The 29-year-old philosophy graduate is the ACT Environmentalist of the Year for his leadership in the ANU's decision to partially divest from fossil fuel companies. Conservation Council ACT executive director Clare Henderson said the council recognised that the work of Fossil Free ANU was a group endeavour.

"However without Tom's quiet, ongoing persistence and strategic approach going back to 2013, the Australian National University would not have started the process of divesting from fossil fuels," Ms Henderson said. "Fossil Free ANU has been at the forefront of the divestment campaign and an inspiration to many."

Mr Swann arrived in Canberra 10 years ago from Sydney, where he grew up. He studied advanced philosophy at the ANU, attended many public lectures on climate change and realised society wasn't taking it seriously. "I managed to become a campaigner at GetUp! and organiser at the 2010 election,"' he said.

In 2011 environmentalist activists in the Northern Rivers region in NSW discovered the ANU was investing in coal seam gas company Metgasco, and asked the ANU's environmentalist group that Mr Swann belonged to what it was going to do about it.

Ian Young, the university vice-vhancellor newly arrived to tackle a difficult campus re-structure, suddenly had a fresh spot fire to attend after the outraged ANU students sent him a detailed email of their concerns, and began campaigning on campus.

The ANU said it would divest from Metgasco, but students later discovered that while the ANU had pulled out of Metgasco, it was buying up in another coal seam gas company, Santos, and swung the campaign focus to hypocrisy. The ANU's council realised they had to do something, which led to the university's responsible investment policy.

Ms Henderson said that when then Prime Minister Tony Abbott and Treasurer Joe Hockey, and large corporates attacked the ANU's decision to divest, Mr Swann became a spokesman. "It was a David and Goliath scenario and Tom stepped up and delivered the divestment story with rigour, passion and professionalism. It was a big challenge well met."

Mr Swann said that as the controversy grew, the Australian Financial Review wrote 53 stories, 12 of them on front pages, and more Abbott government cabinet ministers weighed in, while the ANU struggled.

From 2011 to 2015 students came and left the ANU's small environmentalist collective, yet its fossil free campaign became the longest running in Australia. Mr Swann was there for the duration. "The ANU will put that on their marketing material eventually, not yet, and I'll be happy to do it. Happy to stand there for the photo," he said.

"The ANU was lucky so many people believed in their right to do this, they did a poor job explaining themselves, they got thousands of emails of support. It was not all negative, there was huge support. I still hear people say they are really proud of the ANU as a result, it was a real morale booster in a lot of ways. "

Still, going against the prime minister and being a target in the business media was intense. "It was scary actually to think you have such powerful people looking over who you are, what you say and being willing to try and trip you up," Mr Swann said.

"I got really tired but it was exciting, because we were making history, this was something that put divestment, ethical investment on the top tier of the national, political discussion. It was a watershed moment."

Other universities in Australia still needed to catch up with universities overseas, Mr Swann said. The minerals lobby would continue to fight, framing the debate on morale grounds that coal is good for humanity, but more people and organisations would continue to question the need to dig coal from the ground.