Age-specific exposure to human-induced increases in humid heat.

Children are particularly vulnerable to climate change impacts and will face intensifying effects of climate change during their lifetimes. Here, we show that children already face disproportionate exposure compared to older generations, as many live in regions hit the hardest by escalating humid heat stress. Combining demographic data with a global grid-scale attribution framework, we find that, at present-day warming levels, 2.8 to 3 times more children aged 0 to 9 years than adults aged 60 to 69 years are exposed to at least 20 additional heat stress days attributable to anthropogenic climate change based on both reanalysis (3.0 [3.0 to 3.1]) and climate models (2.8 [2.4 to 3.0]). On average, children experience 9 to 10 more attributable heat stress days than people aged 60 to 69 years (reanalysis: 9 [6 to 9]; models: 10 [6 to 13]), and this difference is likely conservative as children spend more time outdoors. This intergenerational disparity persists as overall heat stress escalates under global warming of 1.5° and 2°C, highlighting the need for mitigation and adaptation policies to protect children from heat-related health risks.