Forecasting the Permanent Loss of Lake Ice in the Northern Hemisphere Within the 21st Century

Lake ice cover is essential to conserving the global freshwater supply for the 50 million lakes that freeze each winter. Here, we ask when lakes across the Northern Hemisphere may permanently lose ice cover. A K‐means cluster analysis from 31 lakes identified four clusters of lakes vulnerable to losing ice cover, including shallow and deep lakes in regions where winter air temperatures hover ∼0 °C and larger and deeper lakes in colder regions. By the end of this century, we estimate that up to 5,679 lakes of 1.35 million HydroLAKES may permanently lose ice cover if greenhouse gas emissions (GHG) continue to be emitted at current levels. In the Northern Hemisphere, lakes in southern and coastal regions, some of which are among the largest lakes in the world and in close proximity to large human populations, are the most vulnerable to permanently losing ice.