Tasmania's veteran conservationist Bob Brown has spearheaded an anti-Adani convoy, travelling north to protest the divisive proposed coal mine in Queensland.
The convoy of more than 70 cars, many electric, has left Hobart on its two-week campaign journey up Australia's east coast.
That number is expected to swell to more than 700 and will include prominent musicians Paul Kelly and John Williamson.
More than a hundred people rallied outside Hobart's parliament house on Wednesday morning, where Mr Brown described climate change as the biggest issue facing the country.
"We need to say to the leaders of this country 'how about you listen to the next generation instead of listening to a coal industry ... wanting to pocket more money at our expense?'," the former Greens leader said.
Further protests will be held in Melbourne, Sydney and Brisbane as the convoy heads north to Queensland's Galilee Basin.
The fleet is expected to reach Claremont on April 28. The proposed mine site is about 160 kilometres northwest of the town.
"We're going with a smile on our face. Sure this is a protest but moreover it's a celebration of this beautiful little planet," Mr Brown said.
Aside from campaigning to save the Great Barrier Reef from destruction, Mr Brown has said the convoy would help boost businesses in small towns along the way.
Ex-Greens Christine Milne leader said Australia needs to transition to renewable energy.
"We have a Morrison government deliberately burning the Great Barrier Reef in the name of jobs, growth," she told the Hobart rally.
"The age of coal, oil and gas is over."