When Did We Stop Worrying About Population Growth?

In the environmental debates of the 1970s, one common name hurled at environmentalists was to call them “neo-Malthusians.”   This dismissive insult was meant to imply that the concern for environmental issues was nothing more than the contemporary application of the failed analysis of Thomas Malthus (1766-1834).  Malthus was a classical economist in the tradition of Adam Smith and David Ricardo.  He argued that human population naturally grows faster than the growth of food production, leading to what came to be known as Malthusian population controls – disease, famine, and war.  For Malthus, the desirable alternative was restraint on reproduction.

Many environmentalists in the 1960s and 1970s were concerned about how the rapid population growth in the post-World War II era was straining human ability to produce for itself.  Nature imposed limits.  When it was published in 1968, Paul and Anne Ehrlich’s The Population Bomb predicted global famine due to rapid population growth.  Much before this famous book, William Vogt’s 1948 Road to Survival warned that rapid population growth would make us feel “scarcity’s damp breath.”

Vogt, the Ehrlich’s, and others like Donella Meadows (one of the co-authors of The Limits to Growth) were labeled neo-Malthusians.  Their critics now crow that food supply has kept up with rapid population growth since the 1970s.  We did not see widespread famine in the 1980s and when famines did occur it was typically due to civil war and other forms of violence.  Certainly, inadequate nutrition remains a problem in many parts of the world, but it is not because we are unable to produce enough food to feed everyone fully.  Indeed many more people on the planet today are overfed than ever before.  Malnutrition is a matter of income inequality, not food production capacity as was thought by many environmentalists.

So, you might say, the critics were right.  Vogt, Ehrlich, Meadows, et al. were scare mongers.  Human ingenuity triumphed and population growth is not a concern.  I think that is the wrong lesson to draw from this story.  While the world’s population has more than doubled since The Population Bomb was published in 1968 without a global famine or pestilence, that does not mean we can remain complacent about the implications of continued global population growth.

Year World Population Yearly
Pop %
2017 7,515,284,153 1.11 % 82,620,878 58 4,110,778,369 55 %
2016 7,432,663,275 1.13 % 83,191,176 57 4,034,193,153 54 %
2015 7,349,472,099 1.15 % 83,686,153 57 3,957,285,013 54 %
2014 7,265,785,946 1.17 % 84,070,807 56 3,880,128,255 53 %
2013 7,181,715,139 1.19 % 84,214,686 55 3,802,824,481 53 %
2012 7,097,500,453 1.2 % 84,073,401 55 3,725,502,442 52 %
2011 7,013,427,052 1.21 % 83,702,009 54 3,648,252,270 52 %
2010 6,929,725,043 1.22 % 83,245,522 53 3,571,272,167 52 %
2009 6,846,479,521 1.22 % 82,746,642 53 3,494,944,744 51 %
2008 6,763,732,879 1.23 % 82,125,559 52 3,419,420,251 51 %
2007 6,681,607,320 1.23 % 81,387,073 51 3,344,752,515 50 %

Source: http://www.worldometers.info/world-population/world-population-by-year/

The world’s population is estimated now to be over 7.5 billion people.  And the human population continues to grow by over 80 million people a year.  To understand that figure, imagine a new United States added to humanity every four years.  Part of the complacency about population growth is due to the fact that most estimates now suggest that we are adding a million or two fewer people to the size of humanity than we were when growth peaked a few years ago.  But still, there are over 80 million more humans each and every year.  This should be a source of concern and a matter for public policy in this country.

But if we can feed everyone adequately on the planet (hence the neo-Malthusians were wrong), why is a growing population a problem?   First, we need to acknowledge why we are able to feed everyone with modern agriculture.  This is due to the simple fact that we have remade global agriculture in the image of U.S. and European industrial agriculture.  And this has been done because of the miracle of fossil fuels — petroleum and natural gas — which are at the root of every technology that allows food production to keep up with population growth.  Monoculture, synthetic fertilizers, irrigation, mechanization, and chemical pest management are all built on a foundation of increasing use of fossil fuel inputs to produce more food per acre of land and per hour of labor.  Essentially, we are supplementing solar energy captured by plants through photosynthesis with increasing quantities of fossil fuels. Thought about in another way, we would never be able to feed everyone on the planet using organic production methods.  So what’s the problem with 80 million more humans every year?

The problem is that we are straining to the breaking point a host of planetary systems upon which human life depends.  Humans have disrupted climate systems, dramatically increased the rate of extinction of other species, and fundamentally changed important biogeochemical cycles.  We have all heard about climate change due to disruption of the carbon cycle, but some scientists believe we have changed the nitrogen and phosphorous cycles even more dramatically, particularly due to the industrialized agriculture that has held off mass starvation.  The challenge is that in most of these areas, the messages that we get about our disruption of nature (feedbacks) are delayed or masked before we notice our effects.  The time between our emissions of carbon dioxide and changes in global climate systems is measured in years and decades.  Similar delays are seen in the impending crisis in extinction of species due to more humans on the planet. We are literally crowding out a host of plants and animals as more and more people take up more and more space to support our increasingly affluent lives.

Rising population numbers have political and social effects as well.  The most obvious example is the growing global humanitarian crisis due to migration.  As more people are unable to support themselves where human numbers have exceeded the carrying capacity of the landscape they try to move where life is better.  You and I would also.  In a very real sense, the growing migration issue around the planet suggests that the neo-Malthusians were right all along.  Whether it be Central Americans trying to reach the U.S. or North Africans seeking better lives in the E.U., migration pressures are tightly coupled with population growth.

If we are truly concerned about the wellbeing of the planet and of human society, we should return to engagement on the issue of population growth.  It is not an easy challenge to deal with; yet it will be impossible to address the issue if we continue to pretend that the problem has gone away.

Mark W. Anderson

About Mark W. Anderson

I am proud to be a Mainer, born in Caribou and schooled at Brewer High School, Bowdoin College, and the University of Maine. I am grateful for a 35 year career at UMaine, the last decade in the School of Economics.