Children are skipping the climate strike because of intimidation from schools, the Auckland organisers says.
Kids will protest across the country on Friday over what they have called 30 years of inaction on climate change.
But Gwyneth Parallag and Sarah Paton-Beverley told The AM Show some people will miss out on the strike because of their school's stance.
"That's mostly because of intimidation by schools I think," Sarah said.
"Every school is different and specific, but definitely some of them [are intimidating students]," Gwyneth added.
Sarah said many students don't have the right to vote, so this is their chance for them to make themselves heard.
"There will be a minority, and that is a small minority, of kids that will be wagging and just taking the day off like you [Duncan Garner] say, but the majority of people are going to educate themselves.
"They're going because this is a chance for students to be heard, we don't have the power to vote, most of us are under 18."
The first child to protest was Swedish teenager Greta Thunberg, who chained herself to her country's parliament in protest.
The movement has spread across the world, including Australia and the UK. It was announced on Friday (NZ time) Greta had been nominated for the Nobel Peace Prize.
Academics are backing the strikes and 1500 of them have signed an open letter supporting the students.
Lincoln University lecturer Sylvia Nissen told Newshub it's a signal to political leaders.
"This is a generation that can't vote, so this is really an expression of them putting their voice forward, I think it's very important that we stop and listen to what they have to say."
Dr Nissen said Government inaction on climate change is violating students' right to a future, and she hopes people take notice of what they have to say.
"Hopefully it's a message that should get across to us, that it should unsettle us into action."
What's happening where:
Wellington - Protesters will gather at 10am at Civic Square, followed by a march down Lambton Quay to Parliament. Speakers are expected.
Auckland - Midday at Aotea Square. No march is planned, but musicians, speakers and spoken word poetry is expected.
Christchurch - Kicking off at 1pm at Cathedral Square - music, guest speakers and cultural showcases from local schools.
Dunedin - Expected to start at midday with a march down George Street, then a rally in the Octagon.
Events are also planned for Nelson, Raglan, Hamilton, Whanganui, New Plymouth, Palmerston North, Russell, Lower Hutt and Kapiti.