(Sarah Parnass/The Washington Post)

President-elect Donald Trump’s pick to lead the Interior Department told senators Tuesday that completing billions of dollars in backlogged projects at national parks should be a major part of the new president’s plans to revamp aging roads, bridges and transportation hubs.

Rep. Ryan Zinke (R-Mont.), who is nominated to serve as the next interior secretary, told the Senate Natural Resources Committee that Trump’s ambitious infrastructure spending plans should “prioritize the estimated $12.5 billion in backlog of maintenance and repair” at hundreds of national parks across the country.

Zinke also said publicly for the first time that unlike Trump, he doesn’t believe climate change is a hoax. Answering pointed questions on the issue from Sen. Bernie Sanders (I-Vt.), Zinke said humans are almost certainly the drivers of climate change, but he said there’s a debate among scientists over how much.

Sanders interrupted, saying there’s no debate in the scientific community, only on his committee. Zinke said it’s a matter that he will study with deliberation as secretary. Zinke’s comments Tuesday provided his clearest perspective on one of the most contentious issues in politics. He seemed to flip-flop in his approach in previous years.

Rex Tillerson, Trump’s choice to serve as secretary of state, also said last week that climate change is affected by humans and is not a hoax.

“Man has had an influence,” Zinke said under questioning by Sanders.

On the question of repairing the parks, Zinke said Trump “is committed to a jobs and infrastructure bill, and I am committed and need your help in making sure that bill includes our national treasures.”

He said repair projects should include fixing sewers and restrooms at parks in the West, finding ways to develop land just outside national parks — and even fixing fountains on federal property in downtown Washington.

During a recent visit to the Trump transition team’s offices on F St. NW in Washington, Zinke said he was shocked to see unresolved repairs at a federal park across the street.

“The fountains don’t even work. And they’re in need of repair,” he told senators. “And then you start asking, well, what about the rest of Washington, D.C.? Well, it turns out that very few fountains work. And then the Memorial Bridge. It turns out that needs about $150 million. So we’d better get on it.”

The Memorial Bridge spans the Potomac River between Washington and Arlington, Va. and about 68,000 vehicles cross it daily. A total overhaul of the bridge is set to cost about $250 million, the National Park Service said last year, warning that repairs must be completed by 2021 to avoid serious structural problems.

Zinke’s comments were some of the first by a Trump nominee on infrastructure spending, a topic that congressional Republicans have been eyeing warily amid concerns about the cost and scope of Trump’s ambitions.

Disclosing few details, Trump has pledged that his infrastructure program would cost half a trillion to a trillion dollars, paid for with a mix of federal dollars and possibly tax credits.

An exchange Tuesday between the nominee and Sen. Tammy Duckworth (D-Ill.) was among the most intense confrontations in the hearing. Duckworth asked Zinke if he deplored some of the president-elect’s statements about women, particularly that sexual harassment in the military was inevitable because they serve in close proximity to men.

Duckworth said women at the National Park Service who’ve come forward with serious claims of sexual harassment are employed by Interior. “You yourself have a history of saying women who served in combat were a distraction that weakened the force,” Duckworth said. “Do you think serving in the front line of the park service weakens the force?”

Zinke told Duckworth, “I take issues of sexual assault and harassment absolutely seriously. As you know as a military commander, the tolerance is zero.”

Duckworth, a former U.S. Army lieutenant colonel, served in the Iraq war as a helicopter pilot, a role she chose to take because it was one of the few combat roles open to women.

In the past, Zinke has cast doubt on the role of women in combat roles several times. During his first congressional campaign in 2013, Zinke criticized the Obama administration’s plan to drop the prohibition on women in combat roles, telling the Newsmax website that the military was “not ready” for the change.

“Physically, I think there are some women who can do it. But the issue is what are the unintended consequences? This is not a Demi Moore movie,” he told the website.

Zinke reminded Duckworth Tuesday that his daughter is a Navy diver.

If confirmed, Zinke would take over a park service where women wildfire fighters have been followed, touched and spied on in showers. When confronted, perpetrators were allowed to retire with benefits. Congress heard similar stories from women who serve in the Forest Service under the Agriculture Department.

Zinke’s position on climate change is a concern of conservationists at Interior because of the department’s oversight of the fossil fuels under those federal lands and their potential for increasing greenhouse gases. Experts estimate that 40 percent of the coal burned in the United States comes from land owned by the federal government. As secretary, Zinke would wield power over hundreds of millions of acres and the oil and minerals beneath them.

In 2010, while in the Montana legislature, he was one of more than a thousand lawmakers nationwide who signed a letter calling for clean-energy jobs and climate-change legislation from President Obama and Congress. Four years later, however, a former chair of the Montana Conservation Voters accused him of denying that climate change is occurring and caused by burning fossil fuels.

Zinke, 55, also reiterated Tuesday that he opposes selling land owned by the public.

“I am absolutely against transfer or sale of public land,” he told Sanders. That stance puts the first-term congressman on par with Trump, who has also said he wants to keep federal land.

Although he often votes against environmentalists on issues from coal extraction to oil and gas drilling — earning him a 3 percent voting score from the League of Conservation Voters — his position against federal land sales was serious enough for him to quit the GOP platform-writing committee last summer after the group included language that would have transferred federal land to states.

Zinke campaigned for Congress on a platform of achieving North American energy independence, and he criticized as unnecessary a recent Interior Department plan to reduce inadvertent releases of methane, a powerful greenhouse gas that scientists say is far worse than carbon emissions in contributing to global warming.

“Clean air and clean water are absolute top priorities when we talk about responsible energy development. However, the final rule issued by the Obama administration does nothing to further protect our resources,” he said in a statement. “This rule is a stark reminder that we need to invest in infrastructure projects like the Keystone pipeline, so we don’t need to flare excess gas.”

His support of Keystone pleases the oil and gas industry but is a another worry for conservationists, who fear that Trump will attempt to resurrect the billion-dollar project the Obama administration halted in September.

If confirmed, Zinke also would be the steward of the National Park Service and such vast treasures as Yellowstone, Yosemite and the Great Smoky Mountains, as well as the Fish and Wildlife Service and its huge wildlife refuges. He would have oversight of the Endangered Species Act, with a say over what animals are listed, and the National Mall, the capital’s most visited tourist destination.

The secretary guides the Bureau of Land Management’s oversight of the sagebrush sea, an area covering 11 western states, where conservationists and energy companies have fought over projects threatening the health of the greater sage grouse. And the person chosen by the secretary to lead Fish and Wildlife determines which animals get endangered-species protection — and which do not. The agency is engaged in an international fight to protect elephants and rhinoceros from poachers and to curb the sale of artifacts from those animals in the United States.

One enforcement action, Operation Crash, has resulted in numerous arrests of foreigners and U.S. citizens illegally trafficking rhino horn. The question is whether those efforts would continue under Zinke.

The former Navy SEAL, a Montana native who draws support from many sport and recreational fishermen, is expected to sail through the confirmation process generally unscathed. He was not listed as one of the eight Trump Cabinet picks that Senate Democrats intend to try defeating or at least discrediting during their hearings. The committee considering his nomination is chaired by Sen. Lisa Murkowski (R-Alaska) and includes high-profile lawmakers such as Sen. Jeff Sessions (R-Ala.) and Sen. Bernie Sanders (D-Vt.).

The selection of Zinke for the Interior post came as a surprise and a bit of a setback for Senate Republicans, given that many expected he would run in two years against incumbent Sen. Jon Tester and help the GOP snatch that seat from a moderate, if vulnerable, Democrat. Instead, Tester and Sen. Steve Daines (R-Mont.) spoke on Zinke’s behalf before the Senate panel on Tuesday.