Miranda Gibson was an unlikely candidate to break Australia's longest running tree sit record. She'd never seen a forest until her early twenties.

Growing up in Ipswich, the shy Queenslander admits she was a "wussy kid" afraid of climbing her backyard treehouse.

In 2011, she overcame those fears and endured 449 days in the Tasmanian treetops of the Tyenna Forest.

Using a solar-powered computer, she connected with people around the world, and her activism brought attention to logging in Tasmania, culminating in a world heritage listing.

Ms Gibson still holds the record for the longest running tree sit in Australia. ( ABC RN: Mike Williams )

Putting 'bodies on the line'

Ms Gibson began to take an interest in conservation as a teenager, but it wasn't until she was at university that she discovered forest activism.

"People can go in there, put their bodies on the line and the logging literally stops," Ms Gibson said.

Her interest in conservation compelled her to fly to Tasmania during her university holidays.

"The first thing I saw was the biggest tree I'd seen, and it was cut down — it was a stump. That really hit home to me what was at stake," she said.

Over the following years, Ms Gibson returned to the Upper Florentine Valley blockade to protest logging. Eventually, she decided to move to Tasmania to protest full time.

She lived on a small wooden platform, 60 metres above the ground. ( ABC: Tony King )

Ms Gibson lived at the blockade for four years. But by the time she reached the end of her twenties she was disillusioned.

"What I saw was massive amounts of forest fall. It felt like we couldn't stop it, no matter what we did," she said.

"It was a devastating process. I was at a point where I was ready to quit. What I thought we needed was international pressure to put the nomination in and get the world heritage listing."

Living outdoors in wind, rain and snow

The idea behind Ms Gibson's tree sit marathon dawned on her after she discovered there was an internet connection in the forest scheduled for logging.

It would allow her to livestream logging to the world.

"I thought if other people see it, they'll know what's at stake — they'll know it's real," she said.

Ms Gibson stayed active using a walking machine and a yoga mat. ( Supplied: Miranda Gibson )

On December 14, 2011, she climbed up a tree onto a makeshift platform 60 metres in the air.

Ms Gibson made a promise that she would not get down until the Tyenna Forest —and surrounding areas — were protected.

The media coverage was effective, and within days the loggers moved away from the eye of Ms Gibson's camera.

People became fascinated by her story, including the logistics of her action.

"The longer I was up there, the more interest it got. People were like, 'she's really committed, or what's going on?'" Ms Gibson said.

The wooden platform wrapped around the tree, but was only a few metres long and 1.5 metres wide.

Keeping dry proved a challenge — with a see-through tarp her only protection from rail, hail, wind, and snow.

Most of the food she ate was raw, and a small walking machine kept her active.

Then, there was the question of her bathroom facilities.

"I just went to the toilet in a bucket. Nothing fancy. Then I just had some lovely, supportive ground crew who were responsible for emptying the bucket and sending it back up," she laughs.

The ground crew were critical to Ms Gibson's survival and would hike two hours over difficult terrain to bring stocks of food and water.

Her action helped get 170,000 hectares of forest world heritage listed. ( ABC RN: Mike Williams )

'I started to feel a bit forgotten'

The experience was lifechanging, but the good times were always evened out by the challenges of isolation, boredom, and the extreme conditions. For Ms Gibson, it was a constant struggle.

"I would often feel this complete sense of frustration," she said.

"I would just want to walk somewhere — or I'd just like to see something a tiny bit different, even for half an hour, just a different view."

At the one-year anniversary event she was flooded with attention.

It was at this point she realised her grand public action was defining her.

"All these people who were like 'I love you Miranda', but I was there all alone," she said.

"[It was] this weird contrast between all these people knowing me, but also only knowing one part of me.

"I just felt disconnected from my life outside this tree, and the people. I started to feel a bit forgotten.

"Eventually what I had to do was say, 'my life out there doesn't really matter right now, and just forget about it and be really present in the tree.'"

"You've just got to keep fighting"

Ms Gibson's commitment paid off.

Ms Gibson says she was forced to leave her protest because of a bushfire threat. ( ABC: Claire Todd )

In February 2013, the Australian environment minister announced a world heritage listing nomination for an extra 170,000 hectares of Tasmanian forest.

It was a big win for Ms Gibson's cause, as well as various other Tasmanian environmental groups that had fought for decades in forest wars.

Ms Gibson wanted continue the tree sit until the area was officially listed.

But one month after the announcement, a fire was lit near the tree.

"I had to stay awake so I could keep an eye on it. I could see all the trees falling into it, it was that close," she said.

While she clung on to hope it would pass, the hot and dry weather made it too dangerous to stay.

"I wasn't ready to say goodbye to the tree. I felt I was breaking that promise by getting down," she said.

A few months later, the World Heritage Committee livestreamed their decision.

"It was an absolute relief when the little hammer goes down. That's done; 170,000 hectares — including my tree — world heritage," she said.

Ms Gibson now works as a school teacher in Melbourne. ( ABC RN: Mike Williams )

Ms Gibson is satisfied her personal sacrifices were worth it.

But it wasn't the end of the fight.

In 2014, the Federal Government attempted to have 74,000 hectares of the forest delisted. Ultimately, the government's bid failed.

However the moment was symbolic for Ms Gibson, who believes logging in Tasmania will always be contentious.

"You've just got to keep fighting, there's still a lot of forests that need protecting."