The purpose of the following blog post is to introduce the reader to the concept of human population growth. In addition, the discussion also aims at presenting the different opinions regarding the effects that the exponentially increasing human population has on our global environment and on the quality of life in general.

To begin with, different demographic entities have different estimates as to the exact number of people on our planet, and more precisely as to whether or not we have already surpassed 7 billion. To name one, according to the United State’s Census Bureau, as of today, world human population amounts to 7,054,762,259. (2) For more detailed information, click here.

However, despite the different views on the exact number of humans inhabiting planet Earth, one thing remains for sure, and that is the fact that we have already surpassed our planet’s carrying capacity, or “the maximum population size of a species that a given environment can sustain” (3). To this effect, there are a number of causes to and consequences of human population growth. Some of the factors that have indeed facilitated it are more agricultural production, new technologies, better medical care and sanitation, etc. Similarly, some of the consequences are denser populations, more waste and pollution, global climate change, more resource extraction, etc. (3)

But is population growth indeed a serious problem for our planet? In general, there are two opposing views regarding the answer to this question – Cornucopian and Cassandra. “Under the Cornucopian view that many economists hold, population growth poses no problem if new resources can be found or created to replace depleted ones. In contrast, environmental scientists [which adhere to the so called Cassandra view] recognize that not all resources can be replaced. Once a species has gone instinct, for example, we cannot replicate its exact functions in an ecosystem or know what benefits it might have provided us” (3). According to the latter perspective, human population growth is indeed an extremely serious problem that may have disastrous consequences on life on planet Earth.

As far as I am concerned, I recognize that both sides have sensible arguments that justify their theories. Yet, I would tend to agree with the J. Withgott and S. Brennan who state that, “unless the availability and quality of all resources keeps pace forever with population growth, the average person in the future will have less space in which to live, less food to eat, and less material wealth than the average person does today.” (3)

On the issue of what impact human population growth has on our planet, biologist Paul Ehrlich from Stanford University is perhaps the most famous individual who shares the Cassandras’ view. In “The Population Bomb”, a best-selling book he published in 1968, Ehrlich “predicted that population growth would unleash famine and conflict that would consume civilization by the end of the 20th century” (3). Although his theory could not have possibly taken into account the Green Revolution’s effects on agricultural production and population growth, Paul Ehrlich has made significant scientific contributions by his famous IPAT model, which he designed together with John Holdern of Harvard University. “The IPAT model represents how our total impact (I) on the environment results from the interaction among population (P), affluence (A), and technology (T):

I = P x A x T (3)

To illustrate how the equation works, we can take as an example the USA, China and Bulgaria and examine their equations. To compare the first two countries, which are the two largest economies in the world as of today, we see that they may be said to have equal coefficients regarding their affluence value (A) and technology value (T). The citizens of both countries have at their disposal the advancements of high technology and also make use of large financial resources thanks to their very high GDP per capita. The difference in their two equations would stem from the population factor (P), which is way larger for China compared to the US due to the fact that it is the most populated country in our world with almost 1 and a half billion compared to the United States’ 350,000,000. However, both countries have extremely high total impact (I) coefficient as a result of the factors listed above. Bulgaria, in turn, with a population of about 7 million, of moderate income and more or less developed, but not strikingly advanced technology, would have a considerably smaller impact (I) coefficient compared to that of the United States and China.

In continuation to the discussion of what has contributed to human population growth and how countries have developed throughout the decades of the last two centuries, following is a very interesting TED talk by Hans Rosling, a Swedish Public Health professor.

From the video, we can make ourselves familiar with the perspective which the speaker shares on the issue of development, human population, and how one has influenced the other. I would be inclined to believe that the scientist belongs to the so called Cornucopian view, since he demonstrates how economic developments have helped increase life expectancy and stabilize world populations in some countries. One thing that I particularly liked about the talk was the professor’s suggestion to stop differentiating between the so called “Western world” and the “developing world”. I really liked the way he proved this point of his by explaining that there is no longer a dividing line between the developed and developing world, and how what we witness today represents some kind of convergence between the world’s countries. Also, I was really impressed by his implicitly stated idea that the best way to measure the progress of a country is to examine its child mortality/survival rates, rather than resorting to indices like the GDP per capita, let’s say. I find this exciting because it helps us prove that progress cannot necessarily be measured strictly in classical economic terms.

As a matter of fact, progress does not always bring with itself only favorable consequences. To give one example, below is a graph generated by the free application Gapminder. It demonstrates the positive relationship between GDP per capita, an index which in classic economics symbolizes ‘growth and development’, and CO2 emissions in Bulgaria starting from 1879 until today. The graph illustrates how, the richer the average Bulgarian is, the more he/she is inclined to produce/consume — actions, which inevitably increase CO2 emissions in the air.

The relationship becomes quite evident especially after the 1960s, a decade in which the then young Communist state begins to develop industrially in order to establish the necessary facilities needed for a functioning communist economy. As can be seen in the graph, this is also the period in which CO2 emissions begin increasing almost linearly as GDP per capita increases.

To conclude, there are many questions that arise from the current human population growth in the world, whose answers, however, are not necessarily so straightforward. The best we can do it address the issue seriously and try to take the necessary precaution measures until it is not too late.

References:

(1) “After Seven Billion.” New Geography. N.p., n.d. Web. 26 Nov. 2012. <http://www.newgeography.com/content/002625-after-seven-million>.

(2) “Current Population Clock.” U.S. & World Population Clocks. N.p., n.d. Web. 25 Nov. 2012. <http://www.census.gov/main/www/popclock.html>.

(3) Brennan, Scott R., and Jay Withgott. Environment: The Science behind the Stories. San Francisco: Pearson/Benjamin Cummings, 2005. Print.

(4) “Stanford Professor Paul Ehrlich to Deliver Nieuwland Lecture.” Notre Dame News. N.p., n.d. Web. 26 Nov. 2012. <http://newsinfo.nd.edu/news/8013-stanford-professor-paul-ehrlich-to-deliver-nieuwland-lecture/>.

(5) “Explore the World by Yourself.” Gapminder World. N.p., n.d. Web. 26 Nov. 2012. <http://www.gapminder.org/>.