New insights on snow persistence in the Northern Hemisphere amid warming
Researchers from Dartmouth College in the United States have identified a temperature benchmark that influences whether snow remains stable across the Earth’s Northern Hemisphere under warming conditions. The threshold, relevant to winter, is at or below minus eight degrees Celsius. The findings appear in the journal Nature.
Winter snow cover plays a crucial role in supplying drinking water for billions and in sustaining irrigation for crops around the globe.
climatologists note that about 81 percent of Northern Hemisphere snow lies in regions where average winter temperatures are under minus eight degrees Celsius, home to roughly 570 million people. In addition, more than two billion people reside in areas where winter temperatures average between minus eight and zero degrees Celsius.
Analysts examined 169 river basins in the Northern Hemisphere and tracked a 40 year trend. Snow cover declined in 70 basins, rose in 12, and showed little change in the remainder.
In eight basins located in Eastern Siberia, climate change brought more snow through increased precipitation while temperatures stayed cold enough to preserve the snowpack.
Projections indicate the sharpest losses of snow are likely to occur in Europe and North America. This includes river systems such as the Hudson, Delaware, Vistula, Dnieper, Don, Danube and Neva.
Earlier observations reported glacier retreat on the Chinese side of the Altai Mountains, aligning with broader shifts in regional snow patterns observed in recent decades.
Context for policy and water management remains critical. Scientists emphasize the need for monitoring snow dynamics, especially in basins where the balance between precipitation and temperature shapes seasonal water supplies. The research highlights how regional climate changes can alter snowpacks and, by extension, water security for communities relying on snowmelt and seasonal runoff. Attribution notes point to human-driven warming as a key driver, underscoring the importance of mitigation and adaptation strategies in water resource planning. [Citation: Dartmouth College study; Nature journal]