Climate researcher Michael E. Mann outside the Prince William County courthouse on Tuesday. (Tom Jackman/The Washington Post)

The case again centers around the activities of former U-Va. professor and climate scientist Michael E. Mann, one of many researchers who believe human activity has contributed to global warming. Last year, Cuccinelli sought Mann’s work papers, to investigate whether Mann had fraudulently obtained grants to study the subject. But while Cuccinelli’s efforts bogged down in the Charlottesville courts, Prince William Del. Robert Marshall and two members of the American Tradition Institute filed a FOIA request for the same documents. And when U-Va. didn’t comply promptly, Marshall and the ATI filed a lawsuit in May in Prince William County.

There are apparently about 12,000 e-mails being sought by the ATI, and U-Va. is resisting turning over most of them. On Tuesday in court, both sides exchanged harsh rhetoric, Mann’s request to become a party to the case was granted, and a judge said he would order a third party to review which e-mails should be released and which ones were exempt from Virginia’s FOIA laws.

The American Tradition Institute describes itself as a think tank out to ”restore science, accountability and liberty to the environmental policy debate,” and act as a “counterbalance to environmental extremism.” Its top lawyer is David W. Schnare, a former attorney for the Environmental Protection Agency who began working for ATI, and suing U-Va., even while he was with the EPA. He retired Sept. 30.

Schnare has blogged and written extensive articles about the alleged fraud behind man-made climate change research, and he has a Ph.D. in environmental management. With his law and science background, he is a formidable adversary for the climate change team. In this video, he discusses the theory behind ATI’s Environmental Law Center.

Lawyers for U.-Va. said in court Tuesday they were surprised to learn that Schnare was still employed by the EPA until very recently. That, combined with a string of ATI press releases in the case after a protective order had been issued, caused U-Va. lawyers Richard C. Kast and Madelyn Wessel to question Schnare’s ability to serve as both lawyer and ”cheerleader from the bully pulpit for ATI.”

Briefly, some background: Those who question man-made climate change were heartened when a cache of thousands of e-mails between scientists was leaked in 2009, including some from Mann, who is now the director of the Penn State Earth System Science Center. Some said the e-mails showed that scientists were trying to manipulate climate data in favor of their theories; six subsequent investigations have found that to be untrue.

Still, in 2010 Virginia’s Cuccinelli went after Mann’s e-mails at U-Va. An Albemarle County judge ruled he hadn’t shown good cause for obtaining them, and the attorney general appealed.

In January of this year, Marshall and ATI tried a different approach and filed a FOIA with U-Va. When the university didn’t immediately cough up everything, Marshall and ATI filed suit in Prince William, presumably away from the home court advantage U-Va. enjoyed in Albemarle County.

Because of Marshall’s involvement, all the Prince William circuit judges recused themselves, and retired Fairfax Circuit Court Judge Gaylord L. Finch Jr. was brought in. Finch entered an order telling U-Va. to comply, and the school turned over about 2,000 e-mails that apparently did not contain any particularly juicy info.

And now the fight is on in Manassas.

U-Va. said in court papers that it wants to protect the “confidential scholarly and scientific communications of University faculty.” Mann said outside the courtroom that scientists banter candidly, sometimes heatedly, over important issues. “You need to be able to bounce ideas off each other,” Mann said, “that aren’t always ready for prime time.” He noted that various scientific organizations have urged U-Va., and the courts, to resist ATI’s inquiries.

“The issue isn’t FOIA,” Mann said. “It’s a partisan witch hunt.”

Schnare disagreed. “The public has a right to see that these professors are following their own university’s rules,” he said. “This is about the balance between the public’s right to know under FOIA, and the university’s need to protect academic freedom.”

Schnare said he wants to dig into Mann’s research. “You want to know what are the assumptions? What are the records? We have ‘Climategate’ e-mails to show he can’t even find the data.” He said U-Va. had already spent more than $750,000 in legal costs to keep the e-mails secret.

Mann hired a lawyer and asked to intervene in the case in the event U-Va. has different ideas about how to protect his work. His lawyer, Peter Fontaine, told Finch that ATI was “really an extremist group with a political agenda, expending a lot of time, money and resources in an attempt to destroy Dr. Mann’s reputation.” Finch allowed Mann into the case.

Now the two sides must determine what’s releasable and what’s not, but they don’t trust each other. So Finch told them to get together and figure out a third party who can review all of Mann’s e-mails and recommend which ones can be released to ATI. They are scheduled to report back to him next month, in a key stage of “a rare case,” Schnare said, “that will set the stage for FOIA for many many years to come.”

This post has been updated to correct two names.