Last month, when I wrote a column headlined "Apocalypse when? Can three experts all be wrong on looming disaster?," I expected that readers would harangue me for taking up ranks with the pessimists. After all, for every doomster, there seems to be a Pangloss reassuring us that all will be well.

Recently in The Japan Times, for example, Ray Kurzweil argued that exponential progress in technology will offer solutions to all our problems before they get the better of us ("Making the world a billion times better"; April 17).

Nice to think so, certainly, though at least one scientist I'll introduce later believes that the exponential function, and our failure to understand it, is precisely why we have so many problems.

In any case, I was wrong. No one wrote to accuse me of being a prophet of doom; just the opposite happened.

Everyone who wrote said the experts — Lester Brown, president of the Earth Policy Institute in Washington, British scientist James Lovelock, and Jeffrey Sachs, director of the Earth Institute at Columbia University in New York — are not critical enough in their assessments.

Several readers in particular, from different corners of the globe, were adamant in their criticism. Each sent me Web site links to check out, and they also stressed that planetary survival hinges on the issue of population.

This column will share some of their comments and some of the people and resources they introduced, so thanks to you all, worldwide, in advance.

Prof. Eric R. Pianka, a biologist at the University of Texas in Austin, didn't waste any words setting me straight:

Hi Steve,

You, like almost everybody, miss the point. Treating the symptoms of overpopulation while denying the cause is like driving into a brick wall at top speed.

We must get out of this state of total denial and face reality. We must confront the source of ALL our problems: Too Many People.

Above all, face reality and THINK.

Best wishes, Eric

If you're interested in knowing more about Pianka's opinions, research and solutions, see his thought-provoking Web site at: www.zo.utexas.edu/courses/THOC/

Another reader, from Switzerland, sent along his Web site address and some pointed criticisms of all three experts.

Dear Mr. Hesse,

Yes. All three "learned experts" are wrong.

Mr. Sachs is wrong because he still believes in economic growth and progress on a planet that has finite space and resources. Hardly any economist gets that point right!

Mr. Brown is wrong because he believes we can at least maintain our present level of exuberant consumption. One has to sound vaguely optimistic to be taken seriously. Optimism and hope and belief in technology are today's civic duties.

And Mr. Lovelock has lost his logic. He is right in saying that many solutions are a scam and a waste of time and effort. But his nuclear solution is tremendously off.

Humanity's problem is not that we don't have enough energy, but that we have too much. The vast amounts of cheap, easy fossil energy have allowed humanity to reach the enormous overshoot of the Earth's carrying capacity, in numbers and in consumption per capita.

The world's population under business-as-usual scenarios is expected to rise to 8.5 billion by 2050 (it is 6.7 billion now), and nobody knows how all those people can live in terms of either space or resources.

Kind regards, Helmut Lubbers

I asked Lubbers in a followup e-mail what he thought we should be doing to get humans and the planet back in balance. He replied:

Relocalization, elimination of motorized transportation, but for emergency services, slowing down in general, using power when nature provides it, i.e., when the wind blows and the rivers carry water, and elimination of all destructive and useless activities, demechanization, and a return to a very frugal lifestyle.

All this will only make sense if people realize that we have far overshot the Earth's carrying capacity, that economic growth means increasing the speed of resource depletion, and that as a logical consequence we have to consciously and democratically contract economic activities and population sizes.

So in sum I think we are lost as long as the BAU (business-as-usual) scenario reigns in this world, Lubbers wrote.

You can visit Lubbers' Web site, an eclectic compendium, at: ecoglobe.ch/

Meanwhile, a third reader, Peter Salonius, provided the most comprehensive comments and links. Salonius is a soil scientist in Canada and he, too, argues that population is overshooting the planet's carrying capacity, resulting in the degradation of ecosystems that already cannot support present population levels.

I have taken the liberty of synthesizing parts of his e-mail with other comments he sent.

Hello Stephen Hesse,

I do hope you have time to run through the material I present below; it is as far as I have gotten after starting to broaden my attention — away from the reductionist soil science that occupied me for about 40 years — toward more holistic/systems deliberations.

Many keen thinkers have understood that the driver that has enabled our numbers to shoot so far over long-term carrying capacity is the planet's one-time gift of fossil fuels, and this overshoot has resulted in our rampant destruction of the biosphere. The global human population before the start of the Fossil-Fuel Revolution was about 1 billion, while it is now about 6.6 billion and rising. These holistic thinkers suggest that without oil, the Earth will only support about 2-3 billion.

The other major factor that has enabled our numbers to shoot so far over long-term carrying capacity is the one-time gift of erodible soils and the vast store of plant nutrients they contained.

William Rees and Mathis Wackernagel have developed the Ecological Footprint Analysis and believe that humanity overshot global carrying capacity sometime in the 20th century, while it is more likely that the human family has been in overshoot for the last 10,000 years, and has been sidestepping this overshoot by further forest destruction for agriculture, migration to new areas, global trade, and the fossil-fuel-dependent motive power, fertilizers, insecticides and herbicides that make modern agriculture possible, Salonius wrote.

Salonius also included two interesting links, one an easy-to-understand slide show on food production and population, and the other an engaging talk by Dr. Albert Bartlett explaining the so-called exponential function.

The slide show, titled "World Food and Human Population Growth," explains how increasing food production to feed a growing population spurs even further population growth.

An important corollary is that industrial agriculture, which we have embraced to feed the hungry masses, is rapidly degrading soils and destroying forest, marine and freshwater ecosystems.

The slide show is the work of Dr. Russell Hopfenberg, a consulting associate at Duke University in North Carolina. You can find it at www.panearth.org

The talk by Bartlett, an emeritus Professor of Physics at the University of Colorado, Boulder, explains the so-called exponential function in simple terms. This may not be the sexiest topic, but Bartlett makes a clear and convincing case for why we all need to have a better understanding of exponentiation. His talk is titled "Arithmetic, Population and Energy."

"Some of these problems are local, some are national, some are global. They're all tied together. They're tied together by arithmetic, and the arithmetic isn't very difficult," begins Bartlett.

He goes on to explain that we need to understand the function better, because our society's addiction to exponential growth is both untenable and undesirable.

Population growth, another exponential threat, is "the immediate cause of all our resource and environmental crises," he warns.

Bartlett makes his point convincingly, with humor and pithy quotes such as this one from Isaac Asimov:

"Democracy cannot survive overpopulation. Human dignity cannot survive overpopulation. Convenience and decency cannot survive overpopulation. As you put more and more people into the world, the value of life not only declines, it disappears. It doesn't matter if someone dies, the more people there are, the less one individual matters," said Asimov.

Clearly, across the globe, from America to Switzerland to Canada, the fate of our planet and the population threat are very real concerns for Japan Times readers. The consensus is that we need to reverse exponential growth of both the numbers of new people and resource consumption, and we need to start now.

As Bartlett notes, this will require educating policy-makers worldwide to the lessons of simple math. "The greatest shortcoming of the human race is our inability to understand this very simple arithmetic," he chides good-naturedly.

Bartlett ends with a quote from the Rev. Martin Luther King on overpopulation: "What is lacking is not sufficient knowledge of the solution, but universal consciousness of the gravity of the problem and the education of the billions who are its victims."

So, while corporations and politicians continue to reassure us that we can squeeze more energy, more food, and more resources from the planet's shrinking reserves, perhaps the best, real solution is to give women and families worldwide the education and support they need to raise just one or two children well — rather than three or more willy-nilly, at the planet's and all children's peril.

A video of Dr Bartlett's talk can be seen at www.youtube.com

Stephen Hesse welcomes readers' comments at [email protected]

A video of Dr Bartlett's talk can be seen at www.youtube.com Stephen Hesse welcomes readers' comments at [email protected]