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2 Tutorials that teach Human Population Growth
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Human Population Growth

Human Population Growth

Author: Sophia Tutorial

Determine the amount of natural resources required for each person to live.

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what's covered
This tutorial will cover the topic of human population growth. We will discuss the state of human population growth today and the resulting environmental degradation. We will define our key concept, ecological footprint, and discuss the many types of environmental impacts of human population growth.

Our discussion breaks down as follows:

  1. World Population
  2. Environmental Degradation
  3. Ecological Footprint
  4. Ecological Impacts of Population Growth

1. World Population

The world's current estimated population is around 7.2 billion. As we can see with the graph below, only a little over 55 years ago that number was less than half of that figure, at around 3 billion.

World Population Graph

Another way to view this is shown in the world population map below. This map colors a country based on its population. The darker the color, the higher the population. Developing countries, like India and China, are much more populous than countries like the United States, because they are still in the lag time where death rates are dropping but birth rates are still very high.

World Population Map

2. Environmental Degradation

The current population of the world, at 7.2 billion, is considered by many scientists to be unsustainable. Humans are a major cause of environmental degradation, as we dig for fossil fuels and deforest areas for meat production.

Unfortunately, in countries where people are poorest, populations tend to be highest. This combination usually results in people having no alternative but to degrade their local ecosystems in order to provide for themselves. Humans' rate of resource consumption and environmental degradation is increasing proportionally to our population growth.

big idea
Essentially, we have a big problem. Our planet has a finite amount of land, water, and energy resources, some of which are renewable and non-renewable. Unfortunately, at our current rate of growth and consumption, we are using up our non-renewable ones, such as fossil fuels, and degrading our renewable ones, such as safe drinking water and forest land.

Land resources Water resources
Energy resources Energy resources

Referring again to the world population graph up above, the UN projects three possible futures of population growth by 2100: based on low (green line), medium (orange line), and high (red line) birth rate projections. The impacts on our environment and human quality of life will vary dramatically, depending on which of the scenarios becomes reality.

3. Ecological Footprint

When talking about human population growth and its relationship to the environment, it is important to understand our key concept for today, known as the ecological footprint. Ecological footprint is the amount of resources required to sustain an individual or a population.

It is usually measured in hectares, which is a measurement of land area equal to 10,000 square meters. It is the metric system equivalent to acres.



In the United States, the average standard of living creates an ecological footprint which requires five hectares of land area per person. This is similar to about nine football fields of land.

United States

According to the World Bank, the United States currently has 0.5 arable hectares of land available per person. This means there is less land available in the U.S. than we require with our average standard of living. This is made possible because much of the land which supports the U.S. standard of living is borrowed from other countries, by importing much of our food in commodities.

In other developing countries, such as India, the average standard of living requires only 0.5 hectares of land, which is less than 1 football field.


If the entire world population required the same standard of living as the United States, we would need three Earths to support it.

term to know

Ecological Footprint
The amount of natural resources required to sustain an individual or a population.

4. Ecological Impacts of Population Growth

There are many types of environmental impacts of human population growth.

Environmental Impacts Description
Atmospheric pollution Pollution from cars and industrial processes have caused significant atmospheric pollution all over the world.
Climate change CO2 production has altered the planet's heating and cooling systems, creating a phenomenon called climate change.
Water pollution Safe drinking water resources have been polluted, preventing millions of people all over the planet from having any safe drinking water.
Threatened biodiversity Sprawl of cities and farming has destroyed habitat and food resources, threatening the biodiversity of our ecosystems and causing millions of species to go extinct, even just in the last couple of centuries.
Overexploitation Too much hunting and fishing has also endangered species.
Deforestation Meat production and agriculture have caused huge swatches of forest to disappear, which only increases the impacts of climate change and air pollution.
Resource depletion The resources needed to support and maintain developed nations' lifestyles are resulting in the depletion of non-renewable resources, such as fossil fuels and various rare materials.

Today we learned about human population growth — how it has dramatically increased in the last century and how it is having negative environmental impacts on our planet. In places like India and other developing countries, population growth is high, along with poverty. The result is a much higher rate of environmental degradation, as people try to provide for their basic needs. If humans all required the same standard of living that people have in the U.S., we would need three entire Earths, which is a very large ecological footprint. Speaking of which, don't forget the key term for today, ecological footprint, which is the amount of natural resources required to sustain an individual or a population.


Terms to Know
Ecological Footprint

the amount of natural resources required to sustain an individual or a population