Dive Brief:

• Oklahoma Attorney General Scott Pruitt (R), President-elect Donald Trump's pick to lead the Environmental Protection Agency (EPA), told Senate lawmakers his personal opinion of climate change is "immaterial" because the EPA "has an obligation" regulate carbon under the Clean Air Act. 
• During his confirmation hearing, Pruitt acknowledged that climate change is real but told members of the Senate Environment and Public Works Committee that the ability to measure human impact on the climate is "subject to continued debate and dialogue."
• Pruitt also affirmed EPA's authority to regulate mercury under the Act, though he challenged agency rules on it and other pollutants during his time as Oklahoma AG. Those lawsuits were not questioning the importance of regulating harmful emissions, Pruitt said, but rather challenging overreaches of federal authority.  

Dive Insight:

At the halfway point of the Pruitt confirmation hearings, there are two general ways to view the nominee. 

Critics say Pruitt favors industry over environmental protection, pointing to extensive ties with fossil fuel companies and more than a dozen lawsuits Pruitt filed against Obama's EPA during his time in Oklahoma. 

But Pruitt and his allies say those lawsuits were about federalism — the concept of government in which states share power with the federal government — not aimed at weakening environmental and health regulations specifically. Pruitt said challenges to the EPA's Mercury and Air Toxics Standards, Cross State Air Pollution Rule and other regulations were more about ensuring the EPA followed the "rule of law" in setting regulations. 

Pruitt's logic extends to the Clean Power Plan and regulating carbon. While the EPA overstepped its bounds in promulgating the nation's first set of CO2 rules for existing power plants, Pruitt said the current legal interpretation of the Clean Air Act requires the agency to do something to address carbon. 

"I believe the EPA under the Mass. v EPA case and the endangerment finding, has an obligation to address the CO2 issue," he told lawmakers, "but in doing so they need to follow the processes set out by Congress."

In that case, the Supreme Court rejected an industry challenge to the EPA's 2009 endangerment finding, which found CO2 to be a pollutant under the Clean Air Act. In effect, it means the EPA would have to issue a new rule to regulate CO2 if it repealed the Clean Power Plan, which the president-elect has promised. 

Pruitt's acknowledgement of the EPA's authority over carbon will come as a relief to environmentalists who feared he could threaten the endangerment finding. Though lawyers say undoing it would be exceedingly difficult, Pruitt joined 14 other attorneys general in a 2012 court challenge to the endangerment finding, which was eventually thrown out by the D.C. Circuit Court. 

The carbon authority comment came amid heated exchanges over the causes of climate change. While Pruitt said he believes climate change exists, he said there are still questions over how much humans contribute to the warming. 

Mainstream climate scientists say that stance obfuscates the consensus view. While uncertainty always exists, the United Nations Intergovernmental Panel on Climate Change holds that it is "extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century."

Sen. Bernie Sanders (I-VT) pressed Pruitt on the point, asking him if he believed climate science means the U.S. must "transform its energy system away from fossil fuels" 

Pruitt demurred, saying his personal opinion of climate policy was "immaterial to the job," before adding again that the EPA "has a very important role in regulating carbon." 

Just how a Pruitt-led EPA would go about that remains an open question, and not one senator has yet asked. The hearing returns at 1:45 EST and can be streamed here.