WASHINGTON – President Donald Trump’s nominee to be United Nations ambassador publicly broke with the White House over climate change on Wednesday, calling it a "real risk" and promising to take the issue seriously if confirmed to the high-profile diplomatic position.

The statement by Kelly Knight Craft – made during a contentious Senate confirmation hearing – marked a sharp reversal from her previous comments, in which she said she believed "both sides" of the science on climate change.

"Climate change needs to be addressed as it poses real risk to our planet," Craft, who is currently the U.S. ambassador to Canada, said in opening remarks before the Senate Foreign Relations Committee.

"Let there be no doubt" that human behavior is contributing to global warming, she added. "I will be an advocate in addressing climate change," Craft promised, although she also said the United States should not shoulder an "out-sized burden" in curbing greenhouse gas emissions.

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Craft's statement was particularly remarkable because of her family ties to the coal industry and because Trump has claimed that global warming is "a hoax" perpetrated by China.

Craft's coal connections

Craft is a top Republican donor from Kentucky, and her billionaire husband, Joseph Craft III, is the president and CEO of Alliance Resource Partners, a major U.S. coal company. Trump tapped Craft for the U.N. post at the urging of Senate Majority Leader Mitch McConnell, R-Ky.

Craft and her husband donated $1 million to Trump’s inauguration in 2016, according to the Center for Responsive Politics, a nonpartisan group that tracks money in politics. The center’s data show that Alliance Resource Partners, through its employees and other associated entities, have donated more than $5 million to federal candidates since 2010 – almost exclusively to Republicans, including several GOP members of the Foreign Relations Committee.

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Campaign donors are often rewarded with plum ambassador posts. And Craft’s supporters say she is well qualified for the job, pointing in part to her tenure in Canada, where she helped navigate the contentious trade negotiations that led to a new agreement to replace NAFTA.

McConnell introduced Craft at Wednesday's hearing, calling her a distinguished stateswoman and leader who has "the knowledge, talent, and experience" to represent the U.S. at the United Nations.

Controversial climate change comment

It's not clear if Craft's reversal on climate change will be enough to assuage Senate Democrats, who sharply questioned her commitment to confronting an issue that tops the United Nations' agenda.

Craft sparked ridicule and outrage when she claimed to believe scientists on “both sides” of the climate change debate during a 2017 interview with Canada’s CBC television network.

“I believe there are scientists on both sides that are accurate,” Craft said when asked if she believed in climate change.

Pressed on whether she believes humans are not contributing to climate change, she said then: “Well, I think that both sides have, you know, their own results from their studies, and I appreciate and respect both sides of the science.”

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The overwhelming majority of scientists have concluded that climate change is a growing threat as a result of human activities. The United Nations has called climate change "the defining issue of our time" as extreme weather, rising sea levels and other problems unfold across the globe.

Before Wednesday's hearing, three Senate Democrats highlighted Craft's financial holdings in the fossil fuel industry and pressed her for any documents that show how international agreements to address climate change could impact her family’s assets.

“Your financial disclosures show that you personally have over $63 million invested in oil, gas and coal assets,” Sens. Edward Markey, D-Mass.; Jeffrey Merkley, D-Ore.; and Sheldon Whitehouse, D-R.I., wrote in a recent letter to Craft.

Craft’s work schedule in Canada

Democrats also raised questions about a report in Politico suggesting that Craft was often absent from her post as the top American diplomat in Ottawa. The news outlet said she frequently used her husband’s private jet to return to the U.S. during a 15-month stint as U.S. ambassador to Canada.

Citing an unnamed source, the story said Craft was known as the “absent ambassador” inside the State Department.

"You were away more than 300 days from" that post, Sen. Robert Menenedez, D-N.J., said during Wednesday's hearing.

"I find this staggering amount of time away from post very troubling and an abdication of leadership," he said, noting that if confirmed, she will be serving with "some of the most experienced, seasoned, and sometimes ruthless diplomats from all over the world."

Republicans on the panel defended Craft over her time away from Ottawa, noting that part of it was spent in Washington attending negotiations over the new trade agreement between the U.S., Mexico, and Canada.

Sen. Marco Rubio, R-Fla., noted that she had personally paid for all her trips, thus saving U.S. taxpayer dollars even when she was traveling on official business. And Sen. Ted Cruz, R-Texas, noted that some of her trips were not back to the U.S. but to other parts of Canada.

Wednesday’s hearing comes more than six months after Trump’s first U.N. ambassador, Nikki Haley, left the administration. Trump initially tapped Heather Nauert, a former Fox News host and State Department spokeswoman, to replace Haley. But Nauert withdrew amid questions about her qualifications for the high-profile position.