A day after the Sunrise Movement displayed a prominent banner at the launch of Sen. Kamala Harris's (D-Calif.) presidential campaign, urging the senator to back a Green New Deal to shift the U.S. to a 100 percent renewable energy system, Harris announced at a town hall event that she supported the ambitious proposal.

At the CNN-hosted town hall in Iowa, Harris told the audience, "I support a Green New Deal" to help combat the climate crisis, which she called "an existential threat to our country."

"All children need to be able to breathe clean air and drink clean water, and we've got to have a commitment to a policy that will allow that to happen for ourselves and our children and our grandchildren," Harris said. "And right now we don't."

Sunrise Movement founder Varshini Prakash applauded Harris for becoming the fourth Democrat in the 2020 campaign to announce support for the Green New Deal. But as the group did when Sen. Elizabeth Warren (D-Mass.) backed the plan, the Sunrise Movement said it will hold Harris's feet to the fire on the policy details, including the level of urgency, embodied in the kind of Green New Deal its members are demanding.

"The Green New Deal would be an unprecedented federal government-led mobilization—on the scale of World War II and the original New Deal—that aims to achieve net-zero greenhouse gas emissions in the United States by 2030," Prakash said in a statement. "We'll continue to push the senator to make sure that the Green New Deal, for her, is more than just a buzzword."

For millennial voters and younger generations, Prakash added, "a Green New Deal is the difference between life and death"—not simply a campaign slogan.

Statement from @VarshPrakash, founder and executive director of Sunrise Movement, in response to @KamalaHarris’ endorsement of a #GreenNewDeal tonight pic.twitter.com/KieAAyYhSf SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— Sunrise Movement (@sunrisemvmt) January 29, 2019

Since the midterm election, the Sunrise Movement has successfully convinced 45 members of the House to support the Green New Deal, which is expected to create 10 million jobs in its first decade as Americans get to work creating 100 percent green infrastructure and technology. Among 2020 candidates, Warren and Harris are joined by Sen. Kirsten Gillibrand (D-N.Y.) and former Obama administration housing Secretary Julian Castro in expressing support for the plan.

At Harris's campaign rally in Oakland on Sunday, the group sent a clear message to the senator and other Democrats hoping to challenge President Donald Trump in 2020.

"Listen up all you presidential hopefuls—if you're not fully supporting the Green New Deal, you're falling behind," the organization tweeted.