- PhD, Fluid Mechanics & Wind Engineering (1990). , 
- Political Science Graduation Diploma, USAF Air War College (1987). 
- MS, University of Utah, Air Pollution & Dispersion Meteorology (1972). 
- BS, Meteorology, University of Utah (1966). 
- BS, Civil Engineering, Virginia Military Institute (1965). 
Karl F. Zeller is a retired US Forest Service meteorologist. According to his profile at ResearchGate, Zeller works at the program for fire, fuels, and smoke sciences (FFS) at the US Forest Service and does research in fluid dynamics, civil engineering, and environmental engineering. 
According to his CV, Zeller claims to have worked for numerous private consulting firms and also in the “fields of meteorology and air pollution” for the Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), The Bureau of Land Management, and the USDA Forest Service. For 26 years he worked as a part-time Air Force Reservist Weather Forecaster. 
Zeller and his colleague Ned Nikolov, who used to work together at the forest service, were the subject of controversy when they were caught publishing a paper under pseudonyms Den Volokin and Lark ReLlez (their names spelled backwards) multiple times from 2014 to 2016. In their research, they propose an alternate theory to the generally accepted greenhouse effect and suggest that greenhouse gas emissions are not contributing to global warming. 
Nikolov and Zeller suggest that atmospheric pressure is the cause for warming, counter to the accepted science of the greenhouse effect. Professional climate scientist Scott Denning described their theory as “too simple” and said it ignores elements of thermodynamics. However, the two argue that their papers were unfairly rejected not due to the science, but because of their association with the climate change denial blog network.  Another climate scientist, Professor Steve Sherwood, described one paper published in a “sham journal” by Nikolov and Zeller as “laughable.”
According to a profile of Nikolov and Zeller at Coloradoan, Nikolov’s research on climate change is “done on his own time.” 
Stance on Climate Change
September 8, 2017
“We do not call our science a theory. It’s actually a discovery. So, we made a discovery and out of this discovery comes some equations and comes a theory. Um, I did want to say that you know, basically, right now our discovery and our theory is pretty much not accepted by the scientific community. And when I say scientific community, I mean both the conventional climate scientists and also the skeptics and deniers.
“Ned and I, ah, Dr. Nikolov and I do not consider ourselves deniers or skeptics. We consider ourselves scientists. Now, this non-acceptance that I think is based on folks mixing — because of the carbon dioxide — mixing air pollution with climate change.”
August 4, 2017
October 19–21, 2017
Nikolov and Zeller attended the “4th World Conference on Climate Change” in Rome. As DeSmog reported, the conference was hijacked by climate change deniers. While the event claimed to have an organizing committee consisting of representatives from the UN’s World Meteorological Organization (WMO), the European Space Agency, and the European Environment Agency (EEA), when DeSmog contacted the organizations they issued statements distancing themselves from the conference. 
Roger Tattersall (AKA “Tallbloke”) interviewed Nikolov and Zeller about their experience at the conference:
Two members of the “organizing committee,” Nils-Axel Mörner and Franco Maranzana, are also founding members of the Independent Committee on Geoethics (ICG) — a group that, according to another founder Lord Christopher Monckton, was established to investigate climate scientists for fraud. 
View the conference program, with notes by DeSmog:
OMICS 2017 Fourth World Conference on Climate Change (Text)
September 8, 2017
Zeller and Nikolov were guests on Connecting the Dots with Dan Happel, broadcast by the Republic News Network (RNN). The show describes the two as “noteworthy climate scientists” who “both agree that the current greenhouse theory climate models are flawed in their basic assumptions, and lack the requisite scientific testing necessary for credibility.” 
According to the program description, “Their research shows that climate change has very little connection with the so-called greenhouse effect, and in fact is almost exclusively controlled by solar, atmospheric pressure, and gravitational factors that are beyond man’s ability to control.” 
August 4, 2017
The Coloradoan reported that Ned Nikolov and his colleague Karl Zeller have been pushing to promote the view that greenhouse gas emissions by humans are not to blame for global warming, but rather solar radiation and atmospheric pressure. 
According to the paper, they have gone as far as to publish under pseudonyms because “they’ve had a hard time getting the scientific world to hear them out, let alone take them seriously.” 
Atmospheric scientist Scott Denning of Colorado State University said that the model developed by Nikolov and Zeller was “too simple,” did not adequately take into account thermodynamics, and the larger issue of “leaping to the conclusion that there is no greenhouse effect based on the model,” the Coloradoan reported. 
Zeller and Nikolov argue that Denning did not properly understand their work, and challenge critics to find an error in their work: 
“After honestly reading the paper and taking the time to understand the terms, the data, the math and the gas physics, please document one significant error in the data, or the math, or the physics and allow us to explain it,” Zeller wrote. 
After being rejected, the two changed the spelling of their names. Karl Zeller took on the pseudonym Lark ReLlez while Ned Nikolov became Den Volokin. “We thought in order to give the reviewers an opportunity to only focus on the content of the paper and not be distracted by anything else, we have to hide our identities,” Nikolov said. 
While initially accepted, Nikolov claimed that it was later retracted because of their use of pseudonyms. NASA research Gavin A. Schmidt, who had alerted Retraction Watch to the paper’s withdrawal, tweeted: 
Top tip for climate contrarians: When you submit nonsense papers to journals, spell your name backwards so no-one knows who you are.
— Gavin Schmidt (@ClimateOfGavin) September 12, 2016
Nikolov and Zeller publish a paper in a new “open access” journal called “Environment Pollution and Climate Change” launched by an Indian publisher which subsequently faced multiple charges of deception from the Federal Trade Commission relating to the company’s claims of peer review and marketing practices. The journal was at the time edited by an advisor to the Heartland Institute, Dr Arthur Viterito.
The paper – The Refutation of the Climate Greenhouse Theory and a Proposal for a Hopeful Alternative – suggested the well-established theory of greenhouse warming was fatally flawed. Professor Steve Sherwood, the director of the Climate Change Research Center at the University of New South Wales in Australia, reviewed the paper and told DeSmog:
“The paper is laughable. It is so riddled with unsupported, fantastic and … or … unintelligible claims, arranged in a disorderly fashion and sprinkled liberally with innuendo.”
Referring to the journal and several papers it had published, Professor Michael Mann, a climate scientist at Penn State University and a vocal opponent of climate science denial, told DeSmog: “This isn’t science. It’s politically motivated denialist garbage.”
He added: “Such sham journals make a mockery of the scientific process and must be exposed for what they are. Associating in any way with this pseudo-journal would endanger one’s scientific reputation. Keep your distance from this toxic mess.”
In 2014, Zeller and Nikolov published in the journal SpringerLink an article titled “On the average temperature of airless spherical bodies and the magnitude of Earth’s atmospheric thermal effect,” under the names “Den Volokin” and “Lark ReLlez.” 
A later erratum, published in December 2016, included a statement by the authors on their use of pseudonyms, claiming it was “necessary to guarantee a double-blind peer review of our manuscript”: 
“Erratum to: SpringerPlus (2014) 3:723 DOI 10.1186/2193-1801-3-723
As authors of this article (Volokin and ReLlez 2014) we would like to clarify that our real names are Ned Nikolov and Karl Zeller. We created the pseudonyms Den Volokin and Lark ReLlez by spelling our names backward. Ned Nikolov is a physical scientist with the USDA Forest Service; he had been instructed by his employer not to engage in climate research during government work hours, nor to reveal his government affiliation when presenting results from his climate studies. Karl Zeller is a retired USDA Forest Service research scientist with no restrictions. Ned Nikolov worked on this manuscript outside of his assigned official work duty hours. Because of the controversial subject matter and the novel findings previously associated with Nikolov and Zeller, we felt that the use of pseudonyms was necessary to guarantee a double-blind peer review of our manuscript and to assure a fair and unbiased assessment. We are sorry for any inconvenience this may have caused the Editorial Board and the readership of SpringerPlus.”
Even climate change skeptic Anthony Watts criticized the two for their actions. In an article titled “Climate Skeptics Behaving Badly,” Watts wrote “Submitting a paper with your names reversed? I’m sorry… This. is. just. stupid” (emphasis Watts’). 
August 18, 2015
Nikolov and Zeller co-published a paper titled “Emergent model for predicting the average surface temperature of rocky planets with diverse atmospheres” under pseudonyms “Den Volokin” and “Lark ReLlez”—Nikolov and Zeller’s name spelled backwards. The paper was withdrawn. 
According to Retraction Watch, the notice doesn’t state the precise reason for withdrawal. Elsevier, which publishes Advances in Space Research, confirmed that the paper was withdrawn due to an “authorship issue”— that being, presumably, that the authors had used pseudonyms. 
The blog …and Then There’s Physics also commented on a following version of the retracted paper, writing that “we can be very confident that Nikolov and Zeller’s argument that planetary surface temperature is set by pressure alone is wrong.” 
- USDA Forestry Service — Former Meteorologist. 
- Environmental Protection Agency — Worked in “the fields of meteorology and air pollution,” although CV does not specify further. 
- The Bureau of Land Management — Worked in “the fields of meteorology and air pollution,” although CV does not specify further. 
- USAF — Reservist Weather Forecaster. 
- Karl Zeller does not appear to be active on social media.
- “New insights on the physical nature of the atmospheric greenhouse effect deduced from an empirical planetary temperature model,” Environmental Pollution and Climate Change, 2017.
- Ned Nikolov and Karl Zeller. “On the average temperature of airless spherical bodies and the magnitude of Earth’s atmospheric thermal effect,” SpringerPlus, 2014.
- “Karl Zeller,” ResearchGate. Accessed February 18, 2018.
- “Short BioKARL F. ZELLER, Ph. D., Col (USAF Ret.),” Retrieved from ScribD. Uploaded by user “republicfortheunitedstates” on September 7, 2017.
- Ben Guarino. “Scientists published climate research under fake names. Then they were caught,” The Washington Post, September 19, 2016. Archive.is URL: http://archive.is/0X80d
- Kevin Duggan.”Fort Collins scientists struggle to air alternative view on climate change,” The Coloradoan, August 4, 2017. Webcite URL: http://www.webcitation.org/6xI3QpcCx
- “CHALLENGING THE GREENHOUSE THEORY – SCIENTISTS NED NIKOLOV AND KARL ZELLER,” Republic for the United States of America, September 8, 2017. Archived February 18, 2018. Archived .mp3 on file at DeSmog. Archive.is URL: https://archive.is/ITWLR
- Kevin Duggan. “Fort Collins scientists struggle to air alternative view on climate change,” Coloradoan, August 4, 2017. Webcite URL: http://www.webcitation.org/6xI3QpcCx
- Graham Readfearn. “Exclusive: UN, EU Agencies Reject Ties to Conference Hijacked by Climate Science Deniers,” DeSmog, May 31, 2017.
- “IT‘S TIME TO PROSECUTE THE CLIMATE FRAUDSTERS,” WND, December 6, 2015. Archive.is URL: https://archive.is/xPMvf
- “Top tip for climate contrarians: When you submit nonsense papers to journals, spell your name backwards so no-one knows who you are,” Twitter post by user @ClimateOfGavin, Septembe 12, 2016. Archived .png on file at DeSmog.
- Den Volokin and Lark ReLlez. “On the average temperature of airless spherical bodies and the magnitude of Earth’s atmospheric thermal effect,” SpringerPlus, 2014 3:723. Archived February 18, 2018.
- Ned Nikolov and Karl Zeller. “Erratum to: On the average temperature of airless spherical bodies and the magnitude of Earth’s atmospheric thermal effect,” SpringerPlus 2016 5:2085. Archived February 18, 2018.
- Anthony Watts. “Climate Skeptics Behaving Badly,” Watts Up With That? September 14, 2016. Archived February 19, 2018. Archive.is URL: https://archive.is/tMyCy
- Den Volokin and Lark ReLlez. “WITHDRAWN: Emergent model for predicting the average surface temperature of rocky planets with diverse atmospheres,” Advances in Space Research, August 18, 2015.
- “U.S. gov’t researchers withdraw climate paper after using pseudonyms,” Retraction Watch, September 13, 2016. Archived February 16, 2018. Archive.is URL: https://archive.is/kwb3t
- “No, pressure alone does not define surface temperatures!” …and Then There’s Physics, August 8, 2017. Archived February 16, 2018. Archive.is URL: https://archive.is/3X5F0
- “Karl Zeller,” United States Department of Agriculture. Archived April 14, 2016. Archive.is URL: https://archive.is/i3J52
- “Karl Zeller,” United States Department of Agriculture. Archived February 16, 2018. Archive.is URL: https://archive.is/bK61b
- “Making the Elephant Dance as Performed by Ned Nikolov and Karl Zeller,” Rabett Run, August 7, 2017.