DENVER — She's hard to miss as she wanders through Denver International Airport (DIA), her bag in one hand, her trusty sign with the words, "School Strike For Climate" in the other. 

"I’m trying to bring my sign, but I don’t know if it’s going to get through security," said Haven Coleman, a 13-year-old Denver Public Schools student. 

But unlike many teens her age, school is not her biggest worry. 

“I’m just a person trying to do stuff that actually a human should be doing," she said. "Not destroying, just helping." 

She's a climate change activist, who has been going on strike every Friday since Jan. 4. 

That's 37 Fridays. 

Thirty-seven days of cutting class. 

“Because it’s my future," she said. "Because it’s my generations future. Because why wouldn’t you care about things? Like if it’s going to be hurting you or hurting the world, then you’re trash." 

Coleman strike
Nicole Coleman

Usually she's a one person protest, but that changes on Friday, Sept. 20 as students from around the world play hooky to join the Global Climate Strike. 

Coleman was invited to march with Greta Thunberg in New York City. 

Thunberg, a 16-year-old youth activist from Sweden, testified in front of congress and was nominated for the Nobel Peace Prize. 

RELATED: Teen activist to lawmakers: Try harder on climate change

"We're actually doing the stuff that you guys are supposed to be doing," said Coleman. "We're trying to get your guys' attention. I'm talking to adults." 

Inspired by Thunberg, Coleman co-founded the U.S. Youth Climate Strike with two other teen activists.

Coleman said striking can start a movement and get people to pay attention to the climate crisis. 

But she said the lifestyle changes count too, like biking to school or work and being a vegetarian or a vegan. 

"Do literally anything you can," she said. "Everything counts. But if you're willing to do the bigger stuff, do the bigger stuff. And be safe during the strikes." 

Coleman strikes with the support of her family, and she'll be in NYC striking and at the UN Youth Climate Summit all week. 

DPS said if students plan to strike, they need permission from their parents or their school for the absence to be excused. 

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