A version of the Heidelberg Appeal was published in the June 1, 1992 Wall Street Journal over the signatures of 46 prominent scientists and other intellectuals. It has subsequently been endorsed by some 4,000 scientists, including 72 Nobel Prize winners. It has also been enthusiastically embraced by critics of the environmental movement such as S. Fred Singer of the Science and Environmental Policy Project. Conservative think tanks frequently cite the Heidelberg Appeal as proof that scientists reject the theory of global warming as well as a host of other environmental health risks associated with modern science and industry. Its name has subsequently been adopted by the Heidelberg Appeal Nederland Foundation, which was founded in 1993 and disputes health risks related to nitrates in foods and antibiotic-resistant bacteria. However, the Heidelberg Appeal itself makes no mention whatsoever of global warming, or for that matter of pesticides or antibiotic-resistant bacteria. It is simply a statement supporting rationality and science.
Parts of the Heidelberg Appeal in fact appear to endorse environmental concerns, such as a sentence that states, "We fully subscribe to the objectives of a scientific ecology for a universe whose resources must be taken stock of, monitored and preserved." Its 72 Nobel laureates include 49 who also signed the "World Scientists' Warning to Humanity," which was circulated that same year by the liberal Union of Concerned Scientists (UCS) and attracted the majority of the world's living Nobel laureates in science along with some 1,700 other leading scientists. In contrast with the vagueness of the Heidelberg Appeal, the "World Scientists' Warning" is a very explicit environmental manifesto, stating that "human beings and the natural world are on a collision course" and citing ozone depletion, global climate change, air pollution, groundwater depletion, deforestation, overfishing, and species extinction among the trends that threaten to "so alter the living world that it will be unable to sustain life in the manner that we know." More recently, 110 Nobel Prize-winning scientists signed another UCS petition, the 1997 "Call to Action," which called specifically on world leaders to sign an effective global warming treaty at Kyoto.
One notable signer of the Heidelberg Appeal was the late Linus Pauling, the world's only recipient of two Nobel Prizes (for chemistry and for peace). At the time the Appeal was circulated, Pauling had become associated with a controversial nutritional theory that advocated massive daily consumption of vitamin C. Although his earlier work is widely praised, his theories regarding vitamin C have been almost universally dismissed as pseudoscience. It appears, therefore, that (1) even Nobel laureates sometimes practice pseudoscience, and (2) even the practitioners of pseudoscience believe they are against it.