The findings show that 83% of today's five-year-olds will experience "unprecedented" levels of extreme heat — exposure to temperature extremes that would be virtually impossible in a world without human-driven climate change.
The study lays bare the human cost of governments failing to honour the Paris Agreement target of limiting global heating to 1.5°C. Instead, current climate plans put the planet on course for a rise of 2.7°C — and if existing pledges continue to fall short, the world is heading for 3.1°C of warming by the end of the century.
"This is a crisis children didn't create, but one they are living with every day," said Inger Ashing, CEO of Save the Children International. "From heatwaves that threaten their health and education to floods and crop failures, the impact is devastating — and unjust."
Climate extremes shaping childhoods
The report's projections show that limiting warming to 1.5°C could shield 38 million children from lifetime exposure to extreme heat. Millions more could be spared from the worst impacts of flooding, crop failures, drought and cyclones.
But under current policies, climate extremes will become a defining feature of life — not just for children in low-income countries, but globally.
Even adults born in 1960 are now expected to experience unprecedented heat exposure in regions including the Americas, Australia, the Middle East and Africa. But children, especially those born in 2020, will face "far greater intensity and frequency" of heatwaves, the report warns.
On the frontlines: voices from Brazil and Vanuatu
Denise, a 16-year-old from Brazil, lost her home to historic floods last year. "It really affected me mentally, and academically too," she said. "I missed two months of school. My grades dropped. Catching up was incredibly difficult."
Haruka, also 16, from Vanuatu, has witnessed three major cyclones in one year. "We don't even bother fixing the ceiling anymore," she said. "The destruction never stops. Most people don't realise it's not just nature — we're suffering for a crisis we didn't cause."
Children living in the Global South and in poorer communities are bearing the brunt. Their families are least equipped to recover from climate shocks and already face heightened risks from disease, hunger and malnutrition.
A call for urgent, child-focused climate action
Save the Children is calling for rapid and equitable climate action — beginning with a full phase-out of fossil fuels and stronger commitments from high-emitting countries. It also urges governments to centre children in climate strategies and future Nationally Determined Contributions (NDCs).
That includes scaling up climate finance that prioritises core services like healthcare, education, clean water, child protection and social safety nets.
"There's still hope but only if we act decisively," Ashing said. "This must be a turning point. Children can't afford another decade of broken promises."