US Secretary of the Interior Department Ryan Zinke has claimed on multiple occasions that he is a geologist, despite the fact he has never worked as one.

Last week, Zinke used his "scientific expertise" to defend the shrinking of Bear Ears national monument after emails revealed that the decision was based on oil exploration.

"I'm a geologist," he said.

"I can assure you that oil and gas in Bears Ears was not part of my decision matrix. A geologist will tell you there is little, if any, oil and gas."

This is one of Zinke's favorite claims. CNN reports that since becoming Secretary of the Interior, Zinke has publicly called himself a geologist or a former geologist at least 40 times, including a few times under oath before Congress.

And just like the recent incident with Bears Ears, Zinke often uses this tactic to boost support for his policies.

Defending his decision to exempt the state of Florida from offshore drilling, Zinke told Breitbart News in what has to be the most vague, scientific statement ever: "Florida is different in the currents — I'm a geologist — it's different in geology."

Attacking the US Geological survey at a press conference, Zinke said: "I think the assessments of the USGS has done previous, I think they fall short, from a geologist's point of view."

Under oath in front of the House Natural Resources Committee last month, Zinke said, "I can tell you, from a geologist, offshore mining of sand is enormously destructive environmentally, as in comparison to seismic."

Now, is probably a good time to clarify that Zinke has never worked as a geologist. Even Zinke's autobiography and his LinkedIn fail to mention any work that he has done as a geologist.

In fact, it seems the only evidence for Zinke's claims is an undergraduate degree in geology that he got 34 years ago from the University of Oregon.

In his autobiography, Zinke describes how he picked his major.

"I studied geology as a result of closing my eyes and randomly pointing to a major from the academic catalog, and I never looked back. I am just glad I did not find electronics," he wrote.

Many scientists have taken offense to Zinke's self-proclaimed expertise. They argue that someone with a 34-year-old degree who has never worked in the field cannot be considered a geologist.

"He seems not to be familiar with modern geologic knowledge," said Seth Stein, a professor at the Department of Earth and Planetary Sciences at Northwestern University.

"In particular, geologists now know that the climate is warming rapidly because of human activities. This is is causing many serious problems including rising sea level, which is a major threat to coastal communities."

Zinke, on the other hand, has denied the primary role that humans play in climate change.

"It's not a hoax, but it's not proven science either," said Zinke when speaking about climate change on the Montana Television Network.

"But you don't dismantle America's power and energy on a maybe. We need to be energy independent first. We need to do it better, which we can, but it is not a settled science."

Career geologist, Jess Phoenix, who is running for Congress in California, was particularly incensed by Zinke's gumption.

"I'm a geologist," said Zinke, during a Senate Appropriations meeting last June.

"And I don't consider myself a genius, but I'm a pretty smart guy."