Scott Pruitt, Donald Trump's pick to head the Environmental Protection Agency, on Wednesday said he did not agree with the president-elect's past suggestion that climate change is a hoax.
The Oklahoma attorney general was grilled over his views on climate change by Democrats on the Senate Environment and Public Works Committee during his confirmation hearing.
Pruitt has faced stiff opposition from Democrats and environmentalists because he has raised doubts about humans' role in climate change and has been party to more than a dozen legal challenges to President Barack Obama's climate change efforts.
In 2012, Trump suggested on Twitter that climate change was a hoax created by the Chinese in order to make U.S. manufacturing less competitive. He later said the tweet was a joke, and during a debate with Hillary Clinton, denied ever having said it.
Asked by Sens. Edward Markey and Bernie Sanders about the tweet, Pruitt said he did not agree with the view Trump expressed at the time.
In his opening statement, Pruitt said, "Science tells us that the climate is changing and that human activity in some manner impacts that change."
"The ability to measure with precision the degree and extent of that impact and what to do about it are subject to continuing debate and dialogue, and well it should be," he added.
The overwhelming majority of the scientific community believes in global warming and that humans play a significant role.
Democratic Sen. Thomas Carper also asked Pruitt about Trump's assertion during the campaign that his administration would "get rid" of the EPA "in almost every form," and that only "tidbits" of the agency would survive.
Pruitt said he believes there is a very important role for the EPA, particularly in handling air and water quality issues across state lines.
"The EPA has served a very valuable role historically," he said.
Pruitt is seen as an ideal candidate to carry out Trump's anti-regulation agenda. He describes himself as "a leading advocate against the EPA's activist agenda" and established a "federalism unit" in Oklahoma to "combat unwarranted regulation and overreach by the federal government."
On Wednesday, Pruitt laid out the principles that would guide him as EPA administrator. He stressed following the rule of law so companies know how they will be regulated and partnering with state regulators to set policy.
Pruitt said he believes it's necessary to restore confidence and certainty in those that are regulated by the EPA. He said it had become difficult for companies to predict what is expected of them under environmental laws.
In recent years, Pruitt took a leading role in coordinated efforts by Republican state attorneys general and energy companies to challenge Obama's initiatives to mitigate climate change and pollution through executive action.
If Pruitt is confirmed, he will be in the position of defending the agency against legal challenges that he himself helped bring.
On Wednesday, he declined to say he would recuse himself from handling these cases to avoid the appearance of a conflict of interest. Instead, he said he would consult the EPA's ethics counsel and distance himself from the cases if and when the agency's lawyers advise him to do so.
The Republican Attorneys General Association and energy companies contend the EPA, under Obama, is guilty of executive overreach and has hurt business.
Environmentalists counter that the Republican attorneys general are serving the energy industry's interests at the expense of public health and the environment. They point to the millions of dollars fossil fuel companies have contributed to the GOP attorneys general group, its nonprofit arm and individual members.
Energy companies that litigated against the EPA alongside Pruitt contributed nearly $240,000 to his campaign or political action committees that supported him between 2010 and 2016, according to the Environmental Working Group, a research and advocacy nonprofit.
Grilled by Democratic Sen. Sheldon Whitehouse of Rhode Island about such contributions, Pruitt acknowledged that his re-election committee had received contributions from energy interests such as Devon Energy, Koch Industries and Exxon Mobil.
However, he said he was unsure whether they gave the maximum contribution and was uncertain about energy company donations to his political action committees.
Correction: Sen. Sheldon Whitehouse questioned Pruitt about energy company contributions. An earlier version misidentified the senator.