Study warns that climate trends may keep Michigan lakes from freezing

Michiganders who enjoy ice fishing, skating or simply walking on the frozen surfaces of the state’s many freshwater lakes may find that these pastimes are no longer possible if current warming trends continue. A study recently published in the journal Nature Climate Change reveals that more than a thousand Michigan lakes that typically froze over in the past freeze only intermittently now, and the number of irregularly-freezing lakes could increase by 700 if temperatures rise another two degrees.

The consequences of this trend extend beyond the winter experience of Michigan residents and have wide-reaching effects on the ecosystem. John Magnuson, one of the co-authors of the study, said in an interview with Bridge Magazine that ice acts as a “reset” button for lakes, preventing them from warming up too quickly in the summer and deterring harmful algal blooms. “Lake ice is a really good index of what’s happening to weather and climate change variation,” said Magnuson. Scientists don’t yet understand all of the harm that the loss of freshwater lake ice may do to local ecosystems, but they do know that ice cover has major impacts on the biological life and chemical makeup of lakes.

If lakes start failing to freeze, scientists anticipate that the negative implications of the change could be far-reaching. As the authors of the study explain, the problem of warming lakes isn’t strictly ecological. Lake ice has long provided an outlet of recreation in the cold months of winter, not only in Michigan but around the world. Some are now concerned that few outdoor skating opportunities will exist by the late 21st century. For certain groups of people, such as the indigenous communities of Canada, frozen lakes offer the only means of accessing remote communities in the winter. To the researchers behind the study, this represents a great loss and stresses “the importance of climate mitigation strategies to preserve ecosystem structure and function, as well as local winter cultural heritage.”