Stalhandske Zélie, de Ruiter Marleen C, Chambers Jonathan, Zimmermann Sandra, Colón-González Felipe J, Sairam Nivedita, Bresch David N, Kropf Chahan M
Institute for Environmental Decisions, ETH Zurich, Zurich, Switzerland; Federal Office of Meteorology and Climatology MeteoSwiss, Zurich, Switzerland.
Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
Lancet Planet Health. 2025 Aug;9(8):101295. doi: 10.1016/j.lanplh.2025.101295. Epub 2025 Aug 20.
The climate crisis is increasingly recognised as a health crisis, driven in part by the growing frequency and intensity of climate-related hazards, such as heatwaves and wildfires. These hazards can coincide, potentially leading to compound impacts. However, little is known about where and how often such combinations occur globally. This study aims to map historical population exposure to multiple interacting climate-related hazards and identify regions that have been most affected.
In this retrospective study, we analysed global data from the 2024 Lancet Countdown on health and climate change, International Best Track Archive for Climate Stewardship, The Inter-Sectoral Impact Model Intercomparison Project, and WorldPop from 2003 to 2021 at a 0·25° resolution to examine the population that was exposed to combinations of six climate hazards: heatwaves, droughts, wildfires (PM), extreme precipitation, river floods, and tropical cyclones. We identified administrative level 1 regions based on several hotspot definitions and did detailed case studies in the most exposed regions.
We detail how frequently people at each grid point have been exposed to various combinations of hazards, revealing both regular patterns and rare, region-specific occurrences. Our analysis indicates an increase in per-person exposure to many hazards during the study period, with a more pronounced rise in multihazard exposure than single-hazards. Between 2003-12 and 2012-21, per-person exposure to three or more hazards increased by 69%. Heatwaves were the most common hazard and also showed the clearest trend, largely driving the observed increases in both single-hazard and multihazard exposure. Multihazard hotspots vary depending on the specific definition used. For instance, exposure to multiple hazards is explained by the seasonality of hazards, which leads them to co-occur in the same months. Additionally, incorporating specific vulnerable age groups into our analysis reveals hotspots that consider the sociodemographic characteristics of the regions.
These findings highlight the importance of incorporating multihazards into climate and health risk assessments. Our study enables an examination of historical events to deepen our understanding of interactions between hazards. Given the rarity of many hazard combinations, traditional epidemiological methods might fall short. Thus, alternative approaches, such as storyline development, are essential to enhance our preparation for future multihazard occurrences. This work finally serves as a crucial baseline future multihazard risk assessment under different climate and socioeconomic scenarios.
MYRIAD-EU, Netherlands Organisation for Scientific Research, Horizon 2020, and German Academic Scholarship Foundation.
气候危机日益被视为一场健康危机，部分原因是与气候相关的灾害（如热浪和野火）发生频率和强度不断增加。这些灾害可能同时发生，从而可能导致复合影响。然而，对于全球范围内此类灾害组合发生的地点和频率，我们知之甚少。本研究旨在绘制历史上人口暴露于多种相互作用的气候相关灾害的情况，并确定受影响最严重的地区。
在这项回顾性研究中，我们分析了来自《柳叶刀》2024年健康与气候变化倒计时、国际气候管理最佳轨迹档案、跨部门影响模型比较项目以及2003年至2021年分辨率为0.25°的世界人口数据，以研究暴露于六种气候灾害组合（热浪、干旱、野火（颗粒物）、极端降水、河流洪水和热带气旋）的人口情况。我们根据几种热点定义确定了一级行政区，并在受影响最严重的地区进行了详细的案例研究。
我们详细说明了每个网格点的人口暴露于各种灾害组合的频率，揭示了既有规律的模式，也有罕见的、特定区域的情况。我们的分析表明，在研究期间，人均暴露于多种灾害的情况有所增加，多灾害暴露的增加比单一灾害更为明显。在2003 - 2012年和2012 - 2021年期间，人均暴露于三种或更多灾害的情况增加了69%。热浪是最常见的灾害，也呈现出最明显的趋势，在很大程度上推动了单一灾害和多灾害暴露的增加。多灾害热点因所使用的具体定义而异。例如，灾害的季节性解释了多种灾害的暴露情况，导致它们在同一月份同时发生。此外，将特定的脆弱年龄组纳入我们的分析，揭示了考虑到地区社会人口特征的热点地区。
这些发现凸显了将多种灾害纳入气候和健康风险评估的重要性。我们的研究能够审视历史事件，以加深我们对灾害之间相互作用的理解。鉴于许多灾害组合的罕见性传统流行病学方法可能不够充分。因此，诸如情景开发等替代方法对于加强我们对未来多灾害事件的准备至关重要。这项工作最终为不同气候和社会经济情景下的未来多灾害风险评估提供了关键基线。
欧盟MYRIAD项目、荷兰科学研究组织、地平线2020计划以及德国学术奖学金基金会。
