Updated at 1:30 with additional Texas nominees sent back to President Donald Trump.

WASHINGTON — Democrats successfully stalled the nomination of Kathleen Hartnett White, a climate change skeptic President Donald Trump nominated to be a top White House environmental adviser.

If Trump still wants the former Texas regulator to lead his Council on Environmental Quality, he'll have to nominate her again.

Sen. Tom Carper, the senior Democrat on the committee that oversees the EPA and environmental policy, vowed Tuesday to block White from rolling over into 2018 automatically with other pending nominations. He delivered on that late Thursday, when the Senate excluded her from a list of nominations to resume debating in the new year.

The process will have to start over for White, the former chairwoman of the Texas Commission on Environmental Quality. The Committee on Environment and Public Works approved her last month, but the post requires confirmation by the full Senate.

The council coordinates federal environmental efforts and ensures that agencies meet their obligations under the National Environmental Act.

Democrats oppose White, who has been openly skeptical of scientists' consensus regarding the impact of human activity on climate.

I will object to any agreement that allows Ms. White's nomination to be held over into the second session of the 115th Congress. Let's start the new year off with a clean slate and allow @POTUS the opportunity to nominate a qualified leader for CEQ. https://t.co/mob11Sgnqd — Senator Tom Carper (@SenatorCarper) December 19, 2017

"I am hopeful that President Trump will seize on the opportunity to start the new year and the new session of Congress off on the right foot by nominating a new and better qualified candidate to lead this consequential office," Carper said.

White faced a tough confirmation hearing before winning committee approval along party lines. Democrats grilled White about remarks she made as a fellow at the Texas Public Policy Foundation, a conservative think tank in Austin.

Nearly 50 environmental advocacy groups urged lawmakers to reject White. Last month, more than 300 scientists called on senators to oppose her nomination.

White isn't the only Texas nomination that will be sent back to the White House. Trump will also have to re-nominate former Texas Comptroller Susan Combs, who was picked to be assistant secretary of the Interior Department, and Northern District Court nominee Matthew Kacsmaryk.

The Senate Energy and Natural Resources Committee delayed Combs' vote when a July meeting to approve her was abruptly canceled, likely because of politics surrounding the GOP's effort to repeal the health care law. The committee approved Combs a week later, but she's been waiting for a Senate vote ever since.

And Trump's pick of Kacsmaryk, general counsel for the Plano-based First Liberty, for the Northern District, proved controversial.

A coalition of 200 human and civil rights groups opposed Kacsmaryk, asserting in a letter to the Senate Judiciary Committee that he "fundamentally disapproves of LGBT people." They referred to a 2015 op-ed that Kacsmaryk wrote titled "The Abolition of Man ... and Woman," in which he said those legislating and litigating same-sex marriage are attempting to remove a "pillar of marriage law."

Kacsmaryk wrote that Facebook’s menu of gender identity options — 51 at the time — make “it seem as though the human person is more like a pluripotent cell whose sex and sexuality are subject to autonomous self-definition.”

The Judiciary Committee held a hearing on Kacsmaryk's confirmation Dec. 13 but did not approve him.