President-elect Joe Biden on Saturday introduced members of his climate and energy teams in Wilmington, Del., nominees and appointees he said would lead his administration’s plans to address climate change, “the existential threat of our time.”

“We literally have no time to lose,” said Biden. He noted that, this year alone, wildfires had burned more than 5 million acres across the West, hurricanes and tropical storms had pummeled the East and Gulf coasts, and droughts had ravaged parts of the Midwest.

“So many climate and health calamities are colliding at once. It’s not just the pandemic that keeps people inside. It’s poor air quality,” Biden said of one of the many effects of climate change. “Folks, we’re in a crisis. Just like we need a unified national response to covid-19, we need a unified national response to climate change.”

His climate and energy teams would be ready on day one, he said, with a focus on creating new jobs in “climate-resilient infrastructure” and clean energy.

On Thursday, Biden chose Rep. Deb Haaland (D-N.M.) to serve as Interior Department secretary. If confirmed, Haaland would be the first Native American Cabinet secretary in the nation’s history.

Also this week, Biden chose North Carolina environmental regulator Michael S. Regan to become the first Black man to head the Environmental Protection Agency, as well as Obama administration veteran Brenda Mallory to serve as the first Black chair of the White House Council on Environmental Quality.

Biden also selected former Michigan governor Jennifer Granholm for secretary of energy, former EPA administrator Gina McCarthy as national climate adviser and Ali Zaidi, New York’s deputy secretary for energy and environment, as deputy national climate adviser.

All six shared the stage with Biden and Vice President-elect Kamala D. Harris on Saturday at the Queen Theater in Wilmington. As in past events, where Biden introduced his Cabinet picks, the would-be nominees and appointees spoke as much about their personal histories as their qualifications and plans for the job.

Haaland spoke about how growing up in her mother’s Pueblo household made her “fierce” and acknowledged that she stood on the shoulders of her ancestors. She noted the history of Native American kids being taken away from their families and sent to boarding schools, an effort to destroy their traditions and identities, she said.

“This moment is profound when we consider the fact that a former secretary of the interior once proclaimed his goal was to ‘civilize or exterminate us.’ I’m a living testament to the failure of that horrific ideology,” she said.

Granholm praised the Obama-Biden administration for helping revive the auto industry during the last recession and lauded her Canadian parents, who came to the United States for work when she was 4.

President-elect Joe Biden introduced North Carolina environmental regulator Michael S. Regan as his pick to head the Environmental Protection Agency on Dec. 19. (The Washington Post)

Regan, who noted he was a fellow HBCU graduate like Harris, reminisced about growing up hunting and fishing in eastern North Carolina while also having to use an inhaler.

“I’ve always been curious about the connections between our environment and our health — how the world around us contributes to, or detracts from, our enjoyment of life,” said Regan, who added that environmental challenges could not be solved by regulation alone.

Growing up in the working-class town of Waterbury, Conn., meant Mallory knew “the faces of the marginalized” and appreciated “the challenges of urban pollution.” McCarthy recalled that childhood “beach days” meant swimming in Boston Harbor, where she would emerge from the water with oil and other things stuck to her skin. Zaidi said he saw promise in the jobs that could be created in tackling climate change.

“When my parents moved from Pakistan to Pennsylvania, they brought two little kids and a few suitcases of dreams — dreams their kids are living today,” Zaidi said. “To be healthy, to have purpose, to be able to give back: That is how our parents taught us to define the American Dream.”

Closing out the event, Harris recalled visiting California earlier this year as wildfires raged across the West and seeing “heartbreaking” scenes: charred playgrounds, neighborhoods in ashes and some of the most toxic air anywhere in the world.

“Our climate crisis is not a partisan issue, and it is not a hoax,” Harris said. “It is an existential threat to all of us, particularly poor communities and communities of color who bear the greatest risks from polluted air, polluted water and a failing infrastructure.”

Juliet Eilperin contributed to this report.