More than 270 scientists have signed an open letter to Australia's leaders calling on them to abandon partisan politics and take action on climate change.

Key points: The scientists have expertise in climate, fire and meteorology

The scientists have expertise in climate, fire and meteorology They are calling for urgent action to reduce Australia's greenhouse gas emissions

They are calling for urgent action to reduce Australia's greenhouse gas emissions The scientists warn the impacts of climate change are coming faster, stronger and more regularly

The letter comes as Parliament sits for the first time this year and amid Australia's ongoing bushfire crisis.

The scientists, who have expertise in climate, fire and meteorology, are calling for urgent action to reduce Australia's greenhouse gas emissions and for Canberra to engage constructively in international agreements.

"The thick, choking smoke haze of this summer is nothing compared to the policy smokescreen that continues in Australia," University of NSW climate scientist Katrin Meissner said in a statement on Monday.

"We need a clear, non-partisan path to reduce Australia's total greenhouse gas emissions in line with what the scientific evidence demands, and the commitment from our leaders to push for meaningful global action to combat climate change."

The scientists warned an increase in bushfires was just one part of a deadly equation that suggested the impacts of climate change were coming faster, stronger and more regularly.

Heatwaves on land and in the oceans were longer, hotter and more frequent, they said.

Australian National University climate scientist Nerilie Abram said the letter was the product of scientists' despair as they witnessed the deadly fire season unfold.

"Scientists have been warning policymakers for decades that climate change would worsen Australia's fire risk and yet these warnings have been ignored," Professor Abram said.

Separately, Oxfam said the Government must demonstrate it had fully grasped the lessons of this "horrific" bushfire season.

"In spite of the scientific evidence and the extreme weather we're living through — bushfires, hailstorms and drought — the Government still hasn't joined the dots and taken action to tackle the root causes of the crisis," Oxfam chief executive Lyn Morgain said in a statement.

She said Australia must dramatically strengthen emissions reduction targets and move beyond fossil fuels.

"The Government's narrow-minded focus on adaptation and resilience simply does not go far enough," she said.

She said Australia could wield great authority and leverage globally if it changed its policies.

"If we led by example and immediately strengthened our own emissions reduction commitments, and if we linked our own crisis with those escalating around the world, we could be a great catalyst for stronger international action," she said.

AAP/ABC