Former E.P.A. chief Gina McCarthy accepted her nomination as the first-ever national climate advisor to head the new White House Office of Domestic Climate Policy.

"I'm here today because climate change is not only a threat to the planet. It is a threat to our health and our well-being," McCarthy said. "It's a threat to people everywhere and the precious natural resources that we depend on."

Defeating this threat, she went on, "will require engagement of every community, every sector in our nation and every country in the world."

In the role, she said she will work directly with communities and harness "the force of science and the values of environmental justice."

Biden referred to McCarthy, who currently serves as president and CEO of the Natural Resources Defense Council, as a "policy wonk and a people person, problem solver and coalition builder."

While E.P.A. head under the Obama-Biden administration, she led the effort of lowering carbon emissions from power plants and conserving critical water sources, he said.

McCarthy will work closely with former Secretary of State John Kerry in the new role, Biden said.

Southern Environmental Law Center Regulatory Policy Director Brenda Mallory told Biden and Vice President-elect Kamala Harris she was "honored and humbled" by her appointment to be chair of the Council on Environmental Quality.

Mallory highlighted her upbringing in Waterbury, Connecticut, for shaping her commitment to fighting the injustices brought on by climate change.

"I know the faces of the marginalized, and I appreciate the challenges of urban pollution. While the words 'climate change' and 'environmental injustice' were not part of the vernacular back then, the evidence of their impact was all around," she said.

Mallory promised to revitalize the Council on Environmental Quality, saying "CEQ will work with a broad range of partners on a broad range of issues, tackle the full breadth of climate change, preserve the natural treasures of our nation, center environmental justice and help more communities overcome legacy environmental impacts.

In accepting his nomination as E.P.A. administrator, Michael Regan drew attention to the "connection between our environment and our health."

Growing up in eastern North Carolina, he said he "developed a deep love and respect for the outdoors and our natural resources," but that he "also experienced respiratory issues that required me to use an inhaler on days where pollutants and allergens were especially bad."

"We will be driven by our convictions that every person in our great country has the right to clean air, clean water and a healthier life, no matter how much money they have in their pockets, the color of their skin or the community that they live in," he said. "We will move with a sense of urgency on climate change, protecting our drinking water, and enact an environmental justice framework that empowers people in all communities."

The nomination is a "dream come true," said Regan, who previously served nearly a decade at the E.P.A. under both Democratic and Republican presidents.

A graduate of North Carolina Agricultural and Technical State University, he said he also was honored to join Vice President-elect Kamala Harris as a "fellow HBCU graduate in this administration."

On the nomination, Biden noted that Regan, currently secretary of the North Carolina Department of Environmental Quality, would be the first African American man to run the E.P.A.

Former Michigan Gov. Jennifer Granholm accepted Biden's nomination as energy secretary Saturday.

"My commitment to clean energy was forged in the fire," Granholm said. "Joe Biden and the Obama administration worked with us to rescue the auto industry and the million jobs that are attached to it. They worked with us to retool and electrify Detroit for the future, of course, and to diversify Michigan's economy on the premise of this promising future in clean energy."

The former governor stressed the importance of investment in clean energy to produce new jobs.

"Over the next two decades, countries and companies are going to invest trillions... in electric cars and batteries and wind turbines and solar panels and energy-efficient appliances and energy-efficient buildings," Granholm said.

"Millions of good-paying jobs are going to be created, millions. But where? Where will those jobs be?" She asked. She said "The path to building back better [is] starting with building and manufacturing and deploying those products here, stamping them “Made in America,” and exporting them around the world."

Biden's nominee for energy secretary highlighted her family's history, as immigrants from Canada, and the importance of good-paying jobs.

"It's because of my family's journey and my experience in fighting for hardworking Michigan families that I have become obsessed with creating good-paying jobs in America in a global economy, obsessed with seizing the opportunities that a clean energy future will provide for American workers. So we can stand on the sidelines and let other countries beat us to these opportunities, or we can get in the game," Granholm said.