The event runs April 3-5, with several individual sessions offered for free, including four events on Sunday, April 5, billed as "Family Takeover Events".

Festival director and founder Rosemarie Milsom readily admitted at the festival launch on Thursday night the harsh summer of Australian bushfires had weighed on her mind as she was finalising the program.

But she made the point: "Art has a role to play in a crisis".

Among the guests she chased for this year's event is Lucy Treloar, author of Salt Creek and her latest novel, Wolfe Island. In Wolfe Island, set in Chesapeake Bay in the US, the island is literally sinking into the bay.

Milsom quoted a line from the book at the launch: "what we feel is as true as what we think". It is so true, Milsom said.

Treloar will present a session of the festival entitled "All at sea", discussing the thin line between the present and a dystopian future, as described in the festival program, with Susan Wyndham.

Legendary indigenous songwriter and activist Archie Roach opens the festival on Friday, April 3, at 7.30pm at Civic Theatre with a conversation - and some music - to celebrate his memoir, Tell Me Why.

Legendary Australian writer Helen Garner will discuss Yellow Notebook, the first volume of her diaries, published in November last year, in a special event at the festival on Saturday, April 4, from 7pm at the Harold Lobb Concert Hall in The Conservatorium.

Garner will also discuss her non-fiction book, The First Stone, still controversial 25 years after it was published, with journalist David Leser in conversation on Sunday, April 5, from 1.30pm.

From the science world, geneticist David Sinclair will chat with ABC's Richard Fidler on the subject, No Time to Die. Sinclair is best known for his work on understanding why we age and how to slow its effects. He is co-founder of several biotechnology companies.

Sinclair is being shared as a guest by the Festival of Dangerous Ideas in Sydney and his talk with Fidler will be taped for Fidler's national Conversations radio program.

Other heavyweights include:

- Tim Costello, at Cessnock Performing Arts Centre on Saturday, April 4;

- writer Charlotte Wood, in conversation with Ailsa Piper, on April 4;

- Blanche d'Alpuget, discussing Bob Hawke, on April 4;

- journalist Kate McClymont, discussing the war on journalism, with Newcastle lecturer Paul Scott, on April 4, and McClymont with author Michael Robotham on Sunday, April 5, discussing Corruption, Skulduggery and Murder;

- educator John Marsden, on the art of childhood, on April 4;

- broadcast journalist Virginia Trioli, in a panel with Ruby Hamad and Jane Gilmore on female activism and "their right to rage" on April 4, and speaking about Generation F on April 5.

The festival will conclude on Sunday, April 5, with refugee Behrouz Boochani speaking via Skype from New Zealand about life after Manus Island, where he spent several years, and the impact of his award-winning memoir No Friend but the Mountains.

The Kurdish-Iranian journalist and writer was captive at the Manus Island detention from 2013 to 2017, then moved to Port Moresby and is currently in New Zealand on expired visa.

Boochani's address will be from 4.30 to 5.30pm at the Concert Hall in City Hall.

There are also several events with poetry, indigenous writers and poets and New Zealand literary figures.

Climate change comes to the fore in:

- Conservationist Tim Flannery in conversation with Scott Bevan, on April 4;

- How to Save the Planet, with Tim Flannery, Upper Hunter farmer and writer Patrice Newell and Damon Gameau, author of 2040: A Handbook for the Regeneration, on April 4, from 5.30pm at the Harold Lobb Concert Hall at the Conservatorium.