On screen, the man widely regarded as the grandfather of climate denial appears a genial participant in a newly-released expose about industry’s efforts to block action on global warming.

But behind the scenes, Fred Singer has lobbied fellow climate deniers to try to block the film, Merchants of Doubt, and raised the prospect of legal action against the filmmaker.

“It’s exactly what we talk about in the film. It’s a product of a playbook which is to go after the messengers and attack and try and change the conversation, and try to intimidate, and it is very effective,” said Robert Kenner, the filmmaker.

Since the film’s release, Kenner, and Naomi Oreskes, a Harvard professor and co-author of the book on which the documentary is based, have come under attack in climate denier blogs, and in email chains.

The backlash appears to have been initiated by Singer, 90, a Princeton-trained physicist who has a cameo in the film.

Singer dismisses the dangers of secondhand smoking. He also denies human activity is a main cause of climate change. “It’s all bunk. It’s all bunk,” a seemingly jovial Singer says in the film.

By last autumn however Singer appeared to be having second thoughts about his participation in the project.

In a series of email exchanges with a global network of climate deniers from Christopher Monckton to the Harvard-Smithsonian scientist Willie Soon, Singer raises the prospect of blocking the film’s release.

“Gents, Do you think I have a legal case against Oreskes? Can I sue for damages? Can we get a legal injunction against the documentary?” Singer wrote last October. “I need your advice.”

In another email, Singer asks the group: “Has she finally gone too far?...Maybe this is the right time for legal action. What say you?”

The cry for help got an immediate response. Monckton offered to help draft a legal complaint against Oreskes.

James Enstrom, an epidemiologist who dismisses the public health dangers of air pollution, advised Singer he had “a very strong case” for complaining to Oreskes’s employers.

“I suggest you attack Oreskes by filing short grievances with Harvard and Stanford,” Enstrom wrote.

“Good thought,” Singer said.

By March 6, Singer had moved on to challenging Kenner directly, raising the prospect of legal action. In a letter, he claimed he was called “a liar for hire” in the documentary.

The phrase does not appear in the film, Kenner said. However, it does appear in media coverage of the film.

“I have some experience with libel suits,” Singer writes in the letter. “I would prefer to avoid having to go to court; but if we do, we are confident that we will prevail.”

He goes on to criticize Kenner for basing his film on the Oreskes book, saying: “It is rather too bad that you got mixed up with Naomi Oreskes. She claims to be a historian of science; unfortunately, she has only demonstrated that she’s a great polemicist with a rather well-defined bias.”

On March 9, Enstrom also wrote to Kenner, echoing Singer’s claims. “I am concerned that your film makes statements about Dr. Singer that could be considered defamatory,” he wrote. “Because your film is based on the book ‘Merchants of Doubt’ by Naomi Oreskes, PhD, you need to know about her contentious and controversial background.”

Enstrom called on Kenner to arrange a debate between Oreskes and Willie Soon, the Harvard-Smithsonian researcher exposed for taking industry funding, when his film is screened in Boston later this month.

Singer did not respond to requests for comment. Oreskes said such attacks were typical of Singer. “This is what he does.” she wrote in an email. “We are not intimidated because we know that our work is factual, based on years of research, and backed up by extensive documentation... And we never used the term he accuses us of using, so there is no basis for complaint.”

On Tuesday, meanwhile, Steve Milloy, a blogger who denies the existence of climate change published a blogpost about Kenner’s brother, a 60s era radical.

“I am really just coming on their radar as the film is coming out, and the attacks are just heating up,” Kenner said.

Originally published by The Guardian