Scientists who doubt climate change are akin to Galileo, the scientist who was put under house arrest for finding the Earth rotates around the sun, according to Texas Sen. Ted Cruz.

The Republican presidential candidate compared the scientists agreeing with global warming to the persecution of Galileo for his findings that the Earth moves around the sun.

"In 1615, I suspect, if you asked, 97 percent of scientists at the time would have said the sun rotates around the Earth," Cruz said.

"I would note it was the Roman Inquisition that brought heretics before it who dared say the Earth revolved around the sun and today the global warming alarmists have taken the language of the Roman Inquisition."

Cruz currently ranks first in the Washington Examiner's presidential power rankings.

The hearing, "Data or Dogma? Promoting Open Inquiry in the Debate over the Magnitude of Human Impact on Earth's Climate," featured three scientists who said the mainstream scientific community ostracized them for their views on climate change.

The scientists who doubt climate change, or doubt the impact mankind is having on climate change, discussed their doubts about mainstream data that led to their beliefs. They also called into question computer models that the government has used to form regulations, such as the Clean Power Plan.

"There is really no way to prove why the climate does what it does," said John Christy, professor of atmospheric science and director of the Earth System Science Center at the University of Alabama-Huntsville.

Christy said climate change-doubting scientists have difficulty getting funding because their views are outside the norm. That leads to no check on climate science and that can lead to regulation like the Clean Power Plan, which he believes is faulty.

"This happens when the scientific process that allegedly underpins regulation lacks objectivity and transparency," he said.

Sen. Gary Peters, D-Mich., said the views of climate change doubting-scientists should be respected but their beliefs shouldn't keep the government from acting on climate change.

"Knowing that there is more to learn should not, should not, stop us from acting on what we know," he said.

Despite Cruz calling the hearing, only one other Republican senator attended.

Instead, many of the senators who came to the meeting were Democrats who mainly asked questions of David Titley, a retired rear admiral who now is a professor of practice in the Department of Meteorology at Pennsylvania State University.

Titley said his investigations into climate change showed air temperatures are increasing, ocean temperatures are increasing, sea levels are increasing, glaciers are retreating and oceans are acidifying.

The science around climate change isn't perfect, Titley said, and there are temperature blips going both up and down on a short- and medium-term basis. However, the long-term trend shows an increase in global temperatures that he believes needs to be acted upon.

"In the military, you don't always have perfect information. In fact, you hardly ever have perfect information, but you act on what you know," Titley said.

"If you wait for 100 percent certainty on the battlefield, you'll probably be dead. Let's not do that."

The senators were not the only ones asking questions during the nearly three-hour long hearing.

In an unusual moment, Judith Curry, chairwoman of the School of Earth and Atmospheric Science at the Georgia Institute of Technology, and author Mark Steyn turned the tables on Sen. Ed Markey, D-Mass., and began asking the senator questions about climate science. The questioning went on for minutes uninterrupted by subcommittee chairman Cruz.

Steyn could often be heard making dismissive noises while Markey and other Democratic senators spoke, since he left his microphone on for most of the hearing. He often jumped in to ask questions of other senators or request Cruz allow him or another witness to respond to something said during a senator's statement.

"We are talking about the greatest shift in the global economy that has ever been contemplated," Steyn said of the Clean Power Plan. "We talk about risk management, well, this is a helluva risk."