Vanishing Winters and Shrinking Ice: Ecosystem Services and Societal Impacts in the Laurentian Great Lakes

Abstract

The Laurentian Great Lakes are undergoing rapid winter transformations, with profound implications for human societies. Winter air temperatures have increased, accelerating ice loss since the mid‐1990s. These trends are altering thermal regimes, shifting precipitation from snow to rain, and increasing winter runoff and nutrient fluxes, with cascading effects across physical, chemical, and biological systems. Using the Millennium Ecosystem Assessment framework, we synthesize how warming winters affect supporting, regulating, provisioning, and cultural ecosystem services, as well as their positive and negative socioeconomic implications for the Sustainable Development Goals. Winter warming is altering supporting services by reducing the stability and extent of under‐ice habitats that provide refugia for biodiversity and disrupting nutrient cycling. Regulating services are also affected, through increased greenhouse gas emissions, shoreline erosion and flooding, altered disease dynamics and changes in lake‐effect snowfall. Provisioning services, such as freshwater supply and fisheries, are increasingly vulnerable to harmful algal blooms, infrastructure disruptions, and reduced habitat for cold‐water species. Cultural and recreational activities including ice fishing, Indigenous traditions, and winter tourism are also threatened, while unstable ice may increase drowning risks. Although reduced ice cover may benefit navigation and summer recreation, these gains are outweighed by broader ecological and cultural losses. Collectively, these findings show that lake ice functions as a mediating variable regulating interconnected ecological and societal processes. Its loss threatens ecosystem resilience and heightens socioeconomic vulnerabilities for the 40 million people who depend on the Great Lakes. Addressing these challenges will require cross‐border cooperation.