The health and future of every child in the world is under threat from degrading environments, climate change and "harmful" marketing, a report has warned.
Analysis by the World Health Organisation (WHO), Unicef and medical journal The Lancet says that no single country is adequately protecting children's health or environment.
It compares factors including health, education and nutrition, in a global index of 180 countries.
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The report, titled A Future For The World's Children?, says that excessive carbon emissions, particularly from wealthier countries, threaten the future of all children.
The index shows that young people in Norway, the Republic of Korea and the Netherlands have the best chance at survival and wellbeing, while the UK ranks 10th.
Children in Central African Republic, Chad, Somalia, Niger and Mali face the worst odds.
The report also highlights the threat to children from "harmful" marketing, as it says evidence suggests that children in some countries see as many as 30,000 adverts on television in a single year.
Authors said an increase in childhood obesity, which they link to marketing of junk food and sugary beverages, has "dire individual and societal costs".
To protect young people worldwide, the report has called for a new global movement driven by and for children.
Recommendations include stopping CO2 emissions with urgency, incorporating children's voices into policy decisions and tightening regulations of "harmful" commercial marketing.
Henrietta Fore, Unicef executive director, said children across the globe were having to "contend with threats that were unimaginable just a few generations ago".
"It is time for a rethink on child health, one which places children at the top of every government's development agenda and puts their well-being above all considerations," she said.
Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: "This must be a wake-up call for countries to invest in child health and development, ensure their voices are heard, protect their rights, and build a future that is fit for children."