The lakes in the Great Lakes region and around the world don’t freeze over as they did in past centuries. That has serious consequences for people, wildlife, and the environment as a whole. That’s been shown by many scientific studies — but the consequences of that reduction of ice coverage have been scattered across many scientific journals.
A new study in the journal Science works to gather those effects in one place, for a broader perspective.
“The goal of this was really to make a review that was useful for scientists, but also useful for the general public to be able to look at those consequences in a simple summary,” said Hilary Dugan, Associate Professor at the University of Wisconsin-Madison. She was one of 16 authors scattered across the globe who collaborated on the study.
News coverage by Michigan Public reporters and our colleagues in the Great Lakes News Collaborative have been documenting these consequences in the Great Lakes region for many years here, here, and here, for example.
More recent reports cover the historic decreases in ice coverage of the Great Lakes here, here, and here. NPR contributed this story in 2022.
So, some of the changes to the Great Lakes and the inland lakes of the region won’t come as a great surprise to people who pay attention. But there’s more going on than has been studied in just our region of the world.
Consequences of less ice on lakes
While there’s much more to be studied, here’s a brief summary of what this study has compiled from around the world:
- The ways people are able to take advantage of iced-over lakes are being affected. Ice festivals and cultural events such as ice hockey tournaments, ice roads for transportation and ice bridge connections, for example Mackinac Island to St. Ignace by snowmobile, as well as the spiritual connections some people have with the ice are being disturbed.
- Ice fishing is not only part of some cultures, but a source of food for many people. Access to certain kinds of fish and even the nutritional quality of fish can be affected by lack of ice.
- Winters could become wetter and warmer (as reported here) because of a lack of ice coverage. Open water contributes to lake-effect snow.
- Scientists suggest that longer ice cover, cooling lake water, lowers nitrous oxide emissions, a potent greenhouse gas.
- Lake ice creates unique ecosystem for native biodiversity (for example, some native species need ice protection for eggs to reproduce, such as whitefish).
- Without ice, there could be further declines in native organisms and increased chances for further non-native species invading lakes.
- Less ice could mean more algal blooms that are linked to warmer temperatures which could lead to nutrient overloads. That could mean an increased amount of cyanobacteria appearing in lakes, which is a current trend.
More lake ice study needed
Dugan said one of the reasons we’re only putting together some of this information now is that there are few researchers spending time studying ice-covered lakes.
“Traditionally, we get out on lake in the summer and study them really intensively. And there’s been a pretty major awareness of really needing to get more data in the winter to be able to answer some of these questions (about ice cover).”
As the Great Lakes and the regional inland lakes continue to see less ice over the decades, Dugan said we will still see some significant ice some years.
“We’re in this climate zone, where we can have mild winters punctuated by these massive polar vortex events that bring really cold weather. And so, winter overall, it’s warming, but it’s also getting a lot more variable. And so we’re going to live through some interesting winters that are going to be all over the place.”
She concluded we will still see some good lake ice years. However, it’s going to be a lot more uncertain as climate disruption continues because of continued fossil fuel use.
