Richard Nixon said he wasn’t a crook. O.J. Simpson said he didn’t kill his wife. The scientists who run the Climatic Research Unit at the University of East Anglia say they are “committed to scientific integrity …and … respectful and informed debate” with climate-change skeptics.

But as Nixon and Simpson eventually discovered, truth has a way of undoing even the most determined stonewall. Now it is the turn of the CRU’s climate scientists - especially its director, Phil Jones - to learn that lesson.

The CRU, a highly influential source of data on global warming, is home to some of the foremost proponents of the scientific “consensus” that climate change is a looming man-made disaster to be reversed at all costs. It is also at the center of “Climategate,” the international furor triggered when thousands of e-mails and documents were hacked from CRU computers and released over the Internet last month.

Assuming the e-mails are genuine, they are nothing short of scandalous. They reveal celebrated climate scientists apparently conspiring to corrupt the peer-review process, to suppress or finesse temperature data at odds with global-warming alarmism, to silence or discredit climate experts who criticize their work, and to hide or eliminate the raw data on which their own much-trumpeted claims have been based.

For years, climate alarmists have insisted their views are validated by the peer-review process, which ensures that only research of highest quality gets published in leading scientific journals or in reports of the UN’s Intergovernmental Panel on Climate Change (IPCC). There is no reason to heed global-warming skeptics, they said, since their findings haven’t made the peer-review cut.

Behind that smug public appeal to scientific authority, however, was what now looks like a concerted effort to blackball the skeptics. In a July 2004 e-mail, for example, CRU director Phil Jones dismisses as “garbage” the work of two dissenters. “I can’t see either of these papers being in the next IPCC report,” he assures fellow scientist Michael Mann of Penn State University. “Kevin and I will keep them out somehow - even if we have to redefine what the peer-review literature is!”

In another e-mail, Mann fumes because the peer-reviewed journal Climate Research published a paper by two noted skeptics, Willie Soon and Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics. “This was the danger of always criticizing the skeptics for not publishing in the ‘peer-reviewed literature.’ Obviously, they found a solution to that - take over a journal!” The only thing to do, he suggests, is rig the peer-review system: “I think we have to stop considering ‘Climate Research’ as a legitimate peer-reviewed journal. Perhaps we should encourage our colleagues in the climate research community to no longer submit to, or cite papers in, this journal.”

Even more disturbing than such contempt for legitimate disagreement is the thread of e-mails in which Jones and other climate scientists discuss how best to evade requests for the raw data underlying their published work. There are repeated recommendations that records be destroyed. “Mike,” wrote Jones last year in an e-mail to Mann regarding the IPCC’s Fourth Assessment Report, “Can you delete any e-mails you may have had with Keith re AR4?” Earlier, referring to requests for the meteorological station data used to build the CRU’s global temperature record, Jones had written that if the skeptics “ever hear there is a Freedom of Information Act now in the UK, I think I’ll delete the file rather than send to anyone.”

You don’t have to agree with the skeptics to be appalled by such anti-scientific behavior. The CRU documents make it only too clear, paleoclimatologist Eduardo Zorita said last week, that much climate science research “is full of machination, conspiracies, and collusion… . The scientific debate has been in many instances hijacked to advance other agendas.” British environmentalist George Monbiot, a fierce critic of global-warming skeptics, vented his fury over the Climategate revelations. “Opaqueness and secrecy are the enemies of science,” he wrote in the Guardian. “No one has been as badly let down by the revelations in these e-mails as those of us who have championed the science.”

Amid the uproar, Jones stepped down yesterday. As Nixon and OJ could have told him, stonewalling rarely succeeds.