Sir

Your News story “Salt sellers challenge US health agency using data-quality act” (Nature 433 671; 2005), suggests that a lawsuit filed by the Salt Institute represents “the first time that a petitioner has actually sued under the Data Quality Act”. This is not the case, although the ruling that the Salt Institute is appealing was the first verdict given in a case brought under the federal Data Quality Act.

In August 2003 a conservative advocacy group, the Competitive Enterprise Institute, filed a suit claiming violations of the act against President George Bush and John Marburger, director of the White House Office of Science and Technology Policy (OSTP). The most important claim was that reports by the US National Assessment of the potential consequences of climate change (USNA) used results from two different global climate models to construct scenarios of future climate (see National Assessment Synthesis Team, Climate Change Impacts on the United States, Cambridge Univ. Press, Cambridge, 2000) — which therefore violated the act because one of the two scenarios had to be in error.

In November 2003, just as the Department of Justice was preparing to file its response, the parties accepted a ruling of “dismissal with prejudice”, meaning that the lawsuit could not be refiled. Although the Department of Justice did not release its brief, it had apparently made a strong argument against the absurd notion that projections of the future must be proven accurate in advance.

The OSTP nonetheless ordered that a notice be added to USNA web pages, indicating that the reports “were not subjected to OSTP's Information Quality Act Guidelines”. This implies that the USNA report was not properly reviewed and would not meet the OSTP guidelines. This is misleading at best, as the report was subjected to a four-stage review that was more comprehensive than called for by the act. In addition, the OSTP guidelines did not exist or apply at the time that the USNA was released.

Attempts by the USNA's lead authors and contributors (including myself) to get this notice removed or modified have failed, leaving in place an unfair criticism of the assessment's widely accepted findings.