The pupils from Duchess's Community High School took strike action to protest at what they said was a lack of Government action to combat the climate crisis.
Around 30 Alnwick YouthStrike4Climate activists gathered at 9am and marched into the town centre, waving placards and chanting, 'No change, no future'.
They paused briefly in the Market Place before continuing their morning's demonstration around the town and heading back to school.
They were joined by three students, Rowan Harris-Jones, 15, his sister Poppy, 13, and Elana Perkins, 12, who pedalled a 'carbon-neutral' go-kart 30 miles from Rowan and Poppy's home in Lowick to Alnwick in relays after school during the week. They travelled from Lowick to Chillingham on Monday evening, from Old Bewick to Edlingham on Tuesday, and from Edlingham to Alnwick on Wednesday.
One of the event organisers, Year 9's Daisy Carnegie, who spearheaded a two-pupil protest in Alnwick in March, was delighted with the turn-out, and said: "We're doing this because we don't think the Government is doing enough to stop climate change. They've said that climate is now a big issue but they are not doing anything towards it, so we want to let them know that we want business."
Another organiser, Matthew Bradley, 15, told the Gazette: "We are doing a climate strike because the Government isn't doing enough action. Declaring emergencies isn't actually solving the problem. They have to do something quickly because a study emerged last year that we only have 12 years to stop it by 50% at least otherwise it's unstoppable."
Rowan said: "If the Government doesn't listen and do something, it is going to be too late. Education is important, but I would rather have a planet to live on than education."
Yesterday's action was part of a series of events throughout the world to highlight the issue of global warming. On February 15, an estimated 10,000 students across the country went on strike and around 50,000 took part on March 15.
The YouthStrike4Climate protest, an event hosted by UK Student Climate Network (UKSCN), was inspired by Greta Thunberg, a 16-year-old climate change activist from Sweden, who has been skipping school every Friday since August 2018 to lobby the Swedish government to take action.
The UKSCN website declares: 'We are choosing to rise up and take direct action where older generations have failed. We are already facing devastating and irreversible impacts around the world. This is our final chance to fight for our futures, and our ages will not be what stop us.'
Parents and carers of Duchess's High School students were asked to inform the school by 8am yesterday if their child was planning to take part in the demonstration.
A letter from headteacher Maurice Hall made the school's position clear. It said: 'Striking involves students not being in school on Friday morning and, potentially, being in the centre of Alnwick voicing their concerns. As a school, we cannot authorise any absence of our students to be involved in such an event. Northumberland Local Authority are clear in that any absence will be considered ‘unauthorised’. Also, we cannot accept any responsibility for the safety of any of our students who take part.
'To be clear, we will not allow our students to register in school and then ask to leave the site.'