A crowd of more than 100 Kangaroo Island residents, young and old, joined of the global Climate Strike action protest on Friday at 12noon.
The group gathered on Kingscote Esplanade before marching through the streets of the central business district of Kingscote.
The group, led by a large contingent of KICE students, did two laps before ending up in front of the KI Council building.
Among the students were several of the Year 12 class, who like the others walked down from the school of their own accord.
Among them were Georgie Sullivan and Bridget Black, who said the students were not taking the whole day off school, but just enough time to attend the action.
They defended their right to join the protest and said they had not been brainwashed and believed the science of man-made climate change.
"We wanted to be here today to show to the public that people care about this issue, especially young people because it's our future," they said.
"The voices of young people deserve to be heard and it's easier to be heard in a group.
"We are too educated to be brainwashed and taking off an hour and half for one day is not going to affect our education."
There were also members of Kangaroo Island Uniting Church congregation present, one holding a sign stating "For the whole creation, Act now".
Kangaroo Island Victor Harbor Dolphin Watch coordinator and former teacher Tony Bartram estimated the crowd to about 150 people.
KI mayor Michael Pengilly expressed his personal disappointment that students were protesting in school hours.
"(The protest) won't gel with the vast majority of Islanders and is a total green left con job," Mr Pengilly said. "I am disgusted with kids being used in such a manner."
A said the real story for the day was the fantastic rain Kangaroo Island was receiving, which could translate into millions of dollars for the local KI economy.
Federal Finance Minister Mathias Cormann meanwhile warned public servants to stick to the rules if planning to walk off the job for Friday's climate strikes.
Senator Cormann also told students to go to school instead of joining the rallies around the nation.