New research by Vrije Universiteit Brussel (VUB) shows that globally up to 560 million children aged 0 to 9 years old (43% of all children in this age group) are living through at least one additional month (30 or more days) of heat stress per year due to human-induced climate change. This exposure outpaces any other age group and is nearly triple the 190 million people (30%) aged 60-69 experiencing this additional health threat. Children are therefore already facing disproportionately high levels of dangerous humid heat caused by human-induced climate change, with exposure expected to grow under further warming. Under projected climate change scenarios of 1.5°C and 2°C of global warming, which are extremely likely to be breached if countries continue current policies, the number of children affected by an additional month of dangerous heat is expected to increase to 620 million (49%) and 650 million (59%) children aged 0-9, respectively. The study, published today in Science Advances by an international team of researchers led by the VUB, is the first-ever analysis to quantify how heat exposure directly linked to climate change affects different age groups globally, both now and in the near future. The researchers combined population data with state-of-the-art climate models and attribution science that identifies the role of climate change in extreme weather events. The cutting-edge study highlights that the health risks of climate change are already here today and are unequally distributed across generations and geographies.
Key findings include:
● Current impacts: Climate change has almost tripled the number of children exposed to at least 5 months (150 days) of total heat stress globally from 120 million (9% of children today) in a world without climate change to 350 million children (27%) today. This is nearly three times as many as the number of adults aged 60-69 exposed to at least 5 months of total heat stress (120 million or 18%).
● Geographic disparity: The largest increases in humid heat due to climate change are occurring in tropical regions and poorer countries, where populations are younger, and more children are therefore affected. South Asia, Southeast Asia, and West Africa are the regions with the highest number of children exposed to dangerous heat stress today.
● Future scenarios:
Children will remain disproportionately exposed compared to all other age groups, regardless of populations ageing globally:
○ In a 1.5oC world: 620 million children (49%) aged 0-9 are projected to experience at least one additional month of heat stress per year, and 390 million (31%) are projected to experience at least 5 total months of heat stress.
○ In a 2oC world: 650 million children (59%) aged 0-9 are projected to experience at least one additional month of heat stress per year, and 420 million (37%) are projected to experience
at least 5 total months of heat stress.
Excessive heat disrupts the human body’s normal functioning, aggravates underlying diseases, and can lead to serious complications such as heatstroke, dehydration, and organ failure. Dangerous heatwaves are being made more frequent and intense by climate change, primarily driven by the burning of fossil fuels like oil, coal, and gas. The study focuses on humid heat, which is more dangerous than dry heat because it impedes the body’s ability to sweat to cool back down, leading to dangerous levels of heat stress. Children are highly vulnerable to extreme heat because their bodies heat up faster than adults, they sweat less efficiently, and they rely on adult care. Overheating can cause severe health risks, including dehydration and dangerous heatstroke, as well as impacts on learning and cognitive development. The findings come at a critical moment for climate policy. The ongoing energy crisis has further highlighted the risks of depending on fossil fuels, and 2026 has already seen some of the most severe heatwaves ever recorded, some virtually impossible without the influence of climate change.
Rosa Pietroiusti, Lead author of the study and PhD researcher at VUB, said:
“Climate change is already causing hundreds of millions of children to suffer from dangerous heat worldwide, posing severe risks to their health. Children in developing countries face disproportionate exposure to climate extremes now and into the future, despite contributing the least to historical greenhouse gas emissions. At the same time, poverty, inadequate housing, limited access to cooling, and overstretched healthcare systems leave many children with few ways to protect themselves from the heat.” “Young people are not only the most affected by climate change — they are also at the forefront of tackling it, from leading the Fridays for Future school strikes to bringing important climate litigation cases to national and international courts. We need governments to step up and take serious and immediate action to heed young people’s calls for climate justice.”
Wim Thiery, Senior author of the study and Professor at VUB, said:
“Our research highlights that to protect future generations, policymakers must urgently and drastically cut fossil fuel emissions and limit warming in line with the Paris Agreement to stop the most catastrophic impacts of the climate crisis.” “At the same time, a huge increase in the flow of climate finance to developing countries and targeted adaptation measures around the world such as heat action plans and improved public health systems will be essential to protect younger generations in a rapidly warming world.”
A full press package can be found at this link containing: the press release in other languages, the research article, tabled results at the region/country-level and a supplementary document detailing results for countries/regions with high numbers of children impacted, additional citations from NGOs and children, an illustrative figure.
Science Advances
Age-specific exposure to human-induced increases in humid heat
26-Aug-2026