Yes it was.
Oh fergoshsakes, read what the NAS said about it.
STATEMENT BY THE COUNCIL OF THE NATIONAL ACADEMY OF SCIENCES REGARDING GLOBAL CHANGE PETITION
April 20, 1998
The Council of the National Academy of Sciences (NAS; http://www2.nas.edu/nas/) is concerned about the confusion caused by a petition being circulated via a letter from a former president of this Academy. This petition criticizes the science underlying the Kyoto treaty on carbon dioxide emissions (the Kyoto Protocol to the Framework Convention on Climate Change), and it asks scientists to recommend rejection of this treaty by the U.S. Senate. The petition was mailed with an op- ed article from The Wall Street Journal and a manuscript in a format that is nearly identical to that of scientific articles published in the Proceedings of the National Academy of Sciences (http://www.pnas.org/nas/). The NAS Council would like to make it clear that this petition has nothing to do with the National Academy of Sciences and that the manuscript was not published in the Proceedings of the National Academy of Sciences or in any other peer-reviewed journal.
The petition does not reflect the conclusions of expert reports of the Academy.
In particular, the Committee on Science, Engineering, and Public Policy (http://www2.nas.edu/cosepup/) of the National Academy of Sciences, the National Academy of Engineering (NAE), and the Institute of Medicine (IOM) conducted a major consensus study on this issue, entitled Policy Implications of Greenhouse Warming (1991,1992; see http://www2.nas.edu/climate-change/). This analysis concluded that " ...even given the considerable uncertainties in our knowledge of the relevant phenomena, greenhouse warming poses a potential threat sufficient to merit prompt responses. ... Investment in mitigation measures acts as insurance protection against the great uncertainties and the possibility of dramatic surprises." In addition, the Committee on Global Change Research of the National Research Council, the operating arm of the NAS and the NAE, will issue a major report later this spring on the research issues that can help to reduce the scientific uncertainties associated with global change phenomena, including climate change.
If it didn't look enough like a PNAS article to cause confusion, why would the NAS council publish a statement worded like this?
Please explain why this makes the petition a "hoax".
Could be propaganda to get people to ignore the petition.