"World War III is well and truly underway. And we are losing," writes environmental activist Bill McKibben, so when Malcolm Turnbull implied that the insurgency that demolished his government was based on climate ideology, what lessons are there for Scott Morrison?

As a child in Britain during WWII, I lived in a street of mothers and children. Every father was away fighting. Each house and garden was surrounded by a metal palisade fence.

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One morning the fences were gone, mother was delighted. Then a horse and cart came and took away every metal cooking pot and pan, some treasured, but mother smiled at her sacrifice. It was difficult for me to understand.

She had responded to the call from Lord Beaverbrook, Minister of Aircraft Production, for the women of Britain to: "Give us your aluminium. … We will turn your pots and pans into Spitfires and Hurricanes."

Grey sky blanketed my childhood, each day clouded by the expectation of a knock on the door by the telegram man. There was poverty and hunger but paradoxically it was a happy time, food was shared and houses were open to all.

Families rushed to harvest hay, to clear the snowy roads in winter, to house the bombed families and to "make do and mend" with clothes and shoes.

Britain was a united and cohesive community. Young and old worked daily in small ways for the common cause. But most importantly, in the free world, two countries — Britain and the US — had leaders in Winston Churchill and Franklin D Roosevelt who could explain the need for duty and sacrifice.

Their like is yet to emerge today, and indeed the Western world is bereft, perhaps apart from French President Emmanuel Macron, who explained to Congress and the American people that secure borders are irrelevant to this threat, and all of us are world citizens needing to act in concert. "There is no Planet B," he said.

He challenged Malcolm Turnbull to show leadership on climate change.

Prime Minister, please call for a personal briefing by Australia's leading climate scientists. ( ABC News: Nick Haggarty )

US and Australia trading ideology for human lives

Two of the world's highest per capita carbon emitters, the United States and Australia, have deserted the trenches of WWIII by trading ideology for human lives and health.

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The US response to the climate threat has been withdrawal from the Paris agreement and a full-frontal attack on the US Environmental Protection Authority, a national defence against climate change, pollution and ill-health — as irrational as if the Germans had demolished their "Siegfried Line" of WWII.

As a doctor, I know that they will compromise the health of children and families from relaxation of pollution standards on coal-fired power stations and from weaker fuel standards. Their actions are an attack on all humanity and thereby the US has abandoned world leadership.

Australia's response to climate change is devious; under the guise of action, the transition to renewable energy has been carefully modulated to maintain coal. Policy was corrupted by deference to a party clique of climate deniers who proudly named their group after Australia's most illustrious WW1 general John Monash, and were deaf to his descendants pleading for his name to be removed.

Like the US, Australia is failing to save the lives of its citizens by prolonging the life of polluting coal-fired power.

As a wealthy, technological nation failing to assist others in a transition from fossil fuels, and soon to become the leading exporter of coal and gas in the world, Australia has failed to temper its quest for prosperity and serve the needs of humanity.

Humanity lives in one atmosphere

Both the United States and Australia must understand that humanity lives in one atmosphere and all must act decisively and collectively to preserve the common and finite resources of land, sea, air, biodiversity and fresh water necessary for health and wellbeing.

Leadership is the ability to explain this to voters and to caution that any hope of future prosperity depends upon collective action.

But leadership by an emerging Churchill or Roosevelt is much more difficult than in WWII. Leadership will need to explain the pots and pans needing to be sacrificed today.

Mr Churchill's stirring "We shall fight on the beaches, we shall fight on the landing grounds", an easily understood message of WWII, has to become equally inspirational on changes in lifestyle, personal commitment to curbing rampant consumerism, energy transition, efficient recycling, modifying diet and conserving biodiversity and, ultimately, a sharing of finite resources and economic sacrifice.

These endeavours will also need to be accepted by the corporate empires that pollute and frequently enrich themselves from environmental capture and exploitation.

They must recognise that their survival also depends on climate action.

Mr Morrison, think of your lovely young children

But most importantly leaders must understand complex problems.

Prime Minister, doctors wish you well in your endeavours; your visit to drought-riven states is an excellent start. Our suggestions relate to the two most important people at your investiture, your lovely young children.

Please study the collective action plan so badly needed (a report co-authored by leading medical scientist Fiona Stanley) to avoid burning their futures in a hot, hungry, stormy and resource-conflicted world.

And please call for a personal briefing by Australia's leading climate scientists on these and related issues.

Dr David Shearman is the honorary secretary of Doctors for the Environment Australia and Emeritus Professor of Medicine at Adelaide University.