Climate change as a modifier of paediatric lung-function trajectories

Lung function follows a life-course trajectory, rising through childhood and adolescence to a peak in early adulthood; a low peak is associated with later COPD, cardiovascular morbidity and premature mortality. Childhood and adolescence are therefore the key periods during which adult respiratory reserve is built. Climate change is relevant to paediatric respiratory health not only because it triggers acute symptoms, but because it intensifies, prolongs and reschedules exposures already known to affect the developing lung, including heat, air pollution, wildfire smoke, aeroallergens and indoor damp. In this mini-review, we use lung-function trajectories as the organising framework and examine how climate-sensitive exposures may shift them downwards through three developmental pathways. First, early developmental disruption, including gestational air pollution and ambient temperature, may lower the starting point of the trajectory through fetal growth restriction, preterm birth and possibly direct effects on developing airways. Second, sustained exposure to air pollution, heat and indoor dampness across childhood and adolescence may impair postnatal lung growth and reduce lung-function growth and the peak attained. Third, climate-sensitive triggers increasingly precipitate exacerbations followed by incomplete recovery, particularly in asthma and cystic fibrosis, resulting in exacerbation-related step-down events. Crucially, these trajectories are not fixed; evidence that improving air quality accelerates lung-function growth shows that respiratory reserve can still be protected. We translate this trajectory-centred evidence into practical, climate-aware paediatric care, shifting the focus from short-term symptom prevention to preserving the lung-function reserve children carry into adulthood.