Kangaroo Island brother and sister Mia, 13, and Tim, 10, joined thousands of other students around Australia calling for greater action on climate change.
"We want to raise awareness so that the community does more for the environment so that we kids have a future," Mia said.
The nationwide student strike on Friday, March 15 saw hundreds of students participate in Adelaide.
Both the Adelaide students and the KI pair also called on Norwegian company Equinor to abandon plans to drill a test well in the Great Australian Bight.
Mia, 13, and Tim, 10, and their mother Silke Krause attended the recent Equinor information session at the Ozone Hotel, Kingscote to find out more about that proposal.
The protest action continues on Kangaroo Island with the "Bight Back" gathering planned for the beach at Vivonne Bay at 12noon on Saturday, March 16.
Friday's student strike on KI saw Mia and Tim joined by a group of supporters on the Kingscote foreshore.
Their signs read "Stop! We are fighting for our future" and also "Strike for Climate" and "Save our Bight".
There was a range of reactions, some supportive others not, from people driving and walking past, with some saying they should not be protesting during school hours.
Mother Silke disagreed and said she supported their wish to strike.
"It is an educational experience," she said. "Mia and Tim have learned so much doing research about the issue."
The brother and sister have been inspired by Greta Ernman Thunberg, a young Swedish political activist working to stop global warming and climate change.
In August 2018, she became a prominent figure for starting the first school strike for climate outside the Swedish Parliament building.