Activists involved in the protest that saved the Franklin River say the environmental win would not have been possible under today's tightened protest laws.
During the Franklin River blockade in 1982, protesters attempted to slow construction work of a dam for a hydro electric scheme in Tasmania's remote south-west that would have flooded the river and surrounding landscape.
More than 1,250 protesters were arrested for trespassing into the area where the dam was being built.
The protest defined the environmental movement in Australia and helped contribute to the eventual protection of the Franklin River as a World Heritage site that is still enjoyed today.
One of those who risked jail as part of the blockade was Christine Milne, then a school teacher in Devonport, Tasmania.
For protesters like her, jail time was part of the objective: by refusing the bail conditions of not returning to the protest site, they showed defiance and clogged up Tasmania's prison system.
But she says the penalties they faced were not as severe as today.
"When I was arrested and went to jail, it was for a misdemeanour. I did not end up with a criminal record," she says.
Milne and others have raised their fear after a string of new laws targeting climate protests in recent years.
In New South Wales, laws have been introduced which penalise protesters who block major roads with jail time for two years and a fine of $22,000.
And similar laws targeting climate activism have been passed around the country.
Milne says it represents a threat to protest in Australia.
"A young person who would like to be involved in direct action now risks a hell of a lot more than those of us 40 years ago," she says.
The criminalisation of protest
Last year, climate protester Violet Coco was sentenced to 15 months' jail for blocking one lane of traffic on Sydney Harbour Bridge for 28 minutes during a climate protest.
It was the 27th time she'd been arrested during peaceful protest action, and the first time she'd been sentenced to jail time under the new NSW laws.
The sentence was condemned by multiple organisations. Human Rights Watch called the sentencing "incredibly alarming", a response echoed by the United Nations Special Rapporteur on the Rights to Freedom of Peaceful Assembly and Amnesty International Australia.
The sentence was overturned on appeal, but Coco told the ABC podcast Saving The Franklin that the laws are a fundamental threat to the right to protest.
"With this new law that prevents us from being on a road without police approval, that is absolutely our right to protest under threat," she said.
Coco was charged under laws targeting protesters who block public roads, rail lines, tunnels, bridges and industrial estates.
For David Mejia-Canales, a senior lawyer in the Democratic Freedoms team at the Human Rights Law Centre, the laws are part of a "worrying trend" over the past decade in Australia.
"What we've seen is that as environmental activism has increased, state governments have then increasingly sought to introduce laws that explicitly criminalise that sort of activity," Mejia-Canales said.
"Tasmania, New South Wales, Western Australia and Victoria have recently introduced or proposed laws directed to curbing protest rights.
"We're seeing these really broad, ill-defined laws that have these excessive police powers and disproportionately harsh penalties."
'Wreaking havoc'
After introducing the protest laws last year, the NSW attorney-general at the time, Mark Speakman, defended them by saying that climate protests like Coco's "wreak havoc" for citizens.
"People can still have rallies outside parliament in Macquarie Street. They can go on social media. They can go on the airwaves. There are plenty of ways to protest," he said.
But for protesters like Coco, the attention gained by disruption is the point. She referenced the Franklin campaign as a precursor to the forms of direct action being seen in the climate protests today.
"One of the most important parts of [the Franklin campaign] was where they would literally go out onto those barges day after day after day and get arrested standing in the way of the destructive machinery."
More recently, climate activist groups like Extinction Rebellion and Just Stop Oil have used a range of targets for blockades and non-violent direct action, like blocking roadways or throwing soup onto classic paintings.
Unlike the Franklin River and the site of the proposed dam, those who want greater action on climate change lack a highly visible frontier on which to protest.
Coco says activists have instead chosen to target locations that maximise publicity as the world moves closer towards catastrophic climate breakdown.
"It's all about raising awareness. It's about embodying my truth and the truth of the science, which is that there's something profoundly wrong with our current trajectory," Ms Coco said.
"We need to shift gears into an emergency speed transition to zero emissions."
The new forms of direct action
New laws came into effect this month in Victoria that target activists who protest against logging in designated "timber harvesting zones", arguing that forestry workers had to be protected from the protesters' actions.
Legal organisations have raised concerns about this "worrying" trend, claiming it undermines an important right in democratic societies.
"The right to freedom of association and peaceful assembly, these are fundamental human rights that are absolutely critical in a democratic society like ours," says Mejia-Canales from the Human Rights Law Centre.
"What I would say to anyone who thinks that these things should not be allowed, is that if our right to protest and our right to assembly is going to have any value, then it is going to be a little disruptive.
"We should have a certain level of tolerance for some disruption to our everyday life if we are going to absolutely protect our right to agitate for change.
"The right to speak up publicly and draw attention to a cause … is an essential component of our democracy.
"In fact, it's how we've won our way of life, from saving the Franklin, to votes for women, to land rights for First Nations people, and we need to guard those rights very, very jealousy."
The Franklin blockade turned the debate about whether to dam the river or not into a key 1983 federal election issue, and helped elect the next Prime Minister Bob Hawke on his promise to stop the dam.
Christine Milne's experience at the Franklin blockade helped pave the way for a career in environmental politics, and she led the Greens party in Tasmania and federally before retiring from parliament to continue activism.
"The politics would never have happened without people putting their bodies on the line," she says.
"It wouldn't have happened without that activism.
"And that's why we have to ensure people always can put their bodies on the line."
Join Jo Lauder as she investigates the biggest environmental movement Australia has ever seen in Saving the Franklin, a new series of the history podcast Dig.
