As human-driven climate change advances, many adults fret about the losses of livelihoods, houses and farms that may result. Children fret about their parents’ worries and about information they hear, but do not really understand about the world’s climate and perhaps about their own futures. In chronically worried or anxious children, blood cortisol levels rise and adverse changes accrue in various organ systems that prefigure adult-life diseases. Meanwhile, for many millions of children in poor countries who hear little news and live with day-to-day fatalism, climate change threatens the fundamentals of life—food sufficiency, safe drinking water and physical security—and heightens the risks of diarrhoeal disease, malaria and other climate-sensitive infections. Poor and disadvantaged populations, and especially their children, will bear the brunt of climate-related trauma, disease and premature death over the next few decades and, less directly, from social disruption, impoverishment and displacement. The recent droughts in Somalia as the Indian Ocean warmed and monsoonal rains failed, on top of chronic civil war, forced hundreds of thousands of Somali families into north-eastern Kenya’s vast Dadaab refugee camps, where, for children, shortages of food, water, hygiene and schooling has endangered physical, emotional and mental health. Children warrant special concern, both as children per se and as the coming generation likely to face ever more extreme climate conditions later this century. As children, they face diverse risks, from violent weather, proliferating aeroallergens, heat extremes and mobilised microbes, through to reduced recreational facilities, chronic anxieties about the future and health hazards of displacement and local resource conflict. Many will come to regard their parents’ generation and complacency as culpable.