(Bloomberg) -- Interior Secretary-designate Deb Haaland pledged to “strike the right balance” in managing hundreds of millions of acres of federal land during a confirmation hearing Tuesday, as she sought to reassure senators worried she would clamp down on fossil fuel development.

Under questioning from Senator Joe Manchin, the Democrat from coal-rich West Virginia who leads the committee vetting her nomination, Haaland emphasized that a clean energy transition is “not going to happen overnight,” and the U.S. will continue to rely on fossil fuels, even as the country advances technology and innovation.

The federal government should continue permitting oil wells, pipelines and coal mines, Haaland said. “The earth is here to provide for us,” she told the Senate Energy and Natural Resources Committee.

“There’s no question that fossil energy does and will continue to play a major role in America for years to come,” and the activity helps fund “critical services,” Haaland said. “But we must also recognize that the energy industry is innovating, and our climate challenge must be addressed. Together we can work to position our nation and all of its people for success.”

Several Senate Republicans have already signaled opposition to Haaland’s candidacy to lead the Interior Department, arguing that her opposition to fracking and endorsement of the Green New Deal make her unfit for a job that includes overseeing energy development on federal land. Senator John Barrasso of Wyoming, the energy committee’s top Republican, has criticized what he called Haaland’s “radical views.”

Manchin, who plays a critical role in the narrowly divided Senate and has already promised to vote against confirming Neera Tanden to be budget director, is still undecided on Haaland. On Tuesday, he asked tough questions of her commitment to energy development and her approach to the reclamation of abandoned coal mines, but he also emphasized that President Joe Biden should have wide deference in filling his cabinet.

“As a former governor, I have always believed that a president should be given wide latitude in the selection of his cabinet,” Manchin said. “I also take the Senate’s constitutional obligation to advise and consent to the president’s nominations seriously.”

Barrasso said he believed Haaland’s positions are “squarely at odds with the mission of the Department of Interior,” including “managing the nation’s oil, gas and coal resources in a responsible manner, not eliminating access to them.”

“If Representative Haaland intends to use the Department of Interior to crush the economy of Wyoming and other wester states, then I’m going to oppose the nomination,” Barrasso warned.

The Interior Department has a wide reach across the U.S., with decisions affecting grazing, hunting, recreation, energy development and other activities on about a fifth of U.S. land, some 700 million subsurface acres of minerals and 2.5 billion acres of the outer continental shelf. The agency also oversees more than 400 national parks, 100 national monuments and 500 wildlife refuges as well as nearly 1,000 dams and reservoirs that supply water to 31 million people. The department’s Bureau of Indian Affairs also works directly with 578 federally recognized tribes.

Manchin emphasized the broad scope of the Interior secretary’s role as the guardian of the nation’s public lands but also its energy production.

Lands and waters managed by the Interior Department produce nearly 20% of the nation’s energy “that is critical for our energy independence,” Manchin said, including 12% of its natural gas, 24% of its oil and 43% of its coal.

Haaland, who is a member of the Laguna Pueblo tribe west of Albuquerque, New Mexico, would become the first Native American cabinet secretary. Biden nominated Haaland after a months-long campaign by Native Americans and environmental activists, who have said she would reset the Interior Department’s relationship with tribal nations and would bring a fresh perspective to the agency most frequently led by White, male Western politicians.

Haaland, 60, was just re-elected to her second term as a Democrat representing New Mexico in the U.S. House of Representatives.

Haaland, a single mother who at times relied on food assistance, emphasized Tuesday she is “not a stranger to the struggles many families across America face today,” having “lived most of my adult life paycheck to paycheck.”

“I carry my life experiences with me everywhere I go,” Haaland told the energy committee. “It’s those experiences that give me hope for the future. If an indigenous woman from humble beginnings can be confirmed as secretary of the interior, our country holds promise for everyone.”

Haaland was a tribal administrator of the San Felipe Pueblo as well as the operator of a small salsa-making business. She’s represented New Mexico in the U.S. House since 2019.

Haaland pledged to seek balance at Interior. “If confirmed,” she said, “I will work my heart out for everyone -- the families of fossil fuel workers who help build our country, ranchers and farmers who care deeply for their lands, communities with legacies of toxic pollution and people of color whose stories deserve to be heard.”

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