"Climate change is not a lie, we won't let our planet die," was one of their many chants as they marched down Market Street in San Francisco.
The truth is these students didn't actually ditch school on their own. Their schools were behind their participation in the march against climate change.
"Us youth, we are, I feel like we really need to change it and make a stance for who we are and how we feel," said Marcos Becerra, a student at Urban Promise Academy in Oakland.
Their intentions were clear, to target lawmakers who have the power to change policy and laws.
Students protested in front of the offices of Senator Dianne Feinstein and House Speaker Nancy Pelosi.
Young supporters have, in fact, been active in the "Climate Strike" movement.
Most recently Senator Feinstein was criticized for arguing with children who came to her office. It was captured on cell phone video.
Student 1: "We're the people who voted for you. You're supposed to listen to us, that's your job."
Sen. Feinstein: "How old are you?"
Student 1: "16."
Sen. Feinstein: "You didn't vote for me."
Student 2: "It doesn't matter we're the one impacted."
"We need to show them what we want, the young people who are soon to be voters and they are going to listen to us if they want to remain in power because this is change happening now," expressed Maggie Maloney, a student.
This was not an only-in-San Francisco moment. Students from 123 countries and more than 2,000 cities from all over the world participated in these marches.
Their message Friday was if you don't act like adults, we will.
For more information about Youth Climate Strike go here.