorway

London is a unique city due to its vast green spaces, numerous parks, and a relatively medium population density by global standards. Consider the area inside the M25 motorway, which covers 2,580 square kilometers and has a population of 10 million. The density here is approximately 3,875 people per square kilometer. This provides a different context for urban planning and population density.

With the current world population of 7.5 billion devided by 3,875 people per square kilometer, the required area would be:

Area 7,500,000,000 / 3,875 ≈ 1,952,380 square kilometers

This area is significantly larger, equivalent to the size of Mexico, which is about 1,964,400 square kilometers.

Conclusion

The concept of a megalopolis housing the entire world's population raises numerous questions about urban planning, sustainability, and the practicality of such a massive city. Whether using a high-density city or a more sprawling, green urban area like London, the scale and impact of such a megalopolis would be monumental.

While the idea is fascinating, it also underscores the challenges of urban development and the need for smarter, more sustainable approaches to housing and managing large populations.