What is Population Density?

An important parameter that helps determine the strain on a particular ecosystem is population density. This parameter has been explained in detail, in this article.
It is hard to imagine that what was once one of the weakest of organisms on Earth, doomed for extinction, has one of the largest and most long-lived populations on the planet today. Can you guess who I am talking about? It is scarcely a surprise that this mammal is also the most intelligent creature on the planet. Yes, I am talking about the human race. Human evolution is a game of rising and falling populations and one of the most important statistical parameters for evaluating the impact of changing conditions on organisms is the calculation of population density.


In biological terms, population density is the number of organisms existing per unit area of land or water. By organism, I mean any plant or animal, from small microbes to the blue whale. In geography terms, it is the number of humans living in a region, per unit square kilometer. Density is generally calculated with respect to a city, village, state, country, or even a continent. The human population, which once numbered in thousands, a few million years ago, has today gone beyond a billion. In fact, world population growth has accelerated and is fast approaching seven billion.

The density of population in an area, calculated in terms of people per square kilometer is one of the prime indicators of the degree of development in an area. More favorable the natural resources in an area, more is the density of population. Not surprisingly, the lowest density in the world occurs in regions which are hostile to life like the area around the Arctic circle, Antarctic circle, and the desert regions of the world.

The highest density is always found around water bodies like rivers, with abundant natural resources. The rise and fall of density is thus dictated by the distribution of natural resources and the ability of humans to adapt to changing natural conditions.

World Human Population Density

The world human population is close to 6.8 billion currently. The total land area on Earth is about 150 million km2. So, if you calculate the world human population density, using the above two numbers, it comes out to be 45.3 per square kilometer. If you exclude the area of the Antarctic from the calculation, the world population goes up a bit, to 50 people per square kilometer.

This is the world average and it fluctuates severely from region to region. The region with the highest recorded density, according to the latest population counts is Macau, with 18,534 people per square kilometer. The region with the lowest density is Greenland, with a mere 0.026 people per square kilometer.

Asia and Africa remain the most densely populated continents. As the world population rises, there is increased pressure on the usage of natural resources and it is generating flash points all around the world. The human population is fast approaching a bottle-necking event, that is going to have a huge impact on the fate of our dear planet. Overpopulation problems are already evident in the big cities of the world.

We have multiplied exponentially in the past centuries, but never before has our race had such a direct impact on the fate of our planet. A high population density of organisms used to be achieved naturally due to struggle between competing populations for resources. However, we humans have outwitted all our competition and are fast depleting all the natural resources. Human greed needs to be put in check, if we intend to feed, clothe, and offer shelter to the billions of people around the world.