Human Population Update: What is Our Ecological Footprint on this Planet?

I am a member of two LinkedIn groups focused on global issues and the future. In one of them the discussion has moved to defining our ecological footprint on the planet and comparing different areas of the world to come up with the planet’s carrying capacity.

What is ecological footprint? How is it measured? What are the implications of it in real world terms?

As our human population continues to grow will we outstrip the Earth’s carrying capacity or find sustainability in balance with the planet’s resources? Source: Footprint Network

Ecological Footprint – is the amount of resources needed by a single individual to survive. By inputting a wide range of data scientists have calculated the current human population’s ecological footprint as equal to 1.5 Earths.

Those who measure the ecological footprint include Mathis Wackernagel, currently President of the Global Footprint Network,  and William Rees, a researcher at University of British Columbia in Canada. They first defined the term and attempted to calculate what would be the equivalent unit of area needed by each human to maintain that individual’s current style of life. They called these units global hectares. A global hectare takes into consideration cropland, grazing area, forest lands, fish habitat, carbon output and urban space requirements to sustain a human. Since 1993 there has been continuous monitoring of the ecological footprint with some startling statistical results which you can see in the following table. In selecting the data presented here I have included all regions of Earth and representative countries from each region.

Country/Region Population (millions) Ecological Footprint 2008 (Global Hectares/person)
High-Income Countries

1,037.0

5.6

Middle-Income Countries

4,394.1

1.9

Low-Income Countries

1,297.5

1.1

Africa

938.4

1.4

Nigeria

150.7

1.4

Republic of South Africa

49.3

2.6

Middle East/Central Asia

382.6

2.5

Afghanistan

29.8

0.5

Israel

7.1

4.0

United Arab Emirates

8.1

8.4

Asia-Pacific

3,725.2

1.6

Australia

21.5

6.7

Bangladesh

145.5

0.7

China

1,358.8

2.1

India

1,190.9

0.9

Singapore

4.8

6.1

South America

390.1

2.7

Brazil

191.5

2.9

Colombia

45.0

1.8

Central America/Caribbean

66.8

1.7

Cuba

11.3

2.5

Haiti

9.7

0.6

North America

448.9

6.2

Canada

33.3

6.4

Mexico

110.6

3.3

United States

305.0

7.2

Europe

733.2

4.4

Albania

3.2

1.8

Bulgaria

7.6

3.6

Germany

82.5

4.6

Netherlands

16.5

6.3

Russia

143.2

4.4

The totals in the right-hand column may surprise you in the case of some countries. For example compare Germany to the United States. Both countries enjoy very high living standards but Germans consume far fewer resources to sustain their lifestyle than Americans. In Africa, South Africans use almost twice the resources of Nigerians. And in Asia-Pacific Australians use more than seven times the resources of people in India and nine times of those living in Bangladesh.

Our ecological footrpint combines food, water, habitation, energy and biodiversity to come up with a calculation measured in global hectares.                     Source Learninghood.ca

How Does Ecological Footprint Relate to Carrying Capacity?

First of all, what is carrying capacity?

Carrying Capacity – is the maximum population that the planet can sustain taking into consideration availability of food sources, water, and all the other necessities to sustain life.

You can calculate it by figuring out how many calories the planet can produce from all sources, agricultural and natural, crops, fish and fowl.

The following exercise is for illustration and not meant to suggest that the planet has lots of room still on it for human beings. We have chosen rice to do our calculations. Why that crop? Because it is grown by half the world’s population and accounts today for 20% of the total human caloric intake.

So let’s begin by starting with the number of calories an average human needs for daily survival.

2,000 calories

We multiply that by 365 days per year and the total comes to:

730,000 calories

Now we determine the total amount of fertile land that can be planted in rice. For this exercise we are going to use the total inventory of arable land on the planet. That number is:

38,488,090 square kilometers

Rice produces 1,250 calories per square meter. There are 1,000,000 square meters in a kilometer. So the rice calorie yield rate per square kilometer amounts to:

1,250,000,000 calories

Multiply that by the number of square kilometers and you get the optimal number of calories that we can produce annually growing rice. And the number is:

48,110,112,500,000,000 calories

Now divide this last number by 730,000, the number of calories one human needs to survive over a year, and voila, you have the theoretical carrying capacity of the planet.

Are you sitting down? Based on our calculation the number of humans this planet would support eating rice daily each year amounts to:

65,904,263,698

That’s almost 66 billion of us. Currently there are 7 billion humans on the planet so theoretically we still have a way to go before we max out on population, that is, if all we want to do is eat rice. Of course there are lots of factors that reduce this potential carrying capacity number. These include:

  1. Continued population growth in areas of the world currently already suffering from population stress
  2. Freshwater stress including water usage competition between urban and rural environments
  3. Reduced agricultural land from poor farming practices
  4. Deforestation
  5. Desertification
  6. Climate change
  7. Rising sea levels

And war, disease, pestilence and plague.

For humans in the 21st century it is clear that we cannot continue to have one part of the planet consuming at an unsustainable level while other human populations subsist on very little but it is also true that there remains some wiggle room to give us time to fix the problem. All it takes is global leadership focused on sustainability. But if the recent Rio+20 conference is an example of what our leaders are capable of doing then we need to find others to provide us with guidance to achieve our common planetary goal. National self-interest cannot continue to impede all of humanity. We are a global society and we need to make global decisions about managing our ecological footprint. That way we can find a sustainable medium for all in the remainder of the 21st century and beyond.

 


Len Rosen lives in Toronto, Ontario, Canada. He is a researcher and writer who has a fascination with science and technology. He is married with a daughter who works in radio, and a miniature red poodle who is his daily companion on walks of discovery. More...

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  • Hal Millegan

    Thanks Len.

    I appreciate what you have done. Your Blog has reached many people, this is how we can get more people to understand. I think that understanding the concept of limitations is something that the people of the Earth, when fully comprehended, will insist that things change.

    The example you used was good. The outcome of 66 billion was possible if we had the water to grow the rice,…but we don’t. I believe that water is the limiting factor. If you look at water per person to survive and account for the water to grow plants to sustain the environment (e.g. process CO2 to O2, process waste back to productive food and water, and for the birds, fish, and other fauna as well as the flora that provides drugs, and other useful products), and that for agriculture, we are way short of the 66 billion.

    Most people don’t think of all these ecosystem services. In fact there are movements to establish a replacement for the failing political economic system with one that is based on these ecosystem services that has more relevance to our well being and sustainasbility.

    Thanks for your blog, and I am glad that I have been an influnce.

    Sincerely,

    Hal

    • lenrosen4

      Hi Hal, Freshwater and climate are the two most significant inhibitors to a scenario or outcome similar to the theoretical one I described. But interestingly I came across an announcement about new hybrid rice developed in China that increases yield rates by a factor of between 4 and 6. I’ve written about this in the weekly headlines posted today.

  • FreedomDanK

    From the article : “….. we need to find others to provide us with guidance to achieve our common planetary goal. ” Why “others” ? Are we so stupid to realize that human numbers have to STOP growing, especially in Africa, and other poor countries – for THEIR SAKE,,and for the sake of saving the biosphere from suffocating in pollution ! Also, WHY we are not talking about OTHER forms of life without which our life would be completely intolerable and horrible . Over-consumption and Overpopulation are the TWO monsters eating up the Earth’s biosphere. So, we have to STOP both of them. Dan Kustudich

  • FreedomDanK

    Hal Millegan said: ” The example you used was good. The outcome of 66 billion was possible if we had the water to grow the rice,…but we don’t. ” The example was NOT good !! Would you really want to live like ants in an ant hill. with no room for walking through forest , or swim in an unpolluted lake ?? Only an idiot would like to live under that kind of overcrowded , polluted and sick society . FreedomDanK

  • lenrosen4

    Hi FreedomDanK,

    The others I described in my article are the non-political actors and leaders of this planet, alternatives to those who blindly take us closer to the cliff edge of overpopulation and global warming. Short of drastic remedies how do we deal with our population bomb? One can think of all kinds of dark scenarios, dictated policies that lower birthrates, forced sterilization, etc., anathema to most of us living in democratic societies. And as for the rest of the biology on our planet, we have taken from them any say in their future other than the right to survive us after we go extinct.

    For me a new generation of humans needs to lead in altering the future. They need to throw the bums out who cannot come up with policies and strategies to mitigate behaviors so that we who have set the planet on an unbalanced new course, can restore it to sustainability.