Montana’s Madison Range (W. Tilt)
While La Niña has thankfully delivered a few big, early-season snowstorms to parts of the West, anthropogenic climate change is decreasing seasonal snowpacks around the world. For the western United States this poses potentially catastrophic consequences on water resources, given the region’s long-held reliance on snowpack for water supply.
In a recent study, A low-to-no snow future and its impacts on water resources in the western United States, a group of researchers have examined the changes and trickle-down impacts of snow loss in the western United States where snow water equivalent declines of ~25% are predicted by 2050. Among the study’s key points:
Mountain snowpacks in the western United States have historically acted as large, natural reservoirs of water; yet, they are now harbingers of a changing climate through their signaling of a low-to-no snow future.
Diminished and more ephemeral snowpacks that melt earlier will alter groundwater and streamflow dynamics.
Low-to-no snow will impose a series of cascading hydrologic changes to the water–energy balance, including vegetation processes, surface and subsurface water storage and, ultimately, streamflow that directly impacts water management.
A re-evaluation of long-standing hydroclimatic stationarity assumptions in WUS water management is urgently needed, given the impending trickle-down impacts of a low-to-no snow future.
Co-production of knowledge between scientists and water managers can help to ensure that scientific advances provide actionable insight and support adaptation decision-making processes that unfold in the context of significant uncertainties about future conditions.
While recognizing the difficulty in determining the future direction of seasonal snowpacks, these predicted changes need to be integrated into water management practices now. Through proactive implementation of soft and hard adaptation strategies, there is potential to build resilience to extreme, episodic and, eventually, persistent low-to-no snow conditions.
The Study: A low-to-no snow future and its impacts on water resources in the western United States. Erica R. Siirila-Woodburn, Alan M. Rhoades, Benjamin J. Hatchett, Laurie S. Huning, Julia Szinai, Christina Tague, Peter S. Nico, Daniel R. Feldman, Andrew D. Jones, William D. Collins & Laurna Kaatz. Nature Reviews Earth & Environment volume 2, pages 800–819 (2021).
More: A future with little to no snow? What that means for the West and its rivers. Tara Lahan. Hatch