Guest Blog: The World Population Hit 7 Billion

As the first guest blogger, allow me to introduce myself. I am a graduate student in the Sociology Department at the University of Washington. My area of focus is Demography, or more specifically defined, the statistical study of human population. In general, Demographers study issues related to fertility, mortality, migration and immigration. My specific area of focus for my dissertation research is educational inequalities, but I also spent a signficant amount of time studying fertility and contraceptive use in Indonesia and Southeast Asian Demography for a recent book chapter I co-wrote with my advisor.

As a student of Demography, naturally I get very excited when the results from the most recent US Census are published, or when an interesting situation in Japan leads to questions about life expectancy,  or even a recent finding that Mexican-American births are overtaking immigration numbers for the first time in history.

I was particularly intrigued waking up to a story on NPR on Halloween about how the human population reached 7 billion people and the implications of this number. The story also included a very interesting video on the world’s population and its growth over time using water dripping into and out of a tube. Showing the regions of the world by continent (with the exception of India, China and the rest of Asia) could be somewhat misleading. By grouping Southeast Asia with Japan, one might miss that Japan would probably have a very small amount of water dropping in from births and a the rate that it drops out from deaths would also be very slow due to a very high life expectancy.

Another neat website I came across while researching this subject is the BBC World App that allows you to enter your birthdate, country and gender so you can see where you fit in the human population. According to the app, I was the 4,579,633,137th person alive on Earth and the 79,245,691,742nd person to have lived since history began. The calculator also shows the number of births, deaths, immigrants and the average yearly growth per country and the life expectancy by gender. According to the calculator, I should live, on average 80.5 years, as a 29-year-old female living in the United States.  This information was taken from the 7 Billion and Me website developed by the UN. This website goes into more detail and tells you how many people have died since you were alive, the number of people born in different continents, the gender breakdown, and even the number of species that have become extinct since you were born, among other things. Very interesting (at least for a Demographer like me)! National Geographic also released an online and print series on the population reaching 7 billion people and the New York Times Blog created a visual capsule capturing our world at 7 billion people.

Population growth has always been somewhat of a popular topic among Demographers. In 1968, Paul Ehrlich wrote the book, “The Population Bomb” which stated that the world population would grow rapidly and even double between 1960 and 1999. While Ehrlich’s work is mostly dismissed by modern-day Demographers, his assumptions were not far-fetched given the time period. Family planning programs were not widely established in developing countries at the time, so women in countries with high fertility did not have access to modern birth control. For example, the Chinese One-Child Policy was not even established until 1978, so just looking at China during Ehrlich’s time would lead one to believe that the population was rapidly expanding. Also, advances in medical care and techniques, particularly for infants, has kept the mortality rates for many countries lower, so the need to have more children has diminished since the 1960s. For example, the total fertility rate (meaning the average number of children a woman will have if she survives through her entire reproductive period based on the rates of the period) from 1965-1970 was 4.45 children per woman for the world, and 5.37 children for less developed regions according to the UN Population Division 2010 projections. For the 2005-2010 time period, the numbers decrease to 2.52 for the world and 2.69 for the less developed regions. This shows a leveling out in the reproductive rates of the less developed countries with the more developed countries and that now less developed countries are also approaching replacement fertility, or when couples are only producing two children to replace themselves.

The most intriguing part about all of this is not that the human population has grown so rapidly over time, but rather how and where this growth is taking place. My advisors, who went to graduate school 30 + years ago, claim that much of what they focused on in their research was the rapidly growing human population, whereas I had to address issues with shrinking populations in Europe and Japan in a general exam question  a few years ago. Europe has fallen to below replacement level in 2005-2010, with a total fertility rate of only 1.53 children per woman, with Southern Europe at 1.43, Eastern Europe at 1.41 and Northern Europe at 1.83. Southeast Asian countries perhaps have the most remarkable decreases in fertility, with countries such as Thailand dropping from 6.13 children per woman in 1965-1970 to 1.63 in 2005-2010, Singapore dropping from 5.12 to 1.25 and Vietnam dropping the most remarkably from 7.33 to 1.89. East Asian rates are also very low. Japan has a rate of 1.32 children per woman, and Korea is at 1.29, down from 5.29 in 1965-1970.

According to the UN Population Division, mortality has also undergone a tremendous change since the 1960s. The life expectancy of the world was only 51.19 years in 1965-1970 and now it is 67.88. For Asia, the numbers raised from 46.36 to 68.98. That means, on average, people are living 20 years longer than they were 40 years ago. Japan, of course, has the highest life expectancy at 82.73 years.  The infant mortality rate has also significantly decreased over time. In 1965-1970, 94 out of every 1,000 infants died. In 2005-2010, only 46 out of 1,000 died. For less developed countries, the number decreased from 152 out of 1,000 in 1965-1970 to 80 out of 1,000 in 2005-2010. This indicates that the infant mortality rate was cut in half for the world, and for essentially all regions of the world as well. Most remarkably, for more developed regions, only 6 out of 1,000 infants die each year.  This indicates that for infant survival, a woman has to be less cautious of infant death than 40 years ago, and therefore can have fewer children to ensure greater survival of those children.

So the real question is, in a place like Vietnam or Korea who went from high fertility to low fertility, or a place like Japan, where live a very long time, who is going to take care of the elderly? If parents aren’t even replacing themselves, there will be multiple parents, aunts and uncles for each child. Who will pay for the pensions of these retirees as well? Some of this can be answered by immigration, but not all of it. France, which just saw its fertility rate drop below 2 for the first time in history, offers financial incentives to women who have more than two children. Will this work? Is a few thousand dollars worth the costs of the lifetime of another child, plus will having a third child impact a career? It may be too soon to tell, but since the worldwide trend seems to be to have fewer children, this may be too little, too late.

I think the big question on everyone’s mind is should we be concerned about this growth? If you ask me, the answer is a that it is not the growth we should be concerned about, but rather how we control poverty and take care of our rapidly aging populations with fewer and fewer young people in a given society.  Also, we’ve seen that the Earth can accommodate 7 billion people and probably many more than that, but how can we create a sustainable environment to continue to utilize our natural resources and not deplete the resources given to us? This could lead to a beautiful marriage between Demography and Environmental Science. Unfortunately, I do not have another 5 years to earn a second PhD, so hopefully future scholars will continue along the path to interdisciplinary scholarly research and establish the consequences of population growth on not just our society, but also our planet as a whole.


Sabrina Bonaparte is a PhD candidate in the Sociology Department at the University of Washington. Her main focus is demography and her current dissertation research is on the educational attainment of immigrants and ethnic minorities in the United States.