Old, Rejected Science
In the last issue of this newspaper, James R. MacNeal disputed my claim in a previous letter that 97% of climate scientists believe in human-induced climate change. He accused me of cherry-picking this figure and went on to “refute” (I think he means “rebut”) my assertions about anthropogenic global warming.
Mr. MacNeal cites two documents — the Heidelberg Appeal and the Oregon Petition — to support his claim that considerable doubt exists among scientists as to the validity of the assertion that human beings are, in part, the cause of climate change. It’s important to examine these two documents.
The Heidelberg Appeal was indeed signed, as Mr. MacNeal asserts, by 4,000 scientists including 72 Nobel Laureates and was published at the start of the Rio Earth Summit. What he neglects to mention, however, is the date of this appeal: 1992. The Heidelberg Appeal represents old science, not a current consensus among climate scientists.
Moreover, the Appeal provides the point of view of scientists from a range of scientific disciplines, not simply climatology. Scientists who are commenting on scientific matters outside their field of specialization are sometimes notoriously wrong about their claims. Linus Pauling, a double Nobel Prize winner in chemistry and peace, floated a theory about the health benefits of consuming large doses of Vitamin C, a theory that has been roundly debunked. Scientists who embrace creationism are very rarely biologists; they typically hail from chemistry and physics.
Other aspects of the Heidelberg Appeal raise questions. The appeal was funded primarily by the tobacco and asbestos industries to advance their own versions of science. The signatories to the Appeal were, for the most part, scientists who had little dispute with the idea of human-induced climate change; they were simply trying to defend the general enterprise of science in the face of an environmental movement led largely by activists hostile to science. Indeed, the original appeal said nothing about climate change. Language about global warming was added later by the author of the appeal in a clear example of bait and switch.
The Oregon Petition, another effort at climate change denialism, has an even dodgier reputation. Like the Heidelberg Appeal, it represents old science, having been first circulated in 1998. Again, Mr. MacNeal is correct in asserting that the document was signed by 31,072 American scientists, including 9,021 Ph.D. holders. But many scientists have questioned the method used to collect these signatures. Indeed, pranksters were able to submit successfully such names as Charles Darwin and Geri Halliwell, a member of the Spice Girls. Even discounting these spurious entries, only 39 of the signees were climatologists; the vast majority were from engineering and general science. The National Academy of Sciences has rejected the claims of the Oregon Appeal.
By the way, the 97% figure I mentioned was not cherry-picked. The figure is generally accepted as the percentage of climate scientists (not scientists in general) who believe in anthropogenic global warming. NASA has verified that figure.
John McBratney
Munson Township
