Science and Public Policy

Our man in science goes to Congress

(Page 2 of 2)

What happened is that babies stopped dying shortly after being born, as had been the case throughout the millennia for human beings. The global infant mortality rate dropped from a couple of hundred per thousand to below 50 per thousand today. The result is that human life expectancy has more than doubled from an average of only 30 years in 1900, rising to 46 years by 1950, and is now 66 years in the year 2001. That is a global figure. The World Health Organization thinks life expectancy will increase to 73 years on average by the year 2020. I would submit to you that this is truly evidence for the greatest improvement of the human condition in all of history.

What about future population trends? One still hears from activists that the world population will rise to 12 to 15 billion by 2050, or if they are being more cautious—and they have been lately—to that amount by the year 2100. But there is a lot of evidence to suggest that is very unlikely.

First let's look back at the predictions made in the 1970s. If famine were somehow miraculously avoided, Paul Ehrlich and Lester Brown both predicted that world population in 2000 would be seven billion people. In fact, as I have already mentioned and as we all know, world population is only a bit over six billion. Keep in mind that there is no predictive theory of demography. However, everyone acknowledges that the rate of world population growth is rapidly decelerating now.

The United Nations' World Population Prospects, the 2000 revision, has dropped its medium world population projections for 2025 to 7.8 billion people. Only four years earlier in 1996, it had projected a world population in 2025 of 8.4 billion. In other words, 600 million people disappeared in only four years. They are not going to be with us. This decline in the growth rate is going much faster than many people think. According to many other demographers, this impressive drop indicates that the world population trends are likely to track the UN's low variant trend, in which world population will top out at around 7.5 billion or so in 2040 and then begin to drop. In fact, if the low variant trend is followed out, world population in 2100 would be back to six billion. Even Nature magazine in July 2001 published work that concludes that it is exceedingly unlikely that world population will ever exceed ten billion people.

What has happened, of course, is that women are having fewer children than they did, dropping from nearly six children per woman in the 1960s to around 2.6 today, and that rate continues to fall. The replacement rate is 2.1 children per woman, and all developed countries have already fallen below that, including the United States.

Of course, the reason that Ehrlich and others predicted demographic disaster was their devotion to Malthusian theory. I have always been impressed by the fact that ecologists and biologists, for some reason, seized upon very early economic theory to inform their initial theories in the 19th century, but refuse to listen to economists nowadays. In any case, what confounded their predictions of doom is the advent of the Green Revolution, which was nurtured by Nobel Peace Prize winner Norman Borlaug and his colleagues. The Green Revolution has been summed up as "making two blades of grass grow where only one could grow before." Indeed, food production has more than doubled since the 1960s.

By the way, Ehrlich was a great skeptic of the Green Revolution. He was quoted in Life magazine saying: "It will soon turn brown." Since 1970 the amount of food grown per person globally has increased 26 percent, even as the world population nearly doubled. The International Food Policy Research Institute recently reported: "World market prices for wheat, maize, and rice—adjusted for inflation—are the lowest they have been in the past century." In fact, they are all 90 percent lower than they were in 1850. People are now paying 10 percent of what people paid in 1850 for their food, the basics of life. According to the World Bank, food production did increase 60 percent between 1980 and 1997. We can conclude that food is cheaper and more abundant than it has ever been in all of human history.

And more good news: The amount of land devoted to growing crops has barely increased over the past 30 years, meaning millions of square miles of land have been spared for nature with concomitant benefits for biodiversity protection. So, Malthus, Ehrlich, Brown, and many other ecologists were spectacularly wrong. More food does not mean more people. In fact, it turns out, unfortunately for me, that more food means more fat old people.

Let me close with a brief tour of past predictions about species extinctions. Again the predictions by concerned scientists were way off the mark. In 1970, Dr. S. Dillon Ripley, secretary of the Smithsonian Institute, predicted that in 25 years, somewhere between 75 and 80 percent of all the species of living animals will be extinct. That is 75 and 80 percent of all species of living animals would be extinct by 1995. In 1975, Paul Ehrlich and his biologist wife, Anne Ehrlich, predicted that "since more than nine-tenths of the original tropical rainforests will be removed in most areas within the next 30 years or so, it is expected that half of the organisms in these areas will vanish with it." It's now 29 years later and nowhere near 90 percent of the rainforests have been cut.

In 1979, Oxford University biologist Norman Myers suggested in his book The Sinking Ark that 40,000 species per year were going extinct and that 1 million species would be gone by the year 2000. Myers suggested that the world could "lose one-quarter of all species by the year 2000." At a 1979 symposium at Brigham Young University, Thomas Lovejoy, who is now the president of The H. John Heinz III Center for Science, Economics, and the Environment announced that he had made "an estimate of extinctions that will take place between now and the end of the century. Attempting to be conservative wherever possible, I still came up with a reduction of global diversity between one-seventh and one-fifth." Lovejoy drew up the first projections of global extinction rates for the Global 2000 Report to the President in 1980. If Lovejoy had been right, between 15 and 20 percent of all species alive in 1980 would be extinct right now. No one believes that extinctions of this magnitude have occurred over the last three decades.

What did happen? Most species that were alive in 1970 are still around today. "Documented animal extinctions peaked in the 1930s, and the number of extinctions has been declining since then," according to Stephen Edwards, an ecologist with the World Conservation Union, a leading international conservation organization whose members are non-governmental organizations, international agencies, and national conservation agencies. Edwards notes that a 1994 World Conservation Union report found known extinctions since 1600 encompassed 258 animal species, 368 insect species, and 384 vascular plants. Most of these species were "island endemics" like the Dodo. They are particularly vulnerable to habitat disruption, hunting, and competition from invading species. Since the establishment of an endangered species list only seven species have been declared extinct in the United States. Four are freshwater fish: the Tecopa pupfish (1982), the Amistad gambusia (1987), the Cisco longjaw (1983), the blue pike (1983); a freshwater clam, the Sampson's pearlymussel (1984), and two small birds, the dusky seaside sparrow (1990) and the Santa Barbara song sparrow (1983).

Let me say clearly from a personal perspective that species extinction is undesirable and should be avoided when reasonably possible. Extinction really is forever. But to put it in perspective, Science magazine just published an article called "Prospects for Biodiversity" by Martin Jenkins, who works for the United Nations Environment Programme-World Conservation Monitoring Center that bears on this topic. Jenkins points out that even if the dire projections of extinction rates being made by conservation advocates are correct they "will not, in themselves, threaten the survival of humans as a species." The Science article notes, "In truth, ecologists and conservationists have struggled to demonstrate the increased material benefits to humans of 'intact' wild systems over largely anthropogenic ones [like farms]....Where increased benefits of natural systems have been shown, they are usually marginal and local."

What are the lessons to be learned from this record of badly exaggerated predictions of environmental disaster? First, scientists, even well meaning ones, don't know as much as they think they do. They generally go wrong because they ignore or misunderstand how human beings interact with the natural world and with other people, that is, they are largely ignorant of economics. This ignorance constantly leads them astray because as biologists and ecologists, they tend to think that human beings are merely more clever herds of deer. When deer run out of their sustenance, they die. When human beings begin to run out, they turn their brains and their social institutions to producing more. Science can tell us what may be problems, but it can't tell us what to do about them. Solutions depend on a deep understanding of human values, politics, and economics. Scientists are no more qualified to pronounce on those topics than their non-scientific confreres and fellow citizens.

Policy makers must be very cautious about rushing to adopt policies to respond to alleged environmental crises. As physicist Edward Teller reminded us: "Highly speculative theories of worldwide destruction—even of the end of life on Earth—used as a call for a particular kind of political action serve neither the good reputation of science nor dispassionate political thought."

I hope that I have also made it clear that it is very important to hold people to account for their past predictive failures. Also, have patience, the scientific process and peer review will eventually point us to the truth. Finally, it should be clear that environmentalist advocates keep making the same mistake over and over: they constantly underestimate the power of technology and science, and underestimate the power of markets to solve emerging problems. Thank you for your attention and I would be happy to answer any questions.

For more details please see my articles "Running Out of Evidence: The environmental movement's collapsing case that we are running out of natural resources" published in November/December 1998 issue of The Philanthropy Roundtable. Also see my chapter "The Progress Explosion: Permanently Escaping the Malthusian Trap" from Earth Report 2000: Revisiting the True State of the Planet, (Free Press, 2000) a version of which was published in The National Interest.

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