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October 24, 1991

Dr. Richard A. Kerr
1333 H Street, NW
Washington, DC 20005

Dear Dr. Kerr:

I received your 30 September response to my 24 June letter, and respond to points you raise. I do not like having to write these letters. I have a warm spot in my heart for Science magazine. Some years ago, wonderful people at Science gave me a chance that changed my career by publishing my "A terminal Cretaceous greenhouse..." paper (Science, 1978). However, events involving the K-T debate, the subject of our letters, have interfered with the processes of science, and I see no way other than to address problems with the hope that they can be rectified.

I'm not alone in experiencing distress over your Science coverage of the K-T. A couple years ago, a prominent scientist spoke of taking legal action against Science because of you. One was so anguished over the futility of trying to cope with your one-sided influence upon the public that he nearly dropped out of K-T research.

For your "It is flattering that you believe my writing has been so influential," I believe that you have been the single most influential journalist at promoting the Alvarez asteroid to the American public. My reason: for 10 years, you have covered K-T extinctions conferences for Science magazine, the prestige of which has provided you credibility, and ready access to a readership that includes the 135,000 members of AAAS who receive Science, and the multitudes who read Science in school, and public libraries. Your consistent support of the asteroid, in spite of the evidences of volcanic influence in the K-T extinctions, and your lurid titles such as "An impact but no volcano," "Huge impact is favored K-T boundary killer," and "Yucatan killer impact gaining support" have continually reinforced the asteroid theory to an unsuspecting public.

Science influences the education of our nation's youth. The scientific journals where the real K-T debate is happening are at universities, and not readily available to the public. Many high school science teachers without access to the journals depend on Science for overviews to present to their students. You blanked out the volcano side of the K-T extinction debate to a generation of our nation's teachers and their students. I have had experience with your influence on education.

Each year, I teach large sections of freshman Historical Geology, in which I cover the K-T extinctions. Over the past decade many, if not most, college freshmen have expressed belief that an asteroid impact killed the dinosaurs. Most do not know that the Deccan Traps volcanism, one of the greatest volcanic events in earth history, straddles the K-T boundary, and that it was coeval with a long-duration carbon cycle perturbation, climatic warming, iridium spikes, "Strangelove" oceans, and long-duration biological perturbations and extinctions, etc. Your K-T reports in Science have denied a generation of our nation's youth some of the most fundamental natural processes of our planet. The K-T extinctions are likely the classic example in earth history of what a greenhouse can do to life of our planet. We face a potential greenhouse today.

Each year, student journalists practice on me. They often have your Science reports. I took the Ph. D. in geology from Stanford and all course work for the Ph. D in biology as a foundation for my research, have done multidisciplinary research on K-T extinctions since the 1970s, originated the K-T greenhouse theory, did the first work linking the Deccan Traps volcanism to a K-T greenhouse, and have developed a greenhouse physiological killing mechanism, etc., and I must defend myself against a Science staff writer!

Scientists must spend years interpreting data, going through time-consuming peer-review, and trial-by-fire of having our ideas examined by the scientific community. You, however, publish what you please, and have quick access to the public via Science. You may have had more influence on molding public opinion on the K-T extinctions than some scientists who have spent much of their careers doing K-T research. That one person under the mantle of the American Association for the Advancement of Science can exert so much promotional and demotional power over science is troubling.

In addition to the general public, those who fund science, and our nation's political leaders, are influenced by Science. You seem intent on persuading everyone that the K-T debate is over, and that the impactors have won. How else can one interpret your statements in the Washington Post (May 7, 1989) that "Scientists have at last concluded a 10-year debate"...and "the evidence is solidly on the side of an asteroid." Scientists have not concluded the K-T debate. You know that data are still being collected, and interpreted. The continual "spin" you put on the K-T is disruptive of the processes of science, and misleading to the readers of Science magazine.

Some points in your letter seem designed to cover your behind. You note that "You may not agree, but I believe my coverage has been driven by the evidence found at the K-T boundary. That evidence, ever since the discovery of the iridium layer, has built progressively and inexorably toward confirmation of a large impact at the moment of the K-T boundary." You are Ph. D.-level professional journalist who has covered the K-T for 10 years and have heard too many K-T talks, and know the K-T story too well, to speak with such beguiling simplicity.

One might argue that you have followed a decade-long consistent agenda of promoting the Alvarez asteroid, excluding and demoting its volcanic opposition, and attempting to persuade the public that the debate is over at a time when you know that scientists are still collecting and interpreting data.

For your "at the moment of the K-T boundary," you have been around too long not to know that a nearly universal hiatus at the K-T boundary precludes our knowing what happened at the "moment of the K-T boundary." Commonly, several million years of the original K-T boundary strata are missing. For the most complete sections recorded, it cannot be known for certain that they are actually complete. The terrestrial K-T and marine K-T boundaries have not been demonstrated to be globally isochronous. The "moment" is not available to science.

Similarly, you have covered the K-T too long not to know that evidence at the K-T boundary is not the whole story, and that the K-T extinctions can be understood only by studying them within a time span that includes the K-T boundary. I know that you have heard at meetings that the Deccan Traps volcanism straddles the K-T boundary, and that the duration of its eruptions was coeval with long-duration perturbations of the C-13 and O-18 isotope records, iridium spikes, "Strangelove" oceans, and long-duration biological perturbations, and extinctions, etc. Unfortunately for the readers of Science, you have largely left these data critical to understanding the K-T extinctions out of your Science reports for the past 10 years.

For your "evidence for a volcanic source for the exotic materials found at the boundary has been piddling to nonexistent," it is inexcusable in light of your experience that you would present the "exotic material" iridium (that provided the original basis for the Alvarez asteroid) as unequivocal evidence of an impact event. Iridium is being released today by the same hot spot volcano (Reunion) that produced the K-T Deccan Traps 66 million years ago. How can you possibly not know that iridium is not unequivocal evidence of an asteroid impact event?

For the other "exotic material" taken to reflect an impact, the shocked minerals remain controversial as to origin. You know that, having heard numerous talks on the subject. The Rocky Mountain K-T shocked minerals (and iridium) do not represent primary air-fall deposition from an impact event, but were washed into swamps by rivers and streams. The Caribbean shocked minerals are controversial on whether they reflect impact or volcanism.

For the elusive K-T impact crater, your report "Yucatan Killer Impact Gaining Support" (Science, 1991, v. 252, p. 377), notes for the Chicxulub structure that if Shoemaker is "right, the 10-year search for the crater that marked the end of the age of the dinosaurs will be over." This is sensational sounding stuff for Science readers, and more evidence that the debate is about over. However, Chuck Officer tells me that Chicxulub is not an impact crater. You allow impactors almost exclusive access to the public through Science, no matter how premature, unsupported, or outlandish, their claims. Your report cites only impactors (Shoemaker, Hildebrand, Sharpton, Kring, Boynton, and Hut), and exemplifies your biased Science K-T coverage.

To sum up the status of the asteroid theory, the iridium is equivocal, the shocked minerals are controversial, and an impact crater has not been confirmed. And you tell the world that the K-T debate is over, and that the impactors have won! One might argue that you control the knowledge that Science readers get on the K-T debate, and that you have done so in a consistent pattern for 10 years.

Your "In the end, it was the overwhelming evidence published in peer-reviewed journals that ruled the day." overwhelms me. What can motivate your attempts to convince people that the debate is over when you clearly know that it is not?

The K-T debate could have been great for journalists, scientists, and the public, alike. Unfortunately, it involved journalistic bias, attempts to shut down the debate prematurely, bullying opponents to silence them, damaging careers, and even seemingly "stacking" a conference to favor the asteroid.

Scientists who attended the Snowbird II extinctions conference (convened by the NAS and LPI) indicated that it was staged to allow asteroid advocates to overwhelm volcanists. Notably, most leading K-T volcanists such as Courtillot, Cisowski, Crocket, Loper and McCartney, Hansen, and Rice were relegated to the insignificance of poster sessions. You then proclaimed in Science and the Washington Post that the debate was over, and that the impactors had won. Could you not see the asteroid versus volcano imbalance at Snowbird II, or was it not important to you?

You are but part of the Science system. Science, itself, has presented a lopsided coverage favoring the asteroid (letter to Science editor, Koshland, enclosed). A foremost K-T researcher told me recently that her manuscript to Science (not helpful to the asteroid) was marked "No public interest." It was not even sent out for review. You have reportedly stated that "Science should never have published the two articles" by Officer and Drake, and Hallam, and that "it would not be appropriate to submit manuscripts to Science which were contrary to the impact hypothesis." These acts do not accord well with the concept of an American Association for the Advancement of Science.

Compared with the S&L scandal, abysmal educational achievements of our youth, unemployment, drug infestation, spiralling crime rates, and crumbling away of America's foundations, a Science staff writer's promotion of an asteroid to the American public for 10 years may seem like small potatoes. However, the hundreds of millions to billions of dollars cost to the American tax-payers for an asteroid "Spacewatch"-type program instituted and implemented by the impact community are very big potatoes, indeed.

Your peculiar 10-year promotion of the asteroid in Science seems to have paved the way for such a program.


Dewey M. McLean
Professor, and Director of Earth Systems and Biosphere Evolution Studies

cc: Science editor, Dr. Daniel Koshland; AAAS President, Dr. Leon M. Lederman; AAAS President-elect, Dr. F. Sherwood Rowland

Copyright © 1991 Dewey M. McLean