Lake ice is a common phenomena in lakes around the northern hemisphere particularly in temperate regions and more northern in latitude. Phenology is nature’s calendar – the seasonal timing of natural trends like when birds migrate or plants flower. Lake ice phenology can be recorded as ice-in (when lakes freeze in the winter) and ice-out (when lakes freeze in the spring). By comparing the two dates, we can calculate the ice duration or length of the ice season. Observers, both scientists and non-scientists, have been recorded lake ice phenology for centuries. For example, Shinto priests in Japan have been recording ice phenology since 1397 as part of religious observations (see this article that we wrote for the story of the Shinto practice). Locally, Mohonk Lake, New Paltz, has an ice record that predates World War 2 because the Mohonk Mountain House, built on the shore of Mohonk Lake, have used the lake for refrigeration and recreation (see picture below from the Mohonk Mountain House instagram).
We can use these long-term records of lake ice phenology as indicators of climate change and did so in a new collaborative study led by Dr. Sapna Sharma (York University, Canada), Dr. Iestyn Woolway, and myself among researchers from countries around the northern hemisphere. We re-assessed ice trends for the first time since 2004 for 60 lakes by studying ice phenology records ranging from 107 to 204 years old, spanning from prior to the Industrial Revolution. We found that lakes are losing, on average, 17 days of ice cover per century. Moreover, recently, in the past 25 years, the trends were much faster than any other previous time over the century. You can read the original paper in the Journal of Geophysical Research Biogeosciences here.
The alarming trend of ice loss will ultimately decrease water quality, increase water loss, and harm economic, cultural, and recreational benefits that we enjoy from frozen lakes. A reduction in greenhouse gas emissions to curb climate change and minimize air temperature increases will be the primary way to mitigate ice loss.
The paper also received some press in popular media including an article in the Washington Post. We also wrote a short article in The Conversation about our study. Please peruse the links below for more details.
- Washington Post. Earth’s lakes are warming at a feverish pace, with the Great Lakes leading the way. https://www.washingtonpost.com/weather/2021/11/04/great-lakes-fastest-warming-study/
- The Weather Channel: https://weather.com/news/climate/video/lakes-in-northern-hemisphere-warming-alarmingly-fast
- The Toronto Star. Barrie’s Kempenfelt Bay has lost nearly a month of ice cover since 1852, new York University led study shows. https://www.thestar.com/local-barrie/news/2021/10/31/barrie-s-kempenfelt-bay-has-lost-nearly-a-month-of-ice-cover-since-1852-new-york-university-led-study-shows.html
- Simcoe.com. Barrie’s Kempenfelt Bay has lost nearly a month of ice cover since 1852, new York University led study shows. https://www.simcoe.com/news-story/10502121-barrie-s-kempenfelt-bay-has-lost-nearly-a-month-of-ice-cover-since-1852-new-york-university-led-study-shows/
- Helsingin Sanomat. https://www.hs.fi/tiede/art-2000008356794.html
- CTV News. Ice loss, toxic algal blooms: Canadian study looks at Northern Hemisphere warming lakes. https://www.ctvnews.ca/climate-and-environment/ice-loss-toxic-algae-blooms-canadian-study-looks-at-northern-hemisphere-s-warming-lakes-1.5635570
- CBC Radio. Up North with Jonathan Pinto. https://www.cbc.ca/listen/live-radio/1-84-up-north/clip/15873926-rapidly-warming-northern-lakes
- CBC News. Northern lakes losing ice coverage due to climate change. https://www.cbc.ca/news/canada/sudbury/northern-lakes-ice-coverage-climate-change-1.6221787
- YFile. Northern lakes warming six times faster in the past 25 years. https://yfile.news.yorku.ca/2021/10/24/northern-lakes-warming-six-times-faster-in-the-past-25-years/
- Digital Journal. Study finds Northern Hemisphere lakes losing ice coverage due to climate change. https://www.digitaljournal.com/tech-science/study-finds-northern-hemisphere-lakes-losing-ice-coverage-due-to-climate-change/article
- Science Daily. Northern lakes warming six times faster in the past 25 years. https://www.sciencedaily.com/releases/2021/10/211021121002.htm
- Earth.com. Northern lakes are warming at an alarming rate. https://www.earth.com/news/northern-lakes-are-warming-at-an-alarming-rate/