The Australian Academy of Science has become the latest major institution to offload its fossil fuel investments.

Australia’s leading science institution says it cannot maintain investments in an energy source and resource industry that is unsustainable, and will continue to take a heavy toll on people, society and the natural environment.

Australian Academy of Science president Professor Andrew Holmes told a climate science conference in Hobart this week that the group has withdrawn all its direct investments in fossil fuel companies.

He urged the scientists in attendance to be “truth tellers” that fight the “scientific fallacy” in the public debate on environmental and energy policy.

The divestment extends to direct investments only, and will not apply to managed funds and listed investment companies.

The Australian Academy of Science has joined the growing fossil fuel divestment movement, which is gaining serious traction around the world.

The movement pressures institutions to withdraw investment in coal, oil and gas companies because of their contribution to climate change.

The most significant member of the movement so far has been Norway’s $900 billion sovereign wealth fund – a fund built from the profits of nationalised oil fields - which withdrew from stocks dominated by coal earlier this year.

Australian institutions including the Australian National University, the Uniting Church peak body and the Newcastle City Council are making similar moves.

Also this week, the Melbourne City Council was called to consider a motion ruling out any future direct financial move into fossil fuels – despite it already having no such investment.

The Council is considering asking its default super fund to offer a fossil-free option as well.

While the Academy of Science’s move will not quite bring the industry to its knees, the multi-million-dollar divestment does add to the momentum of the forward-looking financial shift.

In his speech to the Greenhouse 2015 conference, Professor Holmes said it was about showing leadership.

“This is a small step that the academy can take, but it is a step towards discharging our responsibility as scientists, and as leaders in society,” he said, according to Fairfax reporters.

While Dr Holmes concedes that divestment is a difficult political issue, and the academy considers itself apolitical, he said it had solid “rational grounds”.

“Is the value that could be derived from fossil fuel activities sustainable in the long term?” he asked.

“Certainty not from the view of the Earth system, and probably not financially either.”

More broadly Professor Holmes said that if humanity is to meet the “grand challenge for our modern age”, scientists must enter the public debate, moving “beyond being truth seekers” to become “truth tellers”.

He said it was clear that current and future generations rely “on [scientists] not to shirk our responsibilities”.

“We must not leave the duty of leadership to those who seek only power and glory”.

“We must ensure that we have a hand in shaping the future so it is fit for our children, and their children.”

The Academy of Science is a fairly conservative, non-activist, organisation. However, its website does feature a recently updated “Question and Answer” outlining document on climate change.