Two decades of climate change and its impact on emergency department presentations in the Australian Capital Territory: Past trend and future projection

Objective: The objectives of this study were to explore health impact of climate change over the last two decades in the Australian Capital Territory and to project future changes under climate change. Methods: A time series design was used to assess temperature increases due to climate change and emergency department presentations. Results: A total of 1,442,354 emergency department presentations occurred, with 2.49% of emergency department presentations attributed to heat and 4.00% attributed to cold. Future projections indicated heat-attributable fraction will increase to 2.72% and cold-attributable fraction will decline to 3.21% by the middle of this century. The younger age group exhibited highest relative risks from both heat and cold, the middle age group was particularly sensitive to heat, while older adults were most vulnerable to cold. Conclusions: Heat and cold contribute to increased emergency department presentations, with distinct age-specific vulnerabilities to temperature extremes. Projections indicate rising health burden associated with non-optimal temperatures, primarily driven by increasing heat-attributable fraction and concurrent decline in the cold-attributable fraction. Implications for public health: These findings highlight the urgent need for region-specific climate change adaptation strategies to mitigate the growing health impacts of temperature extremes, protect vulnerable populations and prepare healthcare systems for projected changes of emergency department presentations in the Australian Capital Territory under future climate conditions.