The report found credence in allegations that National Public Radio was denied access to top global warming scientist James Hansen. It also found evidence that NASA headquarters press officials canceled a press conference on a mission monitoring ozone pollution and global warming because it was too close to the 2004 presidential election.

In addition, the report detailed more than a dozen other actions in which it said the NASA public affairs office unilaterally edited or downgraded press releases having to do with global warming or denied access to scientists.

NASA public affairs officials criticized by the report called it wrong, saying they were always open and truthful.

Not so, according to the report. The report did not directly accuse them of lying, but used more nuanced terms such as "mendacity" and "dissembling." The space agency complained those terms were unjust.

The report concluded that "inappropriate political posturing or advantage" was behind some of these actions.

NASA and the Bush administration instantly drew criticism as a result of the report.

"Our government's response to global warming must be based on science, and the Bush administration's manipulation of that information violates the public trust," said Sen. Frank R. Lautenberg, D-N.J.