YOUNG activists are asking adults across the city to join them when they walk out of school and university over climate change.
Schoolchildren and union bosses in Portsmouth are set to demonstrate for 30 minutes on September 20.
The University and College Union will soon meet the Trade Union Congress to call for the workday stoppage.
Activists met at Fratton Community Centre on July 25 to organise the city’s role in the drive, set to occur three days before a UN climate summit.
Twelve-year-old Portsmouth schoolboy, Judah Hurr, will be among those staging a walkout.
He said: ‘We have to fight for our future or we will not have one.
‘We need adults to work with us, we can’t do it on our own.’
Judah was one of dozens of schoolchildren to walk out of lessons in Portsmouth and protest over climate and carbon emissions earlier this year.
He will join others like Sarcha Wheeler, a University of Portsmouth student, for the protest in two months’ time.
‘Some children have spent their entire lives breathing in toxic air,' she said.
‘We all need to take action together to get carbon emissions and pollution cut from our city.’
Jon Woods, chairman of Portsmouth City Unison and Portsmouth TUC, said youngsters like Judah and Sarcha were ‘absolute heroes’ for standing up for climate change – but insisted they can not solve the problem alone.
‘It's a brave step for them to take to walk out of school, especially not knowing whether they’re going to face sanctions,' he said.
‘But they should not be doing this alone, we have a responsibility to fight for their planet – we have to show solidarity.'
Portsmouth joined the protest after a call was sent out by young climate change strikers from across the globe, including Greta Thunberg.
The city's role in the demonstration is yet to be decided, but will take place in Guildhall Square on the day.
‘The National Education Union supports student action against climate change and their stand against government complacency,’ said Sarah Bolton, NEU Hampshire South East district secretary.