At a Glance
- The study looked at 4,000 drownings in 10 countries.
- It showed warming air temperatures play a role in the increasing number of drownings.
- The rates of drowning were greatest late in the winter season when ice stability declines.
Warmer winters caused by climate change are leading to more drownings, especially among young people, according to a new study from York University.
“In this study, we also looked at who was drowning, when, and what kind of activities they were doing at the time,” lead researcher Sapna Sharma said in a news release about the study. “Almost 50 percent of drowning victims are children less than 9 years old playing on the ice, while the majority of victims drowning while in vehicles, such as snowmobiles, are young adults less than 24 years old.”
The study, published in the journal PLOS One, examined 4,000 drownings in 10 countries, including Canada, Russia, Finland, Germany, Sweden and the United States. It found warming winter air temperatures were a good predictor of the number of drownings.
The research showed winter drownings increased exponentially in regions with warmer winters when air temperatures got close to 32° Fahrenheit (0°C). The largest number of drownings happened when winter air temperatures were between 23° (-5°C) and 32° when ice is less stable. The rates of drowning were greatest late in the winter season when ice stability declines.
The drownings are also most frequent in regions where indigenous traditions and livelihood require extended time on ice.
“Because we also examine trends in lake ice over hundreds of years, we know that ice-on is much later in the season and ice-off is much earlier. We are seeing these trends in lakes and rivers across the Northern Hemisphere and we found that the highest number of drowning events correspond to these times of ice-off and ice-on,” said Sharma, an associate professor of science at the university in Toronto.
“Lake ice is important as we have strong traditions for going out on the ice to skate or ice fish, and for some, it’s important for survival, such as through the construction of ice roads in northern communities that are the only way to get resources in the winter.”
Sharma told the Canadian Press the past 25 years have been the fastest-warming years in the last 150 in terms of lake ice being lost.
"In the spring, the ice melts earlier, and that's when people are using the ice a lot," she said.
Climate change also led to unpredictable and atypical weather that makes ice more dangerous, Sharma said.
As ice thaws and refreezes, its structural integrity is weakened. Gray ice forms when ice that is turned to slush by rain refreezes.
"It becomes weaker and doesn't hold as much weight," she said.
Events like Sweden's Vikingaslingan skating race and ice fishing derbies in Minnesota have had to be canceled because the ice can't be trusted, Sharma said.
The study found that countries with strong regulations about who can go on the ice, when, and for what activity, such as Italy and Germany, have low incidences of winter drownings.
Sharma said winter ice safety should be incorporated in swimming lessons for children.
“The climate is changing and it’s affecting when you can be on the ice safely. Individuals need to take that into account, especially this winter when more individuals will be out enjoying winter ice activities,” Sharma said.
“Times have changed, and the climate has changed. Winters are among the fastest-warming season, especially in Northern countries, and we’re seeing the impacts of that on our lakes, and it’s also contributing to tragedies each winter.”
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