"For all those people running around saying we should abandon coal right now,what are they going to do with our electricity needs this summer if we stop all our coal fired power stations?"Mr McCormack asked.

"Yes,the discussion can be had[but] there's been a lot of hysteria around climate change. Climate change isn't the only factor that has caused these fires."

He named dry lightning strikes,arson and"self-combusting piles of manure"among the causes.

Asked why he was in his electorate and not at the RFS headquarters as acting Prime Minister,Mr McCormack said he had received a telephone briefing early on Saturday morning.

"You don't want to get in the way of these professional people doing their job,"he said."I'm doing what I can from where I am ... I've already been there this week."

Mr McCormack said Mr Morrison had expressed regret over the timing of his Hawaiian holiday and was"on his way back"and"will be back today",which was"a good thing".

"No one could have envisaged what has transpired this week ... everyone is entitled to a holiday,"he said.

He said Mr Morrison had"been getting briefings every day whilst he's been on leave".

Grattan Institute energy program director Tony Wood said the government should heed public concerns andInternational Energy Agency executive director Fatih Birol's call for Australia to "take steps in line with[its] reputation" as "a responsible country" to reduce its emissions.

"A pragmatic politician will start to say,'We have to listen to all of this,'"Mr Wood said,predicting that Mr Morrison would"start to steer the ship a bit differently"in the wake of the bushfires.

When public sentiment reached a critical tipping point,he said any"sensible government"that wanted to stay in power would"have to pay heed"to the calls for change.

Former prime minister Kevin Rudd said the Morrison government was"steadily shredding Australia's international reputation as a responsible global citizen"by"actively ... slowing down global action on carbon reduction".

"Morrison is the Prime Minister. It's about time he acted like one,"Mr Rudd said.

Australian Industry Group chief executive Innes Willox said"any rational observer"would conclude that"Australia has not handled climate and energy policy for the past 15 years".

"The time has come for governments and industry,along with key sectors like transport and agriculture,to knuckle down to calmly and sensibly work towards our 2050 Paris goals."

Mr Willox said no matter what had caused the bushfires,they along with the drought"should make these objectives front of mind".

Mr McCormack said he contacted NSW Premier Gladys Berejiklian on Saturday morning to discuss further federal assistance to the state's fire fighting effort.

He extended his sympathies to the families of Geoffrey Keaton and Andrew O'Dwyer,the firefighters killed while battling a blaze south-west of Sydney on Thursday night.

"Our hearts go out to the Keaton and O'Dwyer families for the loss of Geoffrey and Andrew,two young men in the prime of their life - in their 30s,with young children - who have lost their lives volunteering so that others can save their properties and potentially save their lives.

"Geoffrey and Andrew were mates and their spirits will always be with us."