Lately I’ve been debating a fellow online about the topic of overpopulation. He argues that world is overpopulated and we need to sterilize people to solve the problem. I argue that it’s not and we don’t. While the facts appear to be on my side, my opponent keeps pulling out sources which he claims are on his side. Most of his sources in are either anonymous internet posts or badly out-of-date or both. Nonetheless there’s no doubt that there have been serious people with serious credentials who have insisted that the world will soon run out of food or space or both. For example, in his 1968 book The Population Bomb, Paul Ehrlich wrote:
The battle to feed all of humanity is over. In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.
He followed that up in a 1970 interview with:
The death rate will increase until at least 100-200 million people per year will be starving to death during the next ten years.
In 1997, Lester Brown said, “Food scarcity will be the defining issue of the new era now unfolding, much as ideological conflict was the defining issue of the historical era that recently ended.” This was a follow-up to what he said in 1994: “The world’s farmers can no longer be counted on to feed the projected additions to our numbers.” And in 1981: “The period of global food security is over.”
As one born in the 80’s and growing up in the 90’s, the established fact of overpopulation was a steady drumbeat throughout by my schooling. Almost every science and social studies textbook included some mention of the fact that earth had too many people and we would soon run out of food and oil and other vital stuff. Yet, oddly enough, time went on and none of those things happened. Hundreds of millions of people did not starve to death during the 1970’s and 1980’s. There were not at least 100-200 million people per year starving to death during that time. Food scarcity is not the defining issue of our times. The world’s farmers have been able to feed the projected additions to our numbers. Indeed, the biggest health problem in the USA and a growing number of other nations is obesity, which implies that we have a lot more food than we used to. While some experts predicted dramatic increases in world poverty as resources ran out, we have instead seen dramatic decreases, according to this paper. So, in short, all the experts who have predicted imminent starvation and poverty due to overpopulation have been dead wrong.
Why were they so wrong? Many reasons. They didn’t take into account new technologies that would drastically improve agricultural yields. They didn’t take into account the fall of communism and the benefits that would accrue from the spread of economic freedom. They didn’t take into account virtually any of the things that they should have taken into account. But most of all, they didn’t take into account the fact that projections are only projections, and they can be wrong. It’s possible to predict every eclipse that will occur in the next thousand years, but it’s not possible to predict what the human race will do over the next thousand years, or even over the next year. No one a year ago was predicting the Arab Spring or any of the other major events in human affairs that shook the world in 2011.
So, in sum, overpopulation gives us a cautionary tale. Scientists can make predictions and projections, but they should always be taken with a grain of salt.