TCS Daily


Humanists vs. Naturalists

By James K. Glassman - May 9, 2003 12:00 AM

The tide is starting to turn in the debate over global warming. Challenges to the extremist Kyoto orthodoxy are coming from unlikely places.

Consider a remarkable piece by renowned physicist Freeman Dyson in a surprising venue: the New York Review of Books, bible of the transatlantic liberal intelligentsia.

In the lead article of the May 15 issue, Dyson, who is professor of physics emeritus at the School of Natural Sciences of the Institute for Advanced Study at Princeton, has written a lengthy essay-review of "The Earth's Biosphere: Evolution, Dynamics and Change" (MIT Press), by Vaclav Smil, distinguished professor of geography at the University of Manitoba, Canada, and the author of many books on energy and the environment.

In 2001, Smil won the Award for Public Understanding of Science and Technology from the American Association for the Advancement of Science. Dyson, himself a prolific author, is a winner of the prestigious Enrico Fermi Award.

Dyson begins: "It is refreshing to read a book full of facts about our planet and the life that has transformed it, written by an author who does not allow facts to be obscured or overshadowed by politics." Smil, Dyson continues, is well aware of the controversy over the effects of humans on climate change and biodiversity, but Smil doesn't take sides. Not enough is known. Instead, Smil "emphasizes the enormous gaps in our knowledge, the sparseness of our observations, the superficiality of our theories."

This is precisely the point the Bush administration has been making for the past two years in the face of withering criticism from Europeans. We simply do not know enough to commit hundreds of billions of dollars toward the kind of solutions demanded by the Kyoto Protocol. We need more research.

So here are an author and a reviewer who understand that the biosphere is a complicated case and that, in Dyson's words, "when we are trying to take care of a planet, just as when we are taking care of a human patient, diseases must be diagnosed before they can be cured."

What is clear, both from Smil's book and from new revelations about climate change that seem to be appearing weekly, is that our knowledge is scanty and evolving and that taking drastic steps to cool off the planet are likely to prove futile - or much worse.

For example, a new study by Willie Soon and Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysicists (Baliunas is also co-host of TCS where Soon is Science Director) and other colleagues looked at more than 200 studies and found that the earth was warmer 1,000 years ago - long before industrial emissions of greenhouse gases - than it is today. Other recent research has cast doubt on the computer models used to predict climate change, finding, for example, that warming in the past appeared to precede rises in carbon dioxide - not the other way around, as the models suppose.

In his essay, Dyson focuses on Smil's complex views on the "biosphere of carbon dioxide in the atmosphere." As a result of the burning of fossil fuels, CO2, writes Dyson, is increasing at a rate of about one-half a percent per year. This increase has two consequences - one physical and one biological. The key questions are these: "Are the physical or biological effects more important? Are the effects, either separately or together, beneficial or harmful?" The answers are, to put it mildly, unclear.

On the physical side, Dyson writes that, as a result of the greenhouse effect, "warming mainly occurs" where air is cold and dry, "mainly in the arctic rather than in the tropics, mainly in winter rather than in summer, and mainly at night rather than in the daytime. The warming is real, but it is mostly making cold places warmer rather than making hot places warmer. To represent this warming by a global average is misleading." Also, he says, "It is better to use the phrase 'climate change' rather than 'global warming' to describe the physical effects of carbon dioxide."

Dyson shows that Smil's examination of biological effects also casts doubt on the dogmatic position of radical environmentalists. First, experiments in greenhouses reveal that "an atmosphere enriched with carbon dioxide" causes plant yields to increase "roughly with the square root of the carbon dioxide abundance."

This is important, Dyson writes, because there is so little CO2 available to plants. More CO2 will almost certainly mean more plant growth and biomass. This growth will "cause an increased net transfer of carbon from the atmosphere into the topsoil" and, while hard to quantify, "the possible effect on the topsoil reservoir will not be small."

The conclusion is striking: "The increase of carbon dioxide in the atmosphere over the entire earth could be canceled out by an increase of topsoil biomass of a tenth of an inch per year over the half of the contiguous United States." In other words, the biosphere could produce a kind of equilibrium, where more CO2 in the air leads to more plant growth and biomass, which in turn trap more CO2. We can't know for sure. "All we can say is that this is a theoretical possibility and ought to be seriously explored."

And, speaking of climate change, what about a new ice age? Dyson reminds us that "a natural cycle has been operating for the last eight hundred thousand years. In each hundred-thousand-year period, there is an ice age that lasts about ninety thousand years and a warm interglacial period that lasts about ten thousand years. We are at present in a warm period that began twelve thousand years ago, so the onset of the next ice age is overdue." Perhaps human activity has prolonged the interglacial period - which, all things considered, sounds pretty good.

Finally, Dyson says that Smil says that questions like climate change do not merely involve a disagreement about facts, but a "deeper disagreement about values" - which he sees as a conflict between naturalists and humanists.

"Naturalists believe that nature knows best. For them the highest value is respect for the natural order of things. Any gross human disruption of the natural environment is evil. Excessive burning of fossil fuels, and the consequent increase of atmospheric carbon dioxide, are unqualified evils."

But humanists, on the other hand, "believe that humans are an essential part of nature [with] the right to reorganize nature so that humans and biosphere can survive and prosper together." To humanists, "the greatest evils," writes Dyson, "are war and poverty, underdevelopment and unemployment, disease and hunger."

And here is Dyson's powerful conclusion: "The humanist ethic does not regard an increase in carbon dioxide in the atmosphere as evil, if the increase is associated with worldwide economic prosperity, and if the poor half of humanity gets its fair share of the benefits."

Smil and his hero, Vladimir Vernadsky - a Russian scientist born in 1863 who, in his book "The Biosphere," was the first to unify the study of the earth with the study of life - come down on the humanist side of the argument. So do I. So, it appears, do more and more people who thoughtfully examine the issues of climate change.

Until very recently, the global-warming debate was dominated by the views of radical environmentalists, politicized scientists and global bureaucrats seeking new mega-projects - all, for reasons both sincere and cynical, falling on the naturalist side of the argument. But since last summer's Earth Summit in Johannesburg, there's been a pronounced change in the air.

Not only are humanist policymakers worrying about the economic consequences of Kyoto-like measures to limit greenhouse gas emissions - especially on developing nations - but, just as important, the scientific foundation of the global-warming argument is under attack as well. Dyson and Smil add impressive intellectual weight to both the humanist and the scientific challenge.
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