Former fire chiefs from across Australia have hit out against an “unofficial gag order” on speaking about what they say is a climate emergency.

Former Fire and Rescue NSW commissioner Greg Mullins said Australians faced a “new age of unprecedented bushfire danger”.

Mr Mullins was speaking at a joint press conference with former Queensland Fire and Emergency Services commissioner Lee Johnson, ex-Country Fire Authority Victoria chief executive Neil Bibby and former Tasmania Fire Service chief fire officer Mike Brown on Thursday.

They form part of a coalition of 23 fire and emergency leaders from every state and territory, known as Emergency Leaders for Climate Change.

“This fire season is going to go for months, so do we just simply get gagged? Because I think that’s what’s happening,” he said.

“Some people want the debate gagged because they don’t have any answers.

“It’s OK to say it’s arsonists’ fault, or that the ‘greenies’ are stopping hazard reduction burning, which simply isn’t true, but you’re not allowed to talk about climate change. Well, we are, because we know what’s happening.”

"We’re former commissioners, chief officers of every urban and rural fire service in Australia. All of us have seen conditions change, supercharging the bushfire problem & it’s all down to climate change, the burning of coal, oil & gas" – Greg Mullins @BreakfastNews pic.twitter.com/v1tc58CBeI

— Climate Council (@climatecouncil) November 13, 2019

The call comes after the catastrophic bushfires that have roared across NSW and Queensland.

Earlier, Mr Johnson said the bushfire season that has razed homes and hundreds of thousands of hectares of land was like nothing he’d seen in his decades-long career.

“I’m here for my children and my grandchildren, because I am fundamentally concerned about the impact and the damage coming from climate change,” he said.

“There’s something going on, and climate change are (sic) exacerbating the dry conditions we are all experiencing.”

Mr Mullins said this week’s catastrophic fires were exactly the type of disaster that emergency leaders and climate scientists had warned about for decades – “and summer hasn’t even begun”.

“We’d like to see Labor, the Coalition government, Greens and the crossbenchers all come together and declare a climate emergency,” he said.

“Climate change is the key reason why fire seasons are lengthening, fires are harder to control, and access to international firefighting resources like large aircraft is becoming more difficult.

“The government must respond to this urgent threat with an urgent response.”

Mr Mullins said Australia needed to “rapidly bring down coal emissions” and transition away from coal, oil and gas.

He said the group had disparate political views and experiences but was united in demanding action on climate change.

“If it’s not time now to speak about climate and what’s driving these events – when?” he said.

Mr Johnson said conditions would remain extreme through the summer without significant rain. There is no rain forecast until early next year.

“In Queensland alone … we need hundreds of millimetres of rain to bring the risk back to something like normal,” he said.

“Our conditions are very much abnormal and driven very much by what’s happening in our atmosphere, and that’s influenced by greenhouse gases.”

Climate Council chief executive Amanda McKenzie said scientists had warned of the extreme bushfire risk attached to climate change for 20 years.

The organisation released a report on Wednesday that found Australia’s bushfire season had stretched so far across the calendar year that windows for hazard reduction burns had narrowed.

It wants the federal government to develop a plan to better prepare communities, and health and emergency services across the country in the face of a rising fire danger, and phase out emissions that are fuelling climate change.

-with AAP