Council leader Nancy Platts and opposition leader Phélim Mac Cafferty said that they would join children missing school for a “climate strike” next week.
They also agreed that Brighton and Hove City Council should work with schools to support young people who want to take part in the protest.
They gave their backing at an urgent meeting of senior councillors at Hove Town Hall to discuss the proposed climate strike on Friday 20 September.
It is the latest in a series of monthly climate change protests which started in February.
Two of the young people who plan to take part – Uma Krieger and Annapurnea Marley – listened to the town hall debate and were delighted with the outcome.
Miss Krieger said: “It is really great to get it passed. I hope everyone who was not allowed to strike will now be able to.
“It is really good to have the support of adults and the majority of the council.”
Miss Marley told councillors that students were not protesting at the weekend because they did not believe that people would take any notice of them if they did.
Councillor Platts, the Labour leader, praised the young women for coming along to speak on behalf of the campaign and enabling the action to happen.
She said: “As someone who was involved in environmental issues more than 30 years ago, I wish we had done what you have years ago as maybe we wouldn’t be in the mess we are in now.
“You have been inspirational with your leadership on this issue and I look forward to joining you along with other members of the Labour Party at the climate strikes.”
Pinaki Ghoshal, the council’s executive director for families, children and learning, said that it would be up to schools to decide whether students could take time off lessons.
But, he said, the council would send advice to head teachers, suggesting that they require written permission from parents for their children to be out of school.
Secondary school pupils should have a member of staff accompanying them to the march.
Primary school pupils would be expected to collect them for the event.
Mr Ghoshal said: “It is not for the council to tell schools what they should do. We have provided some guidance and each school can make its own decision.”
cheap theatre :: the end on the world will not be in brighton == Humanity is trying to avoid imminent doom but it is not true
This too is about education as well as making kids conscious of their own roles in citizenship issues. Perhaps it will inspire more of them to take up walking to school too – Mary is right about that!