Children walked out of school on Friday and protested outside Chesterfield Town Hall to demand urgent action on climate change.
Students around the world have gone on strike to urge politicians and businesses to help slow global warming.
They were inspired to take action by student Greta Thunberg, who has become a global figurehead since protesting outside Sweden's Parliament last year.
The youngsters in Chesterfield were allowed into the council chamber after Liberal Democrat councillor Ed Fordham saw them on the steps of the town hall.
They held placards with messages such as 'don't be a fossil fool' and 'there is no planet B'.
Coun Fordham, who represents the Brockwell ward and speaks on climate change, said: "These children are very brave and should be applauded.
"The cause they are striking for is deeply serious and action is needed now.
"Seeing the pupils outside I felt it was important that they were heard and taken seriously and I was proud to invite them all into the council chamber of the town hall.
"Carrying their banners and protest into the council chamber they spoke and questioned me and I was delighted that we were joined by chief executive Huw Bowen and leader of the council Tricia Gilby.
"In July the borough is due to debate climate change and I was able to urge the children to come back on that day and be in the public gallery and see and hear the commitments we will make.
"We have to act and we have to act now."
Councillor Tricia Gilby, Chesterfield Borough Council's leader, said: "A group of committed young people from schools across Chesterfield town and borough turned up unannounced at Chesterfield Town Hall this morning.
"We would never condone young people missing school, however, climate change is one of the key challenges facing the planet and a real concern for local young people, which is why it felt right to talk to them and answer some of their questions.
"The council is already active in taking measures to reduce its carbon footprint but we know that we need to go much further.
"On July 17, Coun Amanda Serjeant, the council's deputy leader will move a notice of motion, which will declare that our town and borough faces a climate emergency.
"This will lead to our establishing a Chesterfield Climate Change working group to respond to this challenge, which will include setting a realistic date for Chesterfield to be carbon neutral and preparing a detailed action plan to achieve this outcome.
"We would expect this work to conclude by March 2020 and would hope that many of the young people that attended the town hall will find ways through their schools and other representative associations to make their voice heard as part of this timely and important activity.
"They are, of course, the future of our great town and borough."