WASHINGTON (NEXSTAR) — Gathering near the U.S. Capitol Thursday morning, more than 500 moms and kids rallied to urge Congress to take action to stop climate change.

It was the sixth annual Play-in for Climate Action, where moms and youth climate strikers from 25 states said things need to change before it’s too late.

“We want 100% clean energy by 2050 or else we’re doomed,” demonstrator Karin Stein said.

She said the effects of climate change are already at play in her home state of Iowa, where there was devastating flooding this spring.

“My heart breaks. I see local economies disrupted,” she said.

Alexandria Villasenor, 14, of California, is leading the charge. She said members of her generation are the ones who will pay the price if nothing changes.

“We do have a Congress full of climate (change) deniers, and so we really have to push for change,” she said.

Organizers said the event isn’t about scaring kids, but rather about teaching them about the importance of taking care of the planet.

“When I was their age, that was not on my mind and so it gives me hope for the future,” Rep. Donald McEachin, D-Va., said of the youth protesters.

He was among several Democrats who stopped by the rally.

“I believe that the environment is the single most important issue of the 21st century,” McEachin said.

He said that unlike the Republican-controlled Senate, the Democrat-controlled House is ready to act. But House action is unlikely to make it past President Donald Trump.

On Monday, the Republican president said Democrat proposals like the Green New Deal are job killers.

“These radical plans would not make the world cleaner,” Trump said during a press conference. “Their plan is estimated to cost our economy nearly $100 trillion.”

Activists disagree and they say they’ll be back in Washington for a play-in every summer until their goal is met.

“We can do it and we absolutely must,” Stein said.