Friday, November 19th 2021, 12:50 pm - Ice-free years will become increasingly common for northern lakes, which will create ecological, cultural, and socioeconomic consequences, experts say.
Lake Superior is the largest freshwater lake in the world by surface area and its volume is around 10 per cent of all the freshwater that exists on the planet. Many local and international communities rely on the lake for economic, cultural, and recreational reasons, but warming temperatures are threatening widespread changes to the waterbody.
A study from York University reports that since 1992, lakes in the Northern Hemisphere have been warming six times faster than any other time period in the past century. The situation is particularly concerning in Canada, where the researchers say that Lake Superior is the second fastest-warming lake in the world.
“When we were calculating our trends, we had to double and triple check because they were so fast. And we haven't seen that translate in any of our previous studies as well. So that was the alarming part, how fast things are changing,” Sapna Sharma, Associate Professor at York University and lead author of the study, told The Weather Network.
The frozen Lake Superior coastline in Michigan during the winter. (Posnov/ Moment/ Getty Images)
The study looked at the ice trends of 60 lakes around the world that have ice phenology records that were between 107 to 204 years old. The analysis revealed that on average, all of the lakes were freezing 11 days later and thawing nearly 7 days sooner, which was attributed to warm winters in the past few decades.
Lakes in cooler climates, such as those in northern regions of Russia, China, and North America, are experiencing more extreme changes than lakes closer to the equator. This is because of Arctic amplification, which is the observance that air temperatures at higher latitudes are warming more rapidly than those at southern latitudes due to melting polar ice and atmospheric circulation patterns.
There are several other lakes around the world that are also warming abnormally quickly. Ice on Japan’s Lake Suwa has been forming close to 26 days later per century since 1897 and is only freezing twice every decade. Grand Traverse Bay in Lake Michigan had one of the fastest trends of melting abnormally early, with this occurring approximately 16 days earlier each century.
Lake ice is considered to be an important indicator of the health of these ecosystems as global temperatures warm. The researchers say that less ice coverage will create ecological, cultural, and socioeconomic consequences due to changing evaporation rates, warming lake temperatures, decreased water quality, and more frequent algal blooms. Ice fishing and winter transportation will also be disrupted and potentially lost in some areas.
A woman steps across ice floes drifting apart near the shore of Lake Superior during a light snow in Grand Marais, Minnesota. (wanderluster/ E+/ Getty Images)
According to Sharma, Indigenous communities that rely on winter ice roads are particularly impacted by this warming trend.
“Ice roads are critical for connecting remote, mostly Indigenous communities, to southern locations to have access to resources and social networks. What we found is that over the last 20 years, there's been a delay in the winter road opening season by three weeks. And that's quite significant because the only transportation option is to fly out of those regions, which is very expensive.”
The study stated that ice-free years will become more common as the winter season warms and up to 5,700 northern lakes may permanently lose ice cover by 2100.
“There is an urgent need for research focused on implications of losing lake ice cover, both economically and in terms of lake ecology. Accumulating knowledge of winter ecology can improve our capacity to understand the role of ice cover on lakes, and the people who depend on ice cover, before it is lost,” the study concludes.
Thumbnail credit: Michigannut/ iStock/ Getty Images Plus