Authorities across Australia were warned by Home Affairs months before the crisis that last summer's bushfire season would be dire.
Director-general of the department's emergency management branch Robert Cameron provided preparedness briefings alongside Defence officials and Bureau of Meteorology staff.
"Last year's forecast was dire and was characterised as dire in every instance," Mr Cameron told a Senate inquiry.
"In fact, the language I used in pretty much every briefing I gave ahead of last summer was ... I talked about 'dire fire'."
The briefings to state emergency management services were completed by October.
Decisions made by the federal government before, during and after the devastating summer bushfires are under scrutiny by the Senate inquiry, which began public hearings on Wednesday.
The Black Summer fires killed 33 people, destroyed more than 3000 homes and razed close to 13 million hectares.
The inquiry is looking at what lessons can be learnt from the fires, including preparation and planning, response and recovery efforts.
Mr Cameron said the link between climate change and severe weather had been part of Home Affairs briefings for some time.
Bushfire and Natural Hazards Cooperative Research Centre chief Richard Thornton said some parts of Australia may not be suitable to live in in the near future.
The research centre's funding comes to an end in June next year.
Department of Prime Minister and Cabinet secretary Phil Gaetjens said the department didn't brief Scott Morrison directly when he was overseas on holiday in Hawaii, but information was passed on to the prime minister's office.
Mr Morrison travelled to Hawaii in mid-December during the bushfires and came back early following community outrage over his absence.
Greg Mullins, representing Emergency Leaders for Climate Action, said the group chased meetings with Mr Morrison last year before the deadly bushfire season to brief him on climate change risks.
The former NSW fire chief said he and the other members held their tongues while in their roles.
"I know, from my own experience and other members of ELCA, in a sense we self-censored because we knew what would be acceptable and what would not, to certain political masters," he said.
"And if you went outside those bounds, life could be made very unpleasant for you."
Liberal senator James Paterson then asked: "So do you think the fire chiefs are gagged in some way?"
"Yes," Mr Mullins replied.
He also said the window for safely conducting hazard reduction burns has narrowed over recent years because the fire season has become longer.
Australian Associated Press