Climate change and harmful marketing are jeopardising the future of every child around the world — and Australia is failing to create an environment fit for future generations.

Key points: Landmark report finds all children are under threat from climate change and poor health

Landmark report finds all children are under threat from climate change and poor health Australia performs well on child health global index, but lags on carbon emissions

Australia performs well on child health global index, but lags on carbon emissions WHO Director-General says report must be a 'wakeup call'

That's according to a major international report released on Wednesday by the World Health Organisation (WHO), United Nations Children's Fund (UNICEF) and leading medical journal, The Lancet.

The report, titled A Future for the World's Children?, warns climate change, conflict and harmful marketing practices that drive obesity threaten the health and future of children worldwide.

"Despite improvements in child and adolescent health over the past 20 years, progress has stalled, and is set to reverse," said Helen Clark, former New Zealand Prime Minister of and co-chair of the Commission.

Researchers analysed data from 180 countries and compared performance on child survival and wellbeing, based on health, education, nutrition, equity and sustainability measures.

Australia ranked 20th in the global "child flourishing" index for its performance on child survival. But it lagged on sustainability, coming in at 174 — putting it among the top 10 worst greenhouse gas emitters.

WHO director-general Tedros Adhanom Ghebreyesus said the report must be a wake-up call for countries to invest in child health and development, and "build a future that is fit for children".

"This report shows that the world's decision makers are failing today's children and youth: failing to protect their health, failing to protect their rights, and failing to protect their planet," he said.

CO2 emissions threaten kids' futures

The report found that no country is adequately protecting children's health, their environment and their future in the face of "environmental and existential threats".

Children in Norway, Korea and the Netherlands were found to have the best chance of good health, education and nutrition, while children in Central African Republic, Chad and Somalia faced the worst odds.

By 2030, 2.3 billion people, many of whom will be children, are projected to live in fragile or conflicted regions of the world. ( Getty Images: Julia M Free )

While wealthy countries tended to do better on child health and development outcomes, their disproportionately high carbon emissions threatened the future of all children.

"Every child worldwide now faces existential threats from climate change and commercial pressures," Ms Clark said.

"Countries need to overhaul their approach to child and adolescent health, to ensure that we not only look after our children today, but protect the world they will inherit in the future."

Australia's per capita carbon dioxide (CO2) emissions are among the highest in the world, and the WHO estimates by 2030, the nation's emissions will be 524 per cent above our global target.

If global warming exceeds 4 degrees Celsius by the year 2100 in line with current projections, devastating health consequences are predicted, due to heatwaves, malnutrition and the proliferation of diseases like malaria and dengue.

Liz Hanna from the Climate Change Institute at the Australian National University (ANU) said Australia's poor ranking on climate scores was evidence the country had "lost its way".

"Decades of wilful neglect of the environment and the erosion of compassion have transformed the lucky country to an international laggard that is failing its children," Dr Hanna said.

"By taking our natural advantages for granted, Australia is squandering its opportunities to secure a safe and healthy future for our children."

Harmful marketing targeting kids

In addition to the threat of ecological degradation and climate change, the report warns of the harms of marketing fast food, sugary drinks, alcohol and tobacco to children.

Evidence suggests children in some countries see as many as 30,000 television advertisements in a single year, while young people's exposure to vaping advertisements increased by more than 250 per cent in the USA over two years.

"Children around the world are enormously exposed to advertising from business, whose marketing techniques exploit their developmental vulnerability and whose products can harm their health and wellbeing," the authors wrote.

Peter Sly from the University of Queensland (UQ), who co-authored the report, said it was clear industry self-regulation was not working.

"The various governments and regulators responsible need to impose restrictions that truly protect children," said Professor Sly, director of UQ's Children's Health and Environment Program.

"We did it for tobacco, so why not alcohol and gambling?"

VicHealth chief executive officer Sandro Demaio agreed that more needed to be done to protect the health and nutrition of young people.

"We know roughly one in three young people across Australia are already above a healthy weight, and that's at the age of four years old, before they even get to school," Dr Demaio said.

"Those children will likely never achieve a healthy weight across their life course, but it's completely preventable through providing opportunities … and making it affordable for all families to access good food."

Dr Demaio said tackling climate change was also necessary for the future health and wellbeing of young people.

"Otherwise what we're basically doing is leaving young people with ill health and a climate mess to clean up long after we're gone. And that's unconscionable."

Calls for global action

The authors of the report called for a new "global movement" for children that includes massive reductions in CO2 emissions, improved policy and investment for child health and rights and tighter controls on commercial marketing.

An accompanying editorial, also published in The Lancet, said the health and wellbeing of children depended on overcoming challenges that threatened to undermine the progress and successes of the past two decades in child health.

"The climate emergency is rapidly undermining the future survival of all species, and the likelihood of a world in which all children enjoy their right to health appears increasingly out of reach," the authors wrote.

"The task at hand is urgent and immense ... there can be no excuses, and no time to lose."