Almost 100 homes, cabins and caravans were destroyed when a ferocious firestorm ripped through the picturesque seaside town of Tathra in NSW, while in Victoria weekend fires claimed up to 18 homes and 42 sheds.

David Bowman, a professor of environmental change biology, says analysis of recent events shows fire seasons are longer globally.

"Joining the dots, this is consistent with climate change," the University of Tasmania academic told AAP on Monday.

"This is the new normal now - we need to get our heads around this.

"This has some really significant implications for people living in flammable environments because it means you can't put your guard down.

"You can't think summer has ended and say, 'Phew we dodged a bullet'."

The classic example was the 2017 season in California where fires raged right through the northern autumn, Prof Bowman said.

High temperatures, dryness and incredible winds are combining to create "crazy fires" which burn uncontrolled through the night.

The biologist said increased fire activity had been predicted by climate scientists and, while political leaders had struggled to deal with an abstract threat, the danger was now very real.

"It's a fact," he said, adding debate now needed to focus on making communities safer.

People would still live in bushland areas but there would need to be "buffers" around settlements such as parklands, community gardens and golf courses.

"Having houses nestled in bushland ... those days are numbered," Prof Bowman said.

Australia Greens leader Richard Di Natale says the federal government has been slowing the transition to renewable energy "and Australians are bearing the brunt of their failure".

"We are seeing climate change in our everyday lives have an impact on the risk of bushfires to our communities," Senator Di Natale told parliament on Monday.

"We can't any longer be complacent about bushfires once the end of summer comes around."

Prime Minister Malcolm Turnbull accused the Greens of politicising the disaster. He said no one particular event could be attributed to climate change.

"We are the land of droughts and flooding rains. We're the land of bushfires," he told reporters in Bega.

"Nature hurls her worst at Australians - it always has and always will. We have an environment which has extremes."

The president of the Australian Council of Environmental Dean and Directors says bushfires "well into autumn" will become increasingly common.

"Given our weak efforts to reduce emissions globally - and especially in Australia - we will increasingly need to plan for catastrophic events and pick up the pieces following such events," Associate Professor Grant Wardell-Johnson from Curtin University said in a statement.

"A move from burying heads in the sand towards adaptation to climate disruption is well overdue."

Australian Associated Press