Congress members got the chance to question oil executives about their role in spreading disinformation about climate change for the first time ever on Thursday during an all-day House Oversight Committee hearing.

The hearing is being compared to a similar event in 1994 when the top executives of American tobacco companies spoke to Congress about the dangers of smoking. At that hearing, the executives claimed that smoking is not addictive but admitted that it can be harmful.

Similarly, the oil executives at the October 28 hearing acknowledged that climate change exists and that humans are making the issue worse, but still avoided fully exposing their efforts to allegedly mislead the public.

"I had hoped today would be a turning point for the oil industry," committee chair Rep. Carolyn Maloney said. "I was grateful to hear the top fossil fuel CEOs finally admit that climate change is real, that burning fossil fuels is causing it, and that we must act urgently to fix it. But I was disappointed we also heard much of the same denial and deflection we have heard before."

Prior to the hearing, the committee requested that oil companies provide documentation showing their efforts relating to climate change. Rather than providing that information, the companies largely gave information that is already publicly available on their websites. At the end of the hearing, Maloney issued a subpoena for the relevant documents.

"We are at code red for climate and I committed to doing everything I can to help rescue this planet and save it for our children," Maloney said during her closing remarks. "We need to get to the bottom of the oil industry's disinformation campaign, and with these subpoenas we will."

The subpoenas call on executives to produce "detailed funding information" including documentation of "payments to shadow groups" and other firms. The companies must also turn over internal communications from senior executives regarding climate change and the company's role in causing the issue.

"I have tried very hard to obtain this information voluntarily, but the oil companies employ the same tactics they used for decades on climate policy: delay and obstruction," Maloney said.

Issuing the subpoenas was not the original plan, according to Rep. Ro Khanna, D-CA. The decision to do so was reportedly made just 30 minutes before the end of the hearing.

"We're very cautious to issue a subpoena, and we hadn't issued any subpoenas up until now," Khanna told CNN.

Khanna says that the investigation process could take six months, and that the executive may be called before Congress a second time. The investigation has been underway for roughly three months.

During that investigation, it was revealed that ExxonMobil (XOM  ) "aggressively" fought against climate action and science in recent times, despite the fact that Exxon's own scientists knew about the role of fossil fuels in climate change as far back as the 1970s.

"Our witnesses today would like you to think that their actions I have laid out and put in the record are ancient history, but they're not," Maloney said.

Khanna shamed the executives regarding their climate change efforts in comparison to those seen in other countries.

"Are you embarrassed as an American company that your production is going up while European counterparts are going down?" Khanna asked Chevron (CVX  ) CEO Michael Wirth.

Wirth defended his company by pointing out the growing demand for energy around the world. Wirth said that he is "very proud of our company and what we do."

Several Congress members called on executives to resign from their positions, citing their history of propagating disinformation. While the disinformation may not have had the companies' names attached, companies allegedly use front groups to lobby against climate action.

"When you look at these ads, they don't say the name 'Exxon,' 'BP' (BP  ), 'Chevron' anywhere," Rep. Rashida Tlaib, D-MI, said. "Y'all hide and you deceive the public."

Meanwhile, several Republicans on the committee took the chance to thank the executives for their continued production of oil while claiming that Democrats were abusing their power.

"It's abhorrent my colleagues across the aisle have called a so-called hearing today to demonize American industry whose products make modern life possible," Rep. Clay Higgins, R-LA, said.

Later he added, "It's insane what my colleagues across the aisle are putting these good American men and women through and attacking American workers as our country dissolves around us. You push patriots too far; you've gone a bridge too far. We won't take it anymore."

The residents of Higgins' state are among the most vulnerable in the entire country to flooding caused by climate change.

As for the oil executives, no one admitted to spreading disinformation in public statements. When the executives were asked if any of them would commit their company to stop anti-climate action lobbying, none responded.