First systematic review and meta-analysis of the risk magnitude of climate-change effects on child health

Abstract Children are significantly more vulnerable than adults to climate-related health threats, but studies examining how climate change affects human health have been mainly descriptive and lack an assessment of the magnitude of health effects children face. In this systematic review and meta-analysis, we searched online databases PubMed , Medline , Embase , and Web of Science for observational studies published up to 5 January 2023 following PRISMA guidelines. We included studies if they explored climate variables/events and measured a quantifiable child-health outcome. We extracted data from published reports for a meta-analysis where we standardised effect sizes and compared them among different groupings of climate variables and health outcomes. We evaluated each study individually and aggregated and analysed relevant qualitative and quantitative data. We identified 1301 articles from the four large databases in our systematic literature review, of which 163 studies were eligible for analysis. We identified many relationships between climate change and child health, the strongest of which were increasing risk (60% on average) of preterm birth from exposure to temperature extremes. Respiratory disease, mortality, and morbidity were also influenced by climate changes, but to a lesser extent than preterm birth. The effects of different pollutants on health outcomes were considerably smaller compared to temperature effects, but with most (16/20 = 80%) pollutant studies indicating at least a weak effect. Most studies occurred in high-income regions, but we found no geographical clustering according to health outcome, climate variable, or magnitude of risk. We identified the following protective factors for climate-related child-health threats: ( i ) economic stability and strength, ( ii ) access to quality healthcare, ( iii ) adequate infrastructure, and ( iv ) food security. Threats to these services vary by local geographical, climate, and socio-economic conditions. Children will have increased prevalence and severity of disease due to anthropogenic climate change, and our quantification of the magnitude of expected increases is essential to plan for mitigation that will improve the health of current and future generations.