Addressing the huge crowd that turned out to the city's Civic Green at midday, 11-year-old Merrivale Primary School student Freya King said global warming was everyone's business.

"Let's face it, global warming is a big problem. It affects everywhere, not just Australia," she said.

"If we don't do something about it in the next couple of years, the children of today will not have the future that we imagine or dream of.

"So what are the governments and other countries doing about global warming?"

She said that since Australia signed up to the Paris Agreement, its emissions continued to rise.

"In the last 10 years Australian's emissions have risen by 16 per cent, Australia has one of the largest carbon emissions per person in the world," she said.

"We have to act now."

Protesters of all walks of life stood alongside students to call for action on climate change.

Family Le Lou Berger, Ariel Berger and Becky Nevin Berger attended the strike together.

"We're sick of the politicians not realising what's happening to our planet, and they're just going to leave the mess with us," Le Lou said.

"We want them to stop drilling oil, hurting our Great Barrier Reef and burning fossil fuels."

Maisey and Claudia,13, said everyone could do their bit to reduce the impact of climate change.

"We've come down because our future matters and the politicians of Australia and the world aren't really doing enough," Maisey said.

"So we have to take it into our own hands."

"It's the small things that really count, definitely cutting down on plastic, walking wherever you can and taking public transport where you can't walk," Claudia said.

Radio presenter and independent candidate for Wannon in the 2019 federal election Alex Dyson hosted the event, and said it shouldn't be up to kids to come up with solutions for politicians.

"It doesn't matter what side of politics you're on, we want you to be able to identify and admit there's a problem, and that it is indeed an emergency, and take drastic steps to reduce climate change," he said.

"I don't mind what the steps are, but they need to be large and they need to be urgent.

"I want them to talk to the CSIRO and hear what they have to say as you would with any other expert.

"Hit it hard, hit it fast and stop delaying things."

The Red Tent Singers led a chorus and chant which was heard across the CBD as strikers showed off their colourful handmade signs.

Dr Alecia Bellgrove is a senior lecturer in Marine Biology and Ecology at Deakin University, and heads the DeakinSeaweed Research Group in the School of Life and Environmental Sciences and Centre For Integrative Ecology.

She said climate change was having a tangible impact on local marine life.

"We're seeing range extensions of warm water species down into cool waters, we're seeing mass extinctions of species across the marine environment as well as the terrestrial environment and we're seeing losses of important habitat," she said.

"With massive flow-on effects to recreational fisheries, commercial fisheries and the functioning of our ecological systems.

"We can all live gently on the earth, but we need political leadership and we need action now."

South-West Coast MP Roma Britnell said energies would be better spent on volunteering and planting trees.

"While I support everyone's right to a peaceful protest, in this instance I feel energies would be better used on actions that will be more effective - perhaps committing to regular volunteering with a landcare or coastcare Group, planting trees or committing to take a bag to the beach and picking up plastic," she said.

"It could be something as simple as writing letters to the largest manufactures and retailers to object to excess plastic packaging. Consumers are powerful.

"Or even starting a waste free school lunch movement, with a focus on a reduction of plastic. These things will help reduce waste going to landfill.

"I never have and never will deny climate change exists or that humans are having a far greater impact on the environment than ever before. However I would never instill fear that there is nothing we can do. We can all make a difference."

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