Winter ice cover on lakes across the Northern Hemisphere could shrink by around 40 days by the end of the century if greenhouse gas emissions remain high, according to a study published in the Proceedings of the National Academy of Sciences (PNAS).
Researchers analysed ice records from 724 lakes between 2000 and 2022 and found that spring ice melt is occurring much faster than autumn freeze up is being delayed. Once average winter temperatures rise above critical thresholds between -13.7°C and -6.8°C, lake ice loss accelerates sharply, with sensitivity to warming increasing by up to 22 times.
The study found that nearly 23 per cent of the analysed lakes have already crossed these thresholds, a figure projected to rise to 70 per cent under a high emissions scenario.
Scientists said shrinking ice cover could affect freshwater ecosystems by altering water quality, disrupting aquatic life and impacting communities that depend on stable winter ice.