Mapping the global health burden of climate-sensitive exposures: a systematic scoping review

Abstract Background Climate change is an increasing determinant of morbidity and mortality worldwide. However, the health burden attributable to climate-sensitive exposures remains poorly quantified and inconsistently reported across the existing literature. This lack of systematic evidence limits the ability of policymakers and health systems to allocate resources efficiently, design targeted interventions, and implement effective adaptation strategies. Methods We conducted a systematic scoping review following the PRISMA-ScR guidelines to map and synthesize available global evidence on the health impacts of climate-sensitive hazards, including heat, temperature variability, extreme weather events, and air pollution. Peer-reviewed studies published up to November 2024 were identified through searches in Scopus, PubMed, Embase, and Web of Science. Eligible studies were charted by exposure type, health outcome, study design, and geographic region. The review protocol was pre-registered in PROSPERO (CRD42023421873). Results Of the 15,538 records screened, 199 studies met the inclusion criteria. Evidence was most consistent for heat exposure, which showed strong associations with all-cause, cardiovascular, and respiratory mortality. Across 15 disease categories—including mental health, infectious, endocrine, and neurological disorders—exposures sensitive to climate change were associated with increased morbidity and mortality risks. However, the available evidence base was heavily skewed toward high- and upper-middle-income countries, with over half of the studies conducted in China. Evidence gaps were identified for undernutrition, injuries, disabilities, and non-fatal outcomes, particularly in low- and middle-income countries. Heterogeneity in exposure definitions, outcome, and regional data availability limited comparability across studies. A selective meta-analysis of comparable studies yielded pooled attributable fractions of 1.18% (95% CI: 1.01–1.37) for all-cause, 2.15% (1.54–2.88) for cardiovascular, 3.08% (2.17–4.15) for respiratory, and 2.71% (1.85–3.73) for stroke-related mortality due to heat. Additional climate-sensitive exposures and outcomes were not comparable and therefore could not be pooled. Conclusions Climate-sensitive exposures are associated with a substantial health burden as reflected in the available global literature, with the strongest evidence originating from high-resource settings. Findings from this scoping review highlight the urgent need to enhance climate health surveillance systems in underrepresented regions, harmonize exposure and outcome metrics, and strengthen the integration of health evidence into national adaptation strategies and climate finance mechanisms. Addressing these evidence and infrastructure gaps is critical for informing equitable, data-driven adaptation planning, public health preparedness, and downstream loss-and-damage policy discussions.