Thoughts on Long−Term Energy Supplies: Scientists
and the Silent Lie
The world's population continues to grow. Shouldn't
The most sacred icon in the "religion" of the US economic scene is
steady growth of the gross national product, enterprises, sales, and
profits. Many people believe that such economic growth requires steady
population growth. Although physicists address the problems that result
from a ballooning population—such as energy shortages, congestion,
pollution, and dwindling resources—their solutions are starkly
deficient. Often, they fail to recognize that the solutions must involve
stopping population growth.
Physicists understand the arithmetic of steady, exponential growth.1
Yet they ignore its consequences, including the first law of sustainability:
"Population growth or growth in the rate of consumption of resources
cannot be [indefinitely] sustained."2 (See Ben Zuckerman's
letter to the editor, Physics Today, July 1992, page 14.) Sustainability
requires solutions that will be effective over time periods much longer
than a human lifespan. Indeed, Paul Weisz makes a case on page 47 of
this issue that many time−honored 20th−century energy sources,
such as petroleum, natural gas, and coal, have been reduced to the point
that their longevities are now expected to be of the order of a human
Physicists and energy
Among physicists, there is a growing recognition that we have a responsibility
to become more directly involved in the scientific aspects of problems
facing society. As an example, consider the April 2002 special issue
of Physics Today, which addressed specific energy problems. Let's focus
on two of the articles in that issue: Stephen Benka's introductory essay,
"The Energy Challenge" (page 38), and Ernest J. Moniz and Melanie A.
Kenderdine's lead article, "Meeting Energy Challenges: Technology and
Policy" (page 40). The titles alone convey a common commitment to society.
In his essay, Benka outlined the magnitude of the challenge by citing
projections from the US Department of Energy: Between 1999 and 2020,
the world's total annual energy consumption will rise 59% and the annual
carbon dioxide emissions will rise by 60%, while the world population
increases from 6.0 to 7.5 billion people. But here's the rub: Scientists
may call for solutions to meet the rising demands of population growth,
but as long as we postulate the continuation of that growth, the attendant
problems of energy consumption and increasing CO2 emissions
cannot have long−range solutions. The two articles in Physics
Today fail to identify stopping growth as a necessary condition for
the success of any proposed long−range solutions to the problems
caused by population growth.
Scientists have occasionally acknowledged that population growth is
the major cause of our problems. But I wonder whether their general
reticence stems from the fact that it is politically incorrect or unpopular
to argue for stabilization of population—at least in the US. Or
perhaps scientists are simply uncomfortable stepping outside their specialized
areas of expertise.
Unchecked population growth as a source of problems is not news. More
than 200 years ago, mathematician Robert Malthus (17661834) addressed
the issue in his famous essay.3 He understood that populations
had the biological potential for steady growth and that food production
did not. Today, energy production does not have the capability of steady
Nevertheless, we are all aware of nonscientists with academic credentials
who proclaim that our modern technology has proven Malthus wrong. The
most egregious of the high priests of endless growth was the late Julian
Simon, professor of economics and business administration at the University
of Illinois and later at the University of Maryland. In 1995, he wrote:
Technology exists now to produce in virtually inexhaustible
quantities just about all the products made by nature. . . . We have
in our hands now . . . the technology to feed, clothe and supply energy
to an ever−growing population for the next seven billion years.4
In the eyes of the general public, the silence of scientists on the
problems of population growth seems to validate the messages of the
politically appealing and influential Julian Simons of the world.
In addressing the problems, Benka noted that "most of the growth in
all three areas [energy consumption, CO2, and population]
will take place in rapidly developing parts of the world." It is expedient
to blame others, but because the US consumes so large a fraction of
the world's energy resources, we Americans are effectively the worst
offenders in those areas. Our population growth rate of more than 1%
per year is the highest of any industrial nation. The US can't preach
that other countries should limit their population growth unless we
are willing to set an example and do so first.
Benka later argued, "It seems certain that the world will continue
to rely heavily on hydrocarbon combustion for the foreseeable future.
. . . However we must develop alternative energy sources." To be fair,
Benka was not sanguine about the problem of energy shortages. His essay
is partly a call to arms. But the evidence (see Weisz's article) indicates
that some fossil−fuel resources may be in trouble within the next
few decades. When physicists suggest that the US has resources and technological
potential to meet the needs of an ever−growing economy, it's like
inviting the public to dinner without having checked to see if there
is sufficient food in the cupboard.
Most educated people understand that populations can't grow forever.
But forever isn't really the issue. Already, population increases and
consumer demand are taking big bites out of our energy resources. Of
natural gas, Moniz and Kenderdine wrote that "US consumption represents
roughly half of that for the industrialized world. . . . Developing
Asia, Central America, and South America . . . are each expected to
triple their demand over the next twenty years." A geological study
published in 2003 reports that per capita annual production of natural
gas is decreasing in Canada, Mexico, and the US.5 Production
of natural gas in North America may be near the start of its terminal
Of petroleum, Moniz and Kenderdine reported that world oil consumption
is expected to grow by 60% in the first two decades of the 21st century
and that China expects a five−fold increase in vehicles by 2020.
Some optimistic researchers include in their tabulation of world reserves
the oil shales of western Colorado (about 500 billion barrels); the
Athabasca Oil Sands of Alberta, Canada (about 300 billion barrels, potentially);
and the heavy oil under Venezuela (about 2 trillion barrels).6
Those quantities are huge compared to the US annual consumption of approximately
6 billion barrels, but the important question to ask is, What is the
net energy gained after investing the energy it would take to recover
those very hard−to−extract resources? Physicists must include
the net energy in any recommendations that we make to use those fuels
in the future.
Moniz and Kenderdine also wrote about "products derived from gas−to−liquid
conversion [meaning natural gas], gasification of coal, and biomass."
But if natural gas in North America is near the start of its terminal
decline, there won't be much left to convert into other potential uses.
They argued that CO2 emissions can be reduced by switching
to "less carbon−intensive fossil fuels—for example, natural
gas instead of coal for electricity generation—[this is an] economical
way to reduce carbon intensity and meet growing demand." But the switch
from coal to natural gas to generate electricity in the US was made
a decade or so ago and the predictable effects are now evident: declining
production, imminent shortages, and the rapid price increases of natural
Researchers continue to debate when the peak of world petroleum production
will be reached. Analytical estimates range from 20047,8
to about 2025.9 But from a per capita perspective, world
petroleum production reached a peak in the 1970s (see the figure). I
believe future historians may identify this peak as one of the most
important events in all of human history.
The silent lie
In the Physics Today essay and article, population growth is given
as a cause of the problems identified, but eliminating the cause is
not mentioned as a solution. We are prescribing aspirin for cancer.
Indeed, the solutions outlined in the articles would only make the problems
worse. To appreciate what I mean, consider the "theorems" of economist
The Dismal Theorem:
If the only ultimate check on the growth of populations is
misery, then the population will grow until it is miserable enough to
stop its growth.
The Utterly Dismal Theorem:
Any technical improvement can only relieve misery for a while,
for so long as misery is the only check on population, the [technical]
improvement will enable the population to grow, and will soon enable
more people to live in misery than before. The final result of [technical]
improvements, therefore, is to increase the equilibrium population,
which is to increase the sum total of human misery.
The Moderately Cheerful Form of the Dismal Theorem:
If something else, other than misery and starvation, can
be found which will keep a prosperous population in check, the population
does not have to grow until it is miserable or starves; it can be stably
In 1970, the CBS broadcaster Eric Sevareid rephrased the theorems
even more bluntly: "The chief source of problems is solutions."11
Physicists develop solutions to problems, but when the underlying
cause of those problems remains neglected, we are effectively perpetuating
a lie—what Mark Twain has called the silent lie:
Almost all lies are acts, and speech has no part in them.
. . . I am speaking of the lie of silent assertion; we can tell it without
saying a word. . . .
For instance: It would not be possible for a humane and intelligent
person to invent a rational excuse for slavery; yet you will remember
that in the early days of emancipation agitation in the North, the agitators
got but small help or countenance from any one. Argue and plead and
pray as they might, they could not break the universal stillness that
reigned, from pulpit and press all the way down to the bottom of society—the
clammy stillness created and maintained by the lie of silent assertion—the
silent assertion that there wasn't anything going on in which humane
and intelligent people were interested.
The universal conspiracy of the silent−assertion
lie is hard at work always and everywhere, and always in the interest
of a stupidity or a sham, never in the interest of a thing fine or respectable.
It is the most timid and shabby of all lies . . . the silent assertion
that nothing is going on which fair and intelligent men [and women]
are aware of and are engaged by their duty to try to stop.12
What do we do?
Here is a list with which to start:
- Acknowledge population growth as a major cause of societal
- Debate the question, Which approach leads to greater general
good: working to stabilize populations or working to spread ever−dwindling
resources among ever−growing populations?
- Research, speak, and write about energy consumption, CO2
emissions, and populations, with an understanding that stabilizing
population is a necessary condition for solving these problems.
- Alter the message given to students in the classroom and
to the public. It is important they recognize that these energy and
related problems cannot be solved without stopping population growth.
The physics community cannot launch a major campaign aimed at stabilizing
the US population. That's not physics. But when physicists assume authoritative
roles to solve the societal problems caused by population growth, professional
responsibility requires that we stress the importance of stopping population
growth as a central part of all solutions. We are not telling lies of
silent assertion in the interest of the tyrannies and shams that Twain
cites. Rather, we are tiptoeing around the issue in the name of political
correctness. We can't be proud of that. As Mark Twain wrote, "[It] is
the most timid and shabby of all lies."12
Albert A. Bartlett is an emeritus professor of physics at the
University of Colorado at Boulder.
1. A. A.
Bartlett, Am. J. Phys. 46, 876 (1978).
2. A. A. Bartlett, Population and Environment 16, 5 (1994).
Reprinted in Renewable Resour. J. 15, 6 (Winter 199798).
3. See T. R. Malthus, in An Essay on the Principle of Population: Text,
Sources and Background, Criticism" P. Appleman, ed., W. W. Norton,
New York (1976).
4. J. M. Simon, The State of
Humanity: Steadily Improving, CATO Policy Rep. vol. 17, no. 5, Cato
Institute, Washington, DC (Sept.Oct. 1995), p. 131. For a critique,
see A. A. Bartlett, Phys. Teach. 34, 342 (1996).
5. W. Youngquist, R. C. Duncan, Nat. Resour. Res. 12, 229
6. W. L. Youngquist, GeoDestinies: The
Inevitable Control of Earth Resources Over Nations and Individuals,
National Book, Portland, OR (1997), p. 215.
A. A. Bartlett, Math. Geol. 32, 1 (2000).
8. K. S. Deffeyes, Hubbert's Peak: The Impending World Oil Shortage,
Princeton U. Press, Princeton, NJ (2001).
D. Edwards, Am. Assoc. Pet. Geol. Bull. 81, 1292 (1997).
10. K. Boulding, in Collected Papers [by] Kenneth E. Boulding,
Vol. 2, Colorado Associated U. Press, Boulder, CO (1971), p. 137.
11. E. Sevareid, CBS News, 29 December 1970, quoted in T. L. Martin, Malice
in Blunderland, McGraw−Hill, New York (1973), p. 23.
12. M. Twain, The Man That Corrupted Hadleyburg and Other Short Works,
Prometheus Books, Amherst, NY (2002), p. 159.
Figure 1. World daily production of petroleum per capita has been
steadily dropping since the 1970s, when it was roughly 2 liters per person−day.
Currently, US consumption is about 4 liters per person−day. As petroleum
production struggles to keep up with growing demand, and as world population
continues to grow, it is unlikely that world per capita production can
ever again rise to the levels reached in the 1970s. (Adapted from ref.
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© 2004 American Institute of Physics