SEATTLE — As Grace Lambert stepped up to the podium, an excavator hummed and beeped just feet away as it lifted dirt from the ground.

Hundreds of teens sat on the turf of the baseball field at Cal Anderson Park, sun shining on their backs. They faced the stage tucked into the diamond’s backstop.

They held colorful, handmade signs with messages including “There is no planet B,” and “The oceans are rising and so are we.”

“We here in Seattle are striking with youth around the world to demand our leaders take action to ensure a livable planet for all,” Grace told the crowd. “We are striking for the Green New Deal, and to move to 100 percent renewable energy.”

Grace, 16, is a junior at Henry M. Jackson High School in Mill Creek. She planned the meetup on Friday morning, where students skipped school to protest climate change.

The strike wasn’t just happening in Seattle, or even throughout Washington state. It’s been reported that 1 million students around the globe missed class to participate in the Youth Climate Strike. The protests were started in August by Swedish activist Greta Thunberg, 16.

The movement’s leaders have a list of demands. It includes cutting greenhouse gases in half by 2030, to stop all fossil fuel projects and to declare climate change a national emergency.

Grace hopes the strikes show local, national and world leaders how serious climate change is to the students.

“We all know how important school is,” she said. “But if we just go to school and study, that doesn’t mean we’ll have a future.”

Grace saw posts about the strikes on Twitter at the beginning of February. She wanted to get involved, but there wasn’t any group in Washington. She reached out to the national team, she told The Daily Herald on Tuesday.

“I was like, ‘Can we make something happen?’” she said. “The national team was like, ‘Yes you’re the state lead now.’”

She sent a text to a group of her friends. Her cousin Ashley Lambert messaged back: “Sign me up for anything to save our planet.”

They live just a few blocks away from each other near Mill Creek. They became the main organizers, along with their friend Chelsea Li.

Ashley, 17, is a senior and also attends Jackson.

“As climate change gets worse, it’s going to get worse for minorities and people of color,” she said. “When it goes really, really bad, the people with power, rich white people typically, will see less effects.”

She and her cousin had no experience putting together an event this big. They’ve had to learn how to write press releases, how to apply for city permits and more.

At the same time, the girls have been balancing schoolwork and sports. They’ve spent the past few weeks answering emails during their lunch period.

“Sometimes you just have to close the computer and do statistics for an hour,” Ashley said.

Their parents have been a big help.

Both families believe climate change is a challenge and that activism can make a difference, said Grace’s father, Ryan Lambert.

“They are smart young women who saw a problem and wanted to do something to address it,” he said. “There was never a question of supporting this or not.”

The national movement invites students to strike every week until they start to see changes.

Grace and Ashley realize that’s not possible for everybody. Instead of striking weekly, the pair might plan more large events.

Grace went to sleep at 1 a.m. on Thursday. She and Ashley were at the park about six hours later.

Around 40 volunteers showed up to help, and they were finished setting up in about an hour. Fellow protesters started to arrive around 10 a.m.

Toddlers held signs high above their heads and jumped around during chants. One speaker asked people to hold up their arms when their age was called. The majority were 15 to 20. They spent the morning surrounded by the fossil fuels they oppose — cars and buses circled the block, while construction was going on down the street. Airplanes flew overhead.

The Friday rally was streamed on Facebook so those who weren’t able to make it could watch.

There were nearly a dozen speakers — both teenagers and adults. Most talked about groups who could be most affected by severe climate change. Ashley was the last to speak.

Stephanie Davey: 425-339-3192; sdavey@heraldnet.com; Twitter: @stephrdavey.