The study (pdf.) – Redacting the Science of Climate Change: an investigative and synthesis report – took a year to complete and compiles information from dozens of interviews and thousands of FOIA disclosures, internal documents and public records. It illustrates an organized and secretive White House effort beginning in 2001 to restrict scientists’ ability to accurately communicate their research results to the media, the public and Congress.

The report said the administration altered press releases, muzzled scientists who spoke openly and, frequently, routed requests for information about sensitive research to the White House. The report focuses primarily on National Oceans and Atmospheric Administration but includes information on similar tampering at NASA and the EPA.

Although evidence of the Bush administration playing politics with climate-change science has trickled out in the media for some time, the report assembles many of the more egregious offenses. Tarek Maassarani, the report’s author, testified today before the House Science Committee hearing on political interference in science research.

Here’s the RealPlayer webcast from today’s hearing.