The eight-year-old – accompanied by his dad and a giant placard –was one of 5000 people protesting in Sydney’s Martin Place on Friday against the federal government's climate change policies.

The "Strike 4 Climate Action" event was inspired by a 15-year-old Swedish schoolgirl's activism and involved children in Australian capital cities and 20 regional centres.

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Though earlier this week Prime Minister Scott Morrison said the nation needed "more learning in schools and less activism".

Mr Park didn’t agree.

“You try to guide your children in lots of things, even if it’s something as simple as keeping them healthy and brushing their teeth … this just follows along from that line that there are ethical issues about what we feel is right,” Mr Park said.

“By the time [Leo] has children it’s going to be a very expensive mess – I think financially and ethically we’re much better to do something now and taking action.”

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It comes as Resources Minister Matt Canavan told radio 2GB on Friday, students should be learning to drill for oil while protesting would only teach them to “join the dole queue”.

“Activism is what politics is about … you’d think they would be pro people standing up for democracy and having a say,” Mr Park said.

“Climate change is a really major issue that isn’t taken seriously – it’s almost like a click and move on sort of topic for a lot of people.”

Leo was one of three from his grade two class to ditch classes for the day, with staff quite “relaxed” about them leaving.

“He’s learning about being able to stand up for his rights,” his father said.