The lone witness called by the GOP minority, Lord Christopher Monckton, a leading climate skeptic, called the data used by the IPCC "bogus," adding that the global increase in carbon dioxide emissions is "naturally caused."
"Therefore, the correct policy is to have the courage to do nothing," Monckton told the committee. "You will lose nothing thereby. There are many other problems to address. I would recommend those and not this."
Monckton is a conservative British journalist and former adviser to Margaret Thatcher whose is critical of government actions to prevent climate change. He does not have a scientific background.
The decision to let Monckton testify outraged Rep. Jay Inslee (D-Wash.), who said the fact that the GOP "couldn't produce one scientist to deny this clear consensus...says a lot about the status of this debate, which we should not be having."
Rep. Earl Blumenauer (D-Oregon) had similarly harsh words for Monckton.
"I find it a little embarrassing and sad that the minority's witness is a journalist with no scientific training, who didn't come here with any information against the science," said Blumenauer. "It's entertaining but...there's nothing here that contradicts the basic science."
Hacked Emails: 'Tempest in the Teapot'
Blumenauer also reminded the committee that formal inquiries in the U.S. and Britain have cleared researchers involved in the hacked email dispute at the University of East Anglia Climactic Research Unit (CRU) of any scientific misconduct.
The results reveal that the controversy is a "tempest in the tea pot," Blumenauer said.
The scandal blew up late last year when thousands of private emails were stolen from a University of East Anglia server and placed on the Internet. Critics say the correspondence reveals attempts by scientists to fend off freedom of information (FOI) requests for primary temperature data and computer codes, leading to accusations that researchers violated the UK's .
Skeptics continue to seize on the emails as evidence that warming is not real.
In February, a Penn State University panel that was formed to investigate climatologist Michael Mann, a prominent member of the faculty there and recipient of around 300 of the hacked emails, the researcher of all wrongdoing.
Similarly, an examination by the British House of Commons into CRU director Phil Jones no unethical behavior on the part of Jones and "no reason" to challenge the scientific consensus. And last month, a panel convened by the University of East Anglia and led by Lord Ronald Oxburgh, the former chair of the House of Lords science and technology select committee, that there was "no evidence of any deliberate scientific malpractice in any of the work."
Lisa Graumlich, director of the School of Natural Resources and the Environment at the University of Arizona and member of the Oxburgh panel, told Congress on Thursday that "if [scientific malpractice] had been there, we believe we would have detected it."
With the scientific consensus now sufficiently clear, "the urgency to act is very much upon us," Graumlich said.
Chairman Ed Markey (D-Mass.), a principal author of the American Clean Energy and Security Act that slipped through the House last June, said "time is of the essence" on passing a climate change bill in the United States.
The hearing on Thursday was held as engineers battled to stop the calamitous BP oil spill in the Gulf of Mexico and as Sens. John Kerry (D-Mass.) and Joseph Lieberman (I-Conn.) prepared to introduce their stalled climate and energy bill next week.