New York Times
December 8, 1998
Will Humans Overwhelm the Earth? The Debate Goes on
By MALCOLM W. BROWNE
PHILADELPHIA -- Two hundred years ago the Rev. Thomas Robert Malthus,
an English economist and mathematician, anonymously published an essay
predicting that the world's burgeoning humanpopulation would overwhelm
the earth's capacity to feed it.
Malthus' gloomy forecast, called "An Essay on the Principle of
Population As it Affects the Future Improvement of Society," was
condemned by Karl Marx, Friedrich Engels and many other theorists, and
it was still striking sparks last week at a meeting in Philadelphia of
the American Anthropological Society. Despite continuing controversy,
it was clear that Malthus' conjectures are far from dead.
Among the scores of special conferences organized for the 5,000
participating anthropologists, many touched directly or indirectly on
the dilemma suggested by Malthus: Although global food supplies
increase arithmetically, the population increases geometrically -- a
vastly faster rate.
The consequence, Malthus believed, was that poverty, and the misery it
imposes, will inevitably increase unless the increase in population is
curbed.
This contention has prompted endless debate. Malthus' critics have
argued that man's ingenuity will always keep pace with population
growth by finding improved ways to produce food. They cite the success
of the "Green Revolution" launched in the 1950s and 1960s by Dr. Norman
Borlaug and his associates in developing high-yield strains of rice and
wheat.
But the scientific descendants of Malthus argue that feeding the
world's masses is only part of the problem. Just as dangerous, they
contend, is the omnivorous consumption of nonrenewable resources, the
irreversible destruction of habitats and species, the fouling of the
air and seas and consequent changes in climate, and many other effects
of a growing human horde.
One of the symposiums held at last week's meeting was regarded as so
contentious that a similar conference was banned from the 1994 meeting
of the American Association for the Advancement of Science, on the
grounds -- said its organizer, Dr. Warren Hern, a Colorado physician
and epidemiologist -- that "you may not ask that question."
The question, posed as the title of the symposium, was this: "Is the
Human Species a Cancer on the Planet?"
Hern, the director of an abortion clinic in Boulder, Colo., noticed
nearly a decade ago that aerial and satellite views of urban centers
taken over a period of years bore a striking similarity to images of
cancerous tissue -- particularly melanoma -- invading the healthy
surrounding tissue.
In his presentation last week, Hern argued that in many parts of the
world the increase in human numbers is rapid and uncontrolled, that it
invades and destroys habitats, and that by killing off many species it
reduces the differentiation of nature. All of these features are
characteristic of cancerous tumors, he said.
This assessment was applauded by another member of the panel, Dr. Lynn
Margulis of the University of Massachusetts in Boston, who is the
co-author of another highly debated theory, the Gaia Hypothesis.
The hypothesis, the brainchild of an English theorist, Dr. James
Lovelock and Dr. Margulis, who is a microbiologist, is that the earth
deploys feedback mechanisms to maintain an environment hospitable to
life. In this it resembles a gigantic living organism, proponents of
the Gaia idea believe.
Life on earth has survived many crises, including mass extinctions
caused by the impacts of asteroids and comets, Dr. Margulis said, and
life will continue despite the threats created by humanity -- but with
reduced diversity.
She agreed with the notion that the human race is a kind of
self-destructive cancer.
"For millions of years," she said, "the earth got along without human
beings, and it will do so again. The only question is the nature of the
human demise that has already begun."
Dr. Margulis quoted a line from the German philosopher Friedrich
Nietzsche: "The earth is a beautiful place, but it has a pox called
man."
A different but complementary perspective was offered by Dr. Compton
Tucker, a physical scientist at the National Aeronautics and Space
Administration's Goddard Space Center. Tucker is an analyst of images
of the earth made by Landsat and other orbiting spacecraft. In
particular, he keeps track of deforestation and other anthropogenic
changes in the global habitat.
"In many regions, we've seen astonishingly rapid change since 1975," he
said. "Vast tracts of both rain forest and dry tropical forest have
disappeared in the Amazon Basin as human communities expand and clear
the land for cattle ranching. This has led to a monoculture dominated
by cattle breeding, with losses of immense numbers of the species
deprived of forest habitat."
Several speakers cited U.N. statistics indicating that population
growth rates in underdeveloped countries averaged only 1.77 percent per
year between 1990 and 1995. The expectation for that period had been
for a growth rate of 1.88 percent.
But since 1930, when the world population was about 2 billion, the
population has nearly tripled, and each doubling of the population has
occurred in a much shorter time than the previous doubling period. The
U.N. report projected that the world population could reach 9.4 billion
by 2050.
Demographers say that the population increase has leveled off in China,
where the government limits family size, and that the rate of
population increase has declined in Bangladesh and other populous
countries.
But recent U.N. statistics identified 28 countries -- 20 of them in
Africa -- where fertility rates increased during the past decade. Among
the countries was the United States, which has the third-largest
population after China and India, and where the fertility rate
increased from 1.9 percent to 2.1 percent, largely because of Hispanic
immigration.
All the speakers at the symposium had expected vigorous criticism from
the audience of anthropologists, but were surprised to encounter few
strongly negative comments.
"Arguments over the accuracy of Malthus' views, future population
trends and the earth's carrying capacity are never-ending and never
resolved," one speaker said. "Many people prefer to just forget about
the big questions involved, and get on with their lives."
Population pressure is partly a question of perception, said Dr.
Bernice Kaplan, an anthropologist at Wayne State University.
"I ask my students how they feel about being increasingly crowded by
the growing population, and they reply, 'We're not crowded,"' Dr.
Kaplan said.
"That attitude results from being young and not having experienced the
changes old people have seen during their lives. Whatever environment
you're born into is the one that seems normal.
"You don't seem to realize the problems created by population pressure
until you get old," she said, "and then nobody listens to you. We are a
species that doesn't respond to threats until it's too late."
-- end of forwarded article --
