Paul Ehrlich on Overpopulation
by Bill Chameides | February 3rd, 2009
posted by Erica Rowell (Editor)
Paul Ehrlich, professor at Stanford University and fellow member of the National Academy of Sciences’ Section 63 on Environmental Sciences and Ecology, spoke at Duke last night. His message on overpopulation has evolved to include consumption.
In 1968, Paul Ehrlich’s The Population Bomb predicted society’s imminent doom. Yesterday, speaking at Duke, he painted a picture for humanity that is less doomed but still quite sobering.
Except for maybe a Nobel, Paul Ehrlich, the Bing Professor of Population Studies at Stanford University, has won just about every award possible, from the MacArthur “Genius” Award to the Volvo Environmental Prize.* He is a tall stately man with a deep booming voice and a droll sense of humor.
In his extemporaneous speech last night, part of this year’s Provost’s Lecture Series at Duke, he liberally sprinkled in anecdotes and non sequiturs. My favorite was his reference to the work of Joshua Lederberg and E. L. Tatum, the team who “discovered” sex in bacteria. “The bacteria, said Ehrlich, “were ever so thankful.”
Ehrlich’s The Population Bomb made him a household name back in the late 1960s and early 1970s. In it, he characterized the rise in human populations as a runaway train that would lead to major catastrophes within a decade or two, as humanity’s needs outstripped available resources. Clearly Ehrlich’s doomsday predictions did not come to pass (at least not yet), and he has been roundly criticized by some (see here and here).
Probably his best-known debacle was his infamous wager with Julian Simon, the University of Maryland business professor who held opposing ideas on population. In 1980 Ehrlich (along with other colleagues, including President Obama’s soon-to-be science adviser John Holdren) bet Simon that the price of five commodities would go up over the ensuing 10 years. Ehrlich lost, and reportedly ended up having to pay Simon $567.07. While most have interpreted the bet’s outcome as a repudiation of Ehrlich’s thesis, Ehrlich claims otherwise.
The Missing Factors of Technology, Industrialization, and Educated Women
It is hard to debate the fact that, in his 1968 book, Ehrlich underestimated the ability of technological advances to keep ahead or even abreast of the burgeoning demand for resources driven by population growth and increasing affluence. I think he also didn’t adequately account for the fact that populations tend to stabilize as societies become more urban and industrial and women become more educated – this is the so-called demographic shift. In fact demographers now predict that because of this demographic shift, the world’s human population will stabilize sometime this century at perhaps 9 billion (see here and here). That’s a whole lot of people, no question, but at least it appears to be bounded.
But while Ehrlich may have gotten his timing wrong, his fundamental message that as a species we are on a collision course with the Earth’s limited ability to support us may be correct. Indeed Ehrlich’s talk at Duke yesterday evening, while perhaps somewhat more subdued than his speeches from earlier decades, was an impassioned plea to consider the course we are on.
A Look at Population in Terms of Numbers and Consumption
A subtle but important evolution in his framing of the question of population is the emphasis on consumption as well as numbers. By Ehrlich’s reckoning, America is the world’s most “overpoplulated” country. While only the third most populous, we use far more resources than any other country, and thus, in terms of impact, we have the largest footprint.
In contrast to years ago when his main issue was population control, last night Ehrlich cited four things that cause him the most worry about the future:
- Climate change: Ehrlich believes that the most serious consequence of global warming will be an undermining of agriculture and the collapse of our food supply;
- Earth toxicification: The hundreds of thousands of new chemicals we have added to the environment (e.g., endocrine disruptors) may be a time bomb waiting to decimate us;
- Emerging diseases: Overcrowding of people and animals is a dangerous recipe for a new pandemic;
- Nuclear weapons: Despite the end of the Cold War some 20 years ago, nuclear weapons remain “on hair trigger” alert in the both the United States and the independent states of the former Soviet Union; an accidental nuclear exchange could lead to “nuclear winter” and a collapse of the food supply.
Ehrlich, who spoke for a little over an hour, held our attention throughout. A small group of us then went to dinner to muse about science and politics. We got him to relate wonderful stories about his various world travels including his experience as a 19 year-old college student working with the Inuit. People may still call him a doomsayer, but he’s not the fire-and-brimstone type. He’s gregarious and easy going with a twinkle in his eye and a smile on his face.
While Ehrlich may have taken some lumps in sounding the alarm about humanity and the environment, he remains convinced of his message. And when all is said and done, I find it hard to dismiss his thesis that our society is in danger of outstripping the Earth’s ability to support it. Even at “just” 6.7 billion people, we are unable to find adequate resources for all – witness the close to a billion or so malnourished among us. Now imagine a world of 9 plus billion people. Maybe the Ehrlichs of the world have something to tell us.
*In fact a different Paul Ehrlich won the 1908 Nobel Prize in Physiology.filed under: climate change, faculty
and: disease, Duke University, John Holdren, Julian Simon, nuclear weapons, Paul Ehrlich, population, Stanford University, The Population Bomb