Exponential Population Growth and Sustainability

We all inhabit Planet Earth – a space defined by boundaries. According to the studies conducted by NEF (New Economic Foundation) it currently takes the biosphere about 18 months to produce what humanity consumes in only 12 months. This tipping point happened sometimes in 1960s.


If every nation in the planet consumed the same amount of natural resource as the US does, we would need between 5 -6 planet earths, to satisfy everybody’s needs.

The above data is from 2007. I was comparing this data to other sources, which vary for – / + 0.5. Looking at 2012 data, India increased from 0.4 to 0.8, China is up to 1.2 and Brazil to 1.9. The largest consumers of natural resources, not on this chart are the United Arab Emirates.


Source: http://esa.un.org/wpp/

Using 2012 data, China and India represent 2.6 billion people – rougly 38% of the world population – and growing.

One of the key factors related to global demand of natural resources is increasing number of population. However, we cannot neglect country’s purchasing power – their market position, access to natural resources and their level of development. For example – global oil consumption is  89 million barrels a day. United States consume 20 million barrels a day (22% of the global use) while they represent a fraction – only 4.5% of the total world population.  China currently uses 7m/b/day and has 1.35 billion people, with increasing needs and demands.

Global population growth represents exponential growth (a chart pattern that is often called a “hockey stick”).


For the last few months I’ve been working and living in Mexico and would like to demonstrate exponential growth of Mexico City. The city has between 20 and 22 million people ( 2012). In 1900, only 113 years back, the number was 0.5 million.

How does steady growth turn into exponential growth?

Let’s apply arithmetic, which I learned from Dr. Albert A. Bartlett. I have great respect for his wisdom, especially for the message he was trying to convey: “The greatest shortcoming of the Human Race is our Inability to Understand the Exponential Function.”

What is exponential function?

Exponential function is a mathematical function, used to describe the size of anything that is growing steadily, for example – 5% per year.

I came to realize how this problem affects numerous critical areas we’re facing at the moment, one of them being population growth. The case I have chosen demonstrates the importance of understanding unsustainable exponential growth and can be applied in others area; for example GDP – promotion of 5% steady growth of GDP, which is constantly brought forward by politicians as a solution to our current economic crisis.

Why it cannot work?

We are talking about a situation where the time that is required for the growing quantity to increase by a fixed fraction is constant. (e.g. 5% per year – 5% is a fixed fraction, 1 year is a fixed length of time). If it takes a fixed length of time to grow 5%, than it follows, that it takes a longer fixed length of time to grow by 100%. This longer time is called the doubling time.

a)      To calculate doubling time we need to apply a simple formula (using example of 5% annual growth)

Formula for Exponential GrowthCan we really achieve 10% growth in 14 years, 20% in 28 years and 40% and 42 years time?  Having limited amount of resources, lagging technology,  continuous investment in dwindling fossil fuel extraction and increasing CO2 emission? I think it’s about time to redefine growth!

b)      Let’s apply the calculation for population growth in Mexico City.

Based on National Statistical Data, the number of population in 1900 was approximately 0.5 million, 4.5 million in 1960 and 9 million in 1980, following the average growth of 3.5% yearly until 2000 when it dropped to 2%.


No. of population according to our calculation

Doubling time

Numbers according to Nat. Statistics



Recorded average 3.5% growth between 1900 and 2000

70/3.5 à 20

Every 20 years the number of people doubles











The growth rate fell to 2% in 2000s, it takes now 35y for the population to double






20 -22.000.000




The results of calculation match with the actual data. There is minor deviation due to the average of 3.5%  between 1900 and 2000, which is acceptable and accurate enough to confirm the validity of results. Using other important indicators, which affect life on earth we notice similar patterns.

Hockey Stick

Graphs above follow the same “hockey stick” pattern, typical for unsustainable exponential growth (Melting of Arctic Sea Ice, Global Land and Ocean Temperature, Number of Weather related Disasters, Global Ocean Acidification, Human Population Growth,  CO2, N2O and CH4 Emission, Oil Extraction).


We started off with a steady growth, lasting for 80 years, which tipped over into unsustainable exponential growth after 1980s. Mexico City has begun sprawling out and up the surrounding hills, once a home of rich biodiversity, covered with trees, to protect from landslides, today covered by concrete houses.

The natural conditions and the infrastructural foundations of Mexico City was not built to accommodate 32 million people.  What I’m currently able to see around me is poor infrastructure, inefficient transport system, pollution, poor quality of water, high level of food dependency, dependency on fossil fuels and increased social inequality. In addition to that, the city was built on plate tectonics, on soft unconsolidated sediments that fill a former Lake Texcoco, surrounded by volcanos. It has a history of earthquakes, the latest and most damaging one was in 1984 with the magnitude of 8.1 on Richter Scale. In 1980s, there were only 9 million people.

You may say it’s an extreme example, and yes, I agree – it is. It just happens to be that I’m currently working and living in this city, hence it’s real to my eyes and I have a direct overview and experience of how it functions on daily basis.

Such extreme examples indicate our extreme inability to connect the dots and think & live sustainably. This example shows we don’t think carefully enough about the future, we don’t protect the environment and the generations yet to come and we are not ensuring them access to clean water, healthy food and breathable air.

Such is the case with Mexico City. Despite all, Mexicans remain one of the happiest, most optimistic and good hearted people I have ever met and I’m fully grateful for the experience. I only wish they would be encouraged to think about the bigger picture, not only about the American dream, that exists only in dreams. Most of the people living in this city struggle to earn their daily bread, to make it through the day, week or month. Current system doesn’t do much to support and/ or encourage a more sustainable way of thinking and living. My comments are made based on general observation and conversation I had with variety of people including students and faculty from privately owned and state Universities.

MexicoCity,22mpeople1,485squarekmMexico City

We can apply exponential growth to other areas. Graphs above show a similar pattern in many critical areas we’re presented with at the moment. They are affecting the whole globe. Knowing how exponential growth works, we can realize that current understanding of steady GDP growth is not only impossible; promoting such growth by policy makers and certain experts is deceiving and destructive in a long term. It simply can not be sustained.  As physical beings we inhabit Planet Earth, and as such, our space is defined by physical boundaries.

Next: Deforestation (tbc)

Introduction of a new Journey – Education and SustainAbility

I was inspired to share my observation and understanding of Sustainability after seeing a Facebook post on my friend’s wall with a title “Human Induced Climate Change is False”. I followed the link with a video and listened carefully, with an open mind to what the person was about to share.

From where I came to be and from what I came to understand about this topic, I noticed this person using the word complexity, without grasping its meaning. He was talking about economic, social and environmental problems as being unrelated to implications of Climate Change. He spoke of unnecessary investments and efforts to create a more sustainable ways of living and doing business.

Such presentations can easily misguide many, especially newcomers who are still forming an understanding about Climate Change and Sustainability; even more so during times when critical thinking is in decline. My understanding is not complete; but I’m confident to say it is more complete when compared to much of what I hear, read and see in connection to Sustainability.  However, I leave you with a “ResponseAbility” not to take what you see and read for granted, but to form “your” own opinion, while keeping your heart and mind open.

Inquiry into Sustainability   Author: Brigi

The topic is broad, hence I have decided to divide the areas of Sustainability affecting the health of the biosphere our lives depend upon into several parts. In my next post I will present part one – “Population Growth”. The parts I’m about to share are interconnected and interdependent – hence I will emphasise the focus of the one I have chosen, while drawing connection between all of them.

My journey of intellectual and a more holistic understanding of Sustainability started in September 2011 at Schumacher College in Devon, when I signed up for a full time Master’s in Economics for Transition – a program specialized in Environmental Sustainability, Low Carbon Economy and Holistic Education.

I have deeply delved in the area of sustainability for the past 2 years and have tried to see it from as many perspectives as possible – as a human being – biologist, economist, banker, investor, psychologist, agriculturist, anthropologist, educator, ecologist, mathematician… and most importantly, as part of nature.

 Ecocentric Egocentric                  Author: Brigi

My intention to learn and know more is being driven by the care for all of life that surrounds us. To address the issues we are facing I wish to shed light on the process of what is happening. By my humble opinion, it is the process that matters most – means that lead to a never ending end.

Next: Part 1: “Population Growth in Relation to Sustainability

Iterration no.2

Second Screening, Kevicc High School, Totnes, May 2012

Iteration process  2

The second screening took place at Areal Cinema Theater, at Kevicc High School in Totnes. The event organization was supported by Earth Inheritors, a group of young inspiring students from Kevicc High School.

Approximately 40 people attended the screening, ranging from college students to adults in their late sixties. The event was introduced by doctor Robert Cook from University of Plymouth. Dr Cook worked on his research in Ladakh, together with Helena Norberg Hodge and later on for SECMOL (The Students’ Educational and Cultural Movement of Ladakh). Dr Cook was looking at the cultural changes in connection to sustainability and education.

More on SECMOL: http://www.secmol.org

After watching the documentary we invited participants to express their experience through art and drawing. This time was used for self reflection, before engaging in group discussion.

Following issues were raised during our discussion:

  • Importance of localization
  • Negative impact of standardized educational system
  • Negative impacts of excessive, unsustainable form of globalization
  • Importance of knowing one’s own cultural identity and background


  • How to identify a good teacher?
  • What is the purpose of education?
  • Are we educating people for jobs or to help them recognizing who they are?
  • How to educate for the place you live in – educating for the ecosystem?
  • What are the signs of indoctrination within educational system?
  • How to marry traditional and modern ways of thinking – how to marry traditional culture and technology?
  • What is the appropriate size of the school and classrooms?


  • Importance of educators to develop a “midwife”  attitude.
  • Learning from successful, non conventional examples, such as SECMOL (The Students’ Educational and Cultural Movement of Ladakh)
  • Recognition of local characteristics, learning from the local environment
  • Educational system should first and foremost be the space of self discovery through freedom of expression, with individuals being supported on their journey.

The event was successful, very much appreciated by the participants and very insightful.

Schooling for Future is a documentary on education I’m working on. I will be adding the second part by the Mid October.






I have chosen to create “Schooling for Future” as a part of my final project on a postgraduate program I’m currently finishing. This project came out as a result of 6 successful screenings of documentary “Schooling the World” (directed by Carol Black) and discussions among participants, which were held after watching the film.

The work you are about to see is a first part of a documentary about purposeful education. The second part will be completed by the Mid October.

Through the process of my academic research I was aiming to find the connection between thoughts of radicals thinkers in the realm of purposeful education such as: Rabindranath Tagore, Maria Montesori, Krishnamurti, Ivan Illich, John Dewey, Bertrand Russell, Sir Ken Robinson, Alan Watts, Nikhil Goyal, Noam Chomsky, Paolo Freire, Gregory Cajete, Allan R. Wallance, Rudolf Steiner, Satish Kumar

and between the thoughts of participants who came to the screening of the documentary “Schooling the World”.

Main reason for choosing “Schooling the World” as a foundation for my research are the challenges that educational system represents for society today. Stories in this documentary point out to those challenges in a very clear, somehow provocative, but engaging way.

Challenges I am referring to:

– current educational system is not encouraging individuals to learn directly from our greatest teacher – the nature itself;
– current educational system is not encouraging creativity and freedom of expression;
– current educational system is not fully supporting individuals to discover and develop their own potentials;
– current educational system is becoming increasingly standardization across the world
– educational system is being used to support global economy, for the price of one’s own unique cultural identity and value system;
– current educational system is result driven and lacks the important recognition of process focused education.
These are few thoughts I was interested to look into and to find out how and if they were seen by some of the greatest thinkers as far as 100 years ago. I also wanted to find out what members of society think today.

I have also been asking myself a question, how to support those great noble thoughts to become more wide spread. I discovered that most of participants who engaged in discussion after the screenings share those same thoughts. Thoughts, which can lead towards creation of a more sustainable education and have a positive impact on society and life on Earth.

Hopefully I can make a humble contribution with the composition I am sharing with you here.

I am very grateful to Satish Kumar for his words of heartfelt wisdom, to dr. Robert Cook for sharing his experience in Ladakh and to everybody who joined this unique “Journey of Exploration through the Process of Education”.

Thank you for being the change you wish to see in this world!