Increased winter drownings in ice-covered regions with warmer winters

Winter activities on ice are culturally important for many countries, yet they constitute a high safety risk depending upon the stability of the ice. Because consistently cold periods are required to form stable and thick ice, warmer winters could degrade ice conditions and increase the likelihood of falling through the ice. This study provides the first large-scale assessment of winter drowning from 10 Northern Hemisphere countries. We documented over 4000 winter drowning events. Winter drownings increased exponentially in regions with warmer winters when air temperatures neared 0 ̊C. The largest number of drownings occurred when winter air temperatures were between -5 ̊C and 0 ̊C, when ice is less stable, and also in regions where indigenous traditions and livelihood require extended time on ice. Rates of drowning were greatest late in the winter season when ice stability declines. Children and adults up to the age of 39 were at the highest risk of winter drownings. Beyond temperature, differences in cultures, regulations, and human behaviours can be important additional risk factors. Our findings indicate the potential for increased human mortality with warmer winter air temperatures. Incorporating drowning prevention plans would improve adaptation strategies to a changing climate. Funding was provided to SS by the Ontario Ministry of Research, Innovation and Science Early Researcher Award and York University Research Chair programme. Funding support for BAD was provided by Kempestiftelserna. AL was supported by Estonian Research Council Grant PSG 32. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Funding was provided to SS by the Ontario Ministry of Research, Innovation and Science Early Researcher Award and York University Research Chair programme. Funding support for BAD was provided by Kempestiftelserna. AL was supported by Estonian Research Council Grant PSG 32. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.