Gore’s ‘global warming mentor,’ in his own words

Published January 1, 2000

If Swedish chemist Svante Arrhenius is the grandfather of greenhouse warming (ca. 1897), then oceanographer Roger Revelle is certainly its father.

Revelle, who died in 1991, started the remarkable series of measurements of atmospheric CO2 during the Intergovernmental Geophysical Year in 1957. As a visiting professor at Harvard University, he taught a freshman course attended by then-student Al Gore. In his frightening best-seller, Earth in the Balance, Gore claims Revelle as his mentor.

If you know the book, you may be interested in what mentor/scientist Revelle said about global warming. It will make you less frightened.

OMNI interview

In March 1984–15 years ago, mind you–Omni magazine published an extensive interview with Revelle.

Omni: A problem that has occupied your attention for many years is the increasing levels of CO2 in the atmosphere, which could cause the Earth’s climate to become warmer. Is this actually happening?

Revelle: I estimate that the total increase [in CO2] over the past hundred years has been about 21 percent. But whether the increase will lead to a significant rise in global temperature, we can’t absolutely say.

Omni: [If it happens], what will the warming of the Earth mean to us?

Revelle: There may be lots of effects. Increased CO2 in the air acts like a fertilizer for plants. . . . you get more plant growth. Increasing CO2 levels also affect water transpiration, causing plants to close their pores and sweat less. That means plants will be able to grow in drier climates.

Omni: Does the increase in CO2 have anything to do with people saying the weather is getting worse?

Revelle: People are always saying the weather’s getting worse. Actually, the CO2 increase is predicted to temper weather extremes.

Revelle’s letters

In a July 18, 1988, letter to then-Senator Tim Wirth, Revelle cautions that “we should be careful not to arouse too much alarm until the rate and amount of warming becomes clearer. It is not yet obvious that this summer’s hot weather and drought are the result of a global climatic change or simply an example of the uncertainties of climate variability. My own feeling is that we had better wait another ten years before making confident predictions.”

Revelle had made an even stronger statement just a few days earlier, in a July 14, 1988 letter to Congressman Jim Bates: “Most scientists familiar with the subject are not yet willing to bet that the climate this year is the result of ‘greenhouse warming.’ As you very well know, climate is highly variable from year to year, and the causes of these variations are not at all well understood. My own personal belief is that we should wait another ten or twenty years to really be convinced that the greenhouse effect is going to be important for human beings, in both positive and negative ways.”

Revelle’s writings

In the premiere issue of Cosmos, in 1991, Revelle and coauthors S.F. Singer and C. Starr contributed a brief essay, “What to do about greenhouse warming: Look before you leap.” The three write: “Drastic, precipitous and, especially, unilateral steps to delay the putative greenhouse impacts can cost jobs and prosperity and increase the human costs of global poverty, without being effective.”

They continue, “Stringent controls enacted now would be economically devastating, particularly for developing countries for whom reduced energy consumption would mean slower rates of economic growth without being able to delay greatly the growth of greenhouse gases in the atmosphere. Yale economist William Nordhaus, one of the few who have been trying to deal quantitatively with the economics of the greenhouse effect, has pointed out that ‘. . . those who argue for strong measures to slow greenhouse warming have reached their conclusion without any discernible analysis of the costs and benefits.'”

Revelle and his colleagues conclude, “It would be prudent to complete the ongoing and recently expanded research so that we will know what we are doing before we act. ‘Look before you leap’ may still be good advice.”

S. Fred Singer is president of the Science & Environmental Policy Project.