Donald Trump's choice for secretary of state says climate change does exist and the risk is great enough to warrant action.
Exxon Mobil CEO Rex Tillerson didn't say what action.
Tillerson told the Senate Foreign Relations Committee Wednesday the increase in greenhouse gases is "having an effect." But he says the "ability to predict that effect is very limited."
The president elect has sent mixed signals on climate change. He has brushed it off as a Chinese hoax and also said "nobody really knows."
Tillerson says he came to his personal position on climate change as a scientist. He says Trump has invited his thoughts on the contentious subject. "I feel free to express those views," he says.
Tillerson also says he would recuse himself as secretary of state from matters that involve Exxon Mobil.
Donald Trump's choice to be secretary of state says he's not had a conversation with the president-elect about U.S. policy toward Russia.
Tillerson's statement to the Senate Foreign Relations Committee came despite the intense focus members of Congress have had on Russia over allegations Moscow meddled in the 2016 election to help Trump win.
Tillerson says he favors keeping the current sanctions against Russia in place until the Trump administration takes office.
"I would leave things in the status quo so we can convey it could go either way," Tillerson says.
Tillerson also says Russia's targeted bombing in the Syrian city of Aleppo "is not acceptable behavior" but he's declining to flatly say that Moscow is guilty of war crimes. He says he'll wait until he sees detailed intelligence before making that decision.